Insect Identification Part                                                                    Coleoptera Part 1.                                                                                                                                 New Order of Insects A new order of insects has been identified in a discovery that researchers say is equivalent to finding a live saber-tooth tiger. This first discovery of a new insect order since 1915 brings the total number of insect orders to 31. The insect is known by scientists as Mantophasmatodea, a predatory animal which resembles a mix between a stick insect and a preying mantis. It was originally found in a 45 million year old piece of Baltic amber by Oliver Zompro, a doctoral student at the Max-Planck Institute for Limnology in Ploen, Germany. A nymph of a yet undescribed species of Mantophasmatodea from Brandberg massif. (Photo �Piotr Naskrecki, Conservation International) Subsequently, the existence of a living population of these insects was discovered on the Brandberg Mountain in western Namibia by a team of scientists from the National Museum of Namibia in Windhoek. Living individuals were confirmed on a recently completed rediscovery expedition, funded by Conservation International, an organization based in Washington, DC that works in 30 countries on four continents to protect the Earth's richest regions of plant and animal diversity. These insects are some of the last witnesses of the time when Africa and America were part of the same landmass, scientists said. This discovery is comparable to finding a living mastodon or saber-tooth tiger, said Piotr Naskrecki, director of Conservation International's new Invertebrate Diversity Initiative, who attended the rediscovery mission and photographed the new order. "It tells us that there are places on Earth that act as protective pockets, preserving tiny glimpses of what life was like millions of years ago," said Naskrecki. Brandberg Massif (Photo courtesy National Museum of Namibia) The new insect order may have lived in Brandberg's unique habitat for millions of years with no interaction with other species. Brandberg is a 120 million year old massif, isolated from other mountains by hundreds of miles of barren sand. Invertebrates are not seen as charismatic as tigers, pandas or dolphins, so they are often overlooked as conservation priorities. But insects, with more than 1.2 million known species, represent more than 80 percent of all living creatures on Earth. Harvard University professor Edward O. Wilson, a two time Pulitzer Prize winning author and Conservation International board member, has made the study of insects his life work and the foundation of the science of evolutionary biology. "If human beings were to disappear tomorrow, the world would go on," Dr. Wilson said, "but if invertebrates were to disappear, I doubt that the human species could last more than a few months."

                                                                           Order Mecoptera-Scorpionflies

Mecoptera (from the Greek: meco- = "long", -ptera = "wings") is an order of insects with about 550 species in nine families worldwide. Mecoptera are called scorpionflies after their largest family, Panorpidae, in which the males have enlarged genitals that look similar to the stinger of a scorpion. The Bittacidae, or hangingflies, are a prominent family of elongate insects known for their elaborate mating rituals, in which females choose mates based on the quality of gift prey offered by various males. While living Mecoptera are overwhelmingly predators or consumers of dead organisms, their ancestors might have played an important role before the evolution of other insects in pollinating extinct gymnosperms.

This order contains small to medium insects with slender, elongated, bodies. They have relatively simple mouthparts, with long mandibles and fleshy palps, which resemble those of the more primitive true flies. Most Mecoptera feed on vegetation in moist environments; in hotter climates, they may therefore be active only for short periods of the year. The wings are narrow with numerous cross-veins, and somewhat resemble those of primitive insects such as mayflies. A few genera, however, have reduced wings, or have lost them altogether. The abdomen is cylindrical, and typically curves upwards in the male, superficially resembling the tail of a scorpion.

                                                                           

                                                                                                      Typical Male Mecopteran.

The female lays the eggs in close contact with moisture, and the eggs typically absorb water and increase in size after deposition. In species that live in hot conditions, the eggs may not hatch for several months, the larvae only emerging when the dry season has finished. More typically, however, they hatch after a relatively short period of time.

The larvae are usually quite caterpillar-like, with short, clawed, true legs, and a number of abdominal prolegs. They have a sclerotized head with compound eyes and mandibulate mouthparts. The tenth abdominal segment bears either a suction disc, or, less commonly, a pair of hooks. They generally eat vegetation or scavenge for dead insects, although some predatory larvae are known.

The larva crawls into the soil or decaying wood to pupate, and does not spin a cocoon. The pupae are exarate, meaning that the limbs are free of the body, and are able to move their mandibles, but are otherwise entirely non-motile. In drier environments, they may spend several months in diapause, before emerging as adults once the conditions are more suitable.

It has been proposed that extinct Mecoptera species were important plant pollinators. Early non-angiosperm gymnosperm seed plants during the late Middle Jurassic to mid–Early Cretaceous period have been believed to be mainly wind-pollinated. However examination of fossil Mecoptera show that they had siphon feeding apparatus that could fertilize early gymnosperms by feeding on their nectar and pollen. The lack of iron enrichment in their fossilized proboscis rules out a use in blood drinking. One question over this suggestion is that so far pollen has not been found associated with these feeding parts which is surprising for the amber-encased insects which should have preserved pollen but "further fossils may provide this information".

 

Food items such as caterpillars, bugs, and flies are offered to be eaten during copulation. The female is first attracted by a pheromone emitted by one or more vesicles or pouches at the end of the male's abdomen. When the female is near, the vesicles are retracted. The female examines the offering while the male searches for her genitalia. If the gift is rejected, the female flies away. If the gift is accepted, the genitalia of the male couples with that of the female, who lowers herself until she is hanging upside down. She consumes the offering during copulation. The male supports the female by holding her legs or the prey. Field observations show that both sexes mate several times per day. Small or unacceptable offerings result in no or a very short copulation time. Duration depends on the size of the gift. It has been observed that prey 3 to 14 mm long will provide 1 to 17 minutes of copulation. Given larger prey the size of house flies copulation lasts 20 to 29 minutes.

 

 

 

                                                                       Order Coleoptera-Beetles

 

         This, by far, is the largest order of insects.  In fact, it is thought that about 25% of all plant and animal species on the earth are beetles.  Being such a large order, it follows that the largest and smallest species of insects belong to this order.  The smallest beetle species is about the size of the smallest visible dot (featherwing beetle) while the largest is an 8-inch giant longhorned beetle from South America.

 

          The main diagnostic characteristic of beetles is the hardened leather-like first pair of wings that fit over and meet in a straight line down the abdomen (e. Most beetles are capable of flight as the second pair of wings is typically folded under the elytra.  When a beetle is ready to fly, the protective elytra are raised and the flight wings unfold.

 

                                                                                              

A weevil beetle illustrating elytra

 

 

FAMILY-CHRYSOMELIDAE-LEAF BEETLES

 

          This is one of the larger and more diverse appearing families of beetles in the world.  When my students are taking a test and don’t know the answer to identification of a beetle family, I always say “guess Chrysomelidae.”  There are over 20,000 described species worldwide and approximately 14,000 species in North America.  Most leaf beetles are brightly colored, frequently adorned with spots and stripes and are medium in size.  They are similar in size and color to ladybugs and are most often confused with the ladybugs. They can be easily separated from that family by the antennae alone.  Leaf beetles have filiform antennae while the ladybugs have short capitate or clubbed antennae.  In addition the leaf beetles exhibit a variety of shapes while the ladybugs are slightly oval to round in shape. Finally leaf beetles possess four flattened tarsal segments on each leg.  All leaf beetles are phytophagus, with the adults typically feeding on leaf tissue and the larvae feeding on roots, stems or leaves, depending on the species.   Some species are pests while a few are considered beneficial.

 

             

 

               A leaf beetle with elongate filiform antennae and flattened tarsal segments.

 

Asparagus Beetle.  This species is distributed throughout North America and Europe.  It is host specific on asparagus, becoming a pest by feeding on the tip of spears and staining the crop with its black feces.  There is a closely related species, the spotted asparagus beetle that does similar damage. 

The adult is 1/4 inch in length, has a bluish-black head, legs and antennae tinged with green, a reddish thorax, and wing covers marked by yellowish patches and reddish borders. The larva of the common asparagus beetle is dark gray to olive-green with black legs and head. The spotted asparagus beetle is slightly larger and more robust than the common asparagus beetle. The adults are reddish-orange in color with black antennae, eyes and underside of the thorax. Each wing cover has six distinct black spots.

Both the larvae and the adults of the common asparagus beetle damage the asparagus plants. The overwintered adults emerge and begin to feed on the tender growing tips of newly sprouted asparagus. They chew holes in the plant and cause a brownish discoloration of the tissue. The grubs will feed on the tender young tips and on foliage. The plant growth is seriously reduced and proper root development prevented, causing a decrease in the size and quality of the crop. The spotted asparagus beetle causes the most injury in the early season when the adults attack the growing tips and sometimes eat the buds of newly sprouted asparagus. The beetles also feed on foliage, eating out irregular areas. The larvae cause little damage because they feed inside the berries.

The adults of the common asparagus beetles overwinter in sheltered places such as piles of rubbish and heaps of old asparagus tops. The beetles emerge from their shelter and begin feeding on the tender tips of new shoots. They soon lay eggs on the young shoots. The eggs are elongate, oval, and deposited either singly or in rows of two to eight. Later in the season the eggs are laid on leaves and flower stems. The eggs hatch in three to eight days and the grubs begin feeding on the tender tips. When the grubs mature, they drop to the ground and construct a small earthen cell where they transform into pale yellowish pupae. The adult beetles emerge from the pupae. There may be two or more generations a year depending on the climate. The adult spotted asparagus beetles overwinter in piles of debris. They leave their winter quarters about one week later than the common asparagus beetles and begin to feed on the tender young shoots as well. They do not deposit eggs until the plant begins to blossom, about three weeks after emergence. The egg is deposited singly on plants, usually those bearing fruit. The egg is 0.5 mm (1/25 inch in length, olive brown, and attached to the leaf by one side. The larvae of the spotted asparagus beetle hatch in seven to twelve days and are yellowish-orange in color with a black head and legs. The larva finds a berry and enters it at the blossom end. Inside the berry it feeds on the seeds and it may attack three or four berries before it is mature. When fully grown, it drops to the ground by a silken thread and spins a cocoon just under the soil surface

Cutting the shoots very clean and just below ground level every day or two during the cutting season will tend to remove the eggs of the common asparagus beetle before the larvae can establish themselves in a home garden patch. In small gardens, gathering and destroying the asparagus berries will help to give control of the spotted asparagus beetle. Apply insecticides labeled for use on the asparagus beetles when the beetles first appear. Apply as frequently as needed but do not repeat applications within three days. Be sure to check the number of days to harvest before applying any pesticide to edible crops.

   

 

Asparagus flea beetles, Crioceris asparagi. Image courtesy of

Clemson University Entomology.

 

Flea Beetles.  Flea beetles are a rather large group of small beetles (typically ¼ inch or less in length).  Depending on the species they are uniform in color to striped.  One distinguishing characteristic of these beetles is that the hind femur is greatly swollen.  The adults of these beetles are quite active and readily feed on the leaves of a variety of plants (including crops), with typical damage consisting of small holes (Figure 102).  Common pests include the tobacco flea beetle, spinach flea beetle, eggplant flea beetle and corn flea beetle.

 

                                                                                                            

                                                          A flea beetle-characterized by enlarged femur (arrow) on hind leg.   Image courtesy of Dave Britton.           

  They occasionally damage flowers, shrubs and even trees. Adult beetles, which produce most plant injuries, are typically small, often shiny, and have    large rear legs that allow them to jump like a flea when disturbed.

Flea beetles produce a characteristic injury known as "shot holing." The adults chew many small holes or pits in the leaves, which make them look as if they have been damaged by fine buckshot. Young plants and seedlings are particularly susceptible. Growth may be seriously retarded and plants even killed. Leaf feeding also damages plant appearance. This can be important among certain ornamentals and leafy vegetables.

                                                                    

                                                                      Typical flea beetle damage-consisting of small holes eaten in leaves.

Although flea beetles are common, injuries often are insignificant to plant health. On established plants, 10 to 20 percent or more of the leaf area must be destroyed before there is any effect on yields. The plants most likely to benefit from treatment are more sensitive seedlings, plants grown for ornamental purposes or for edible greens, and potatoes that may be affected by tuber flea beetle larvae.

Because seedlings are most at risk, use transplants or plant seeds in a well-prepared seedbed to hasten growth and allow plants to overcome injury. In home gardens, high seeding rates can be effective

Trap crops work in some situations. This is accomplished by planting a highly favored crop to attract flea beetles away from the main crop. Radish or daikon can protect other seedling crucifers (e.g., broccoli, cabbage, Brussels sprouts) that are more sensitive to western cabbage flea beetle. The trap crop may then be harvested or destroyed after the main crop has established itself sufficiently to outgrow flea beetle injury.

It may also be possible to avoid injury by scheduling plantings so that seedlings are emerging during periods of low flea beetle activity.

Floating row covers or other screening can exclude the beetles during seedling establishment. In isolated plantings, thick mulches may also help reduce the number of flea beetles by interfering with activity of the root and soil stages. Flea beetles can be vacuumed off foliage, but this practice must be repeated frequently. Reinvasion of plants can be rapid.

Colorado Potato Beetle-Leptinotarsa decemlineata. The Colorado potato beetle is one of the exceptions to the generalization that almost all our major agricultural pests are those that have been introduced from other countries.  Naturally occurring insects in an area typically have a full complement of predators and parasites that normally keep them under control.   Unfortunately when we accidentally introduce a potential pest from another country, we leave behind those beneficial insects.  The Colorado potato beetle was first discovered naturally occurring in the West in 1820.  At that time it was quite uncommon, feeding on buffalo bur, a weed.  After settlers (many coming from Ireland and the great potato famine) introduced the potato into the area, this insect switched over and became a major problem on that crop. 

The Colorado potato beetle (- also known as the Colorado beetle, ten-striped spearman, the ten-lined potato beetle, potato bug - is an important pest of potato crops. It is approximately 10 mm (0.4 inches) long, with a bright yellow/orange body and 5 bold brown stripes along the length of each of its elytra, and it can easily be confused with its close cousin and look-alike, the false potato beetle. The beetle was described in 1824 by Thomas Say from specimens collected in the Rocky Mountains on buffalo-bur, Solanum rostratum. The origin of the beetle is somewhat unclear, but it seems to be that Colorado and Mexico are a part of its native distribution in southwestern North America.

Colorado potato beetle females are very prolific; they can lay as many as 800 eggs. The eggs are yellow to orange, and are about 1.5 mm long. They are usually deposited in batches of about 30 on the underside of host leaves. Development of all life stages depends on temperature. After 4-15 days, the eggs hatch into reddish-brown larvae with humped backs and two rows of dark brown spots on either side. They feed on the leaves. Larvae progress through four distinct growth stages (instars). First instars are about 1.5 mm long; the fourth is about 8 mm long. The larvae in the accompanying picture are third instars. The first through third instars each last about 2-3 days; the fourth, 4-7 days. Upon reaching full size, each fourth instar spends an additional several days as a non-feeding prepupa, which can be recognized by its inactivity and lighter coloration. The prepupae drop to the soil and burrow to a depth of several inches, then pupate. Depending on temperature, light-regime and host quality, the adults may emerge in a few weeks to continue the life cycle, or enter diapause and delay emergence until spring. They then return to their host plant to mate and feed. In some locations, 3 or more generations may occur each growing season.

The Colorado beetle is a serious crop pest of potatoes. They may also cause significant damage to tomatoes and eggplants. Both adults and larvae feed on foliage and may completely eliminate the crop. Insecticides are currently the main method of beetle control on commercial farms. However, chemicals are often unsuccessful when used against this pest because of the beetle's resistance to toxins and ability to rapidly develop resistance to them. The Colorado potato beetle has developed resistance to all major insecticide classes. In the United Kingdom, where the Colorado beetle is a rare visitor on imported farm produce, it is a notifiable pest: any found must be reported to DEFRA.

High fecundity usually allows Colorado potato beetle populations to withstand natural enemy pressure. Still, in the absence of insecticides natural enemies can sometimes reach densities capable of reducing Colorado potato beetle numbers below economically damaging levels.

               

 

                     Adults of the Colorado Potato Beetle.   Image Courtesy of USDA-US Forest Service.

Western Spotted Cucumber Beetle-Diabrotica undecimpunctata undecimpunctata. This is a difficult species to control as the adults are very active, flying from field to field and are even capable of migrating over 400 miles in a few days. The spotted cucumber beetle (Diabrotica undecimpunctata) is a major agricultural pest insect. In the adult form it eats and damages leaves of many crops, including cucumbers, soybeans, cotton, beans and many others. In the larval form, which is known as the southern corn rootworm, it tunnels through the roots of young plants, stunting or killing them. These native pests have a wide range of host plants, but will readily infest a field of crop plants, most notoriously corn.

                                                                                                  

 

        Twelve spotted and stripped cucumber beetles-southern corn rootworm), Diabrotica undecimpunctata. .

Adult beetles are greenish-yellow with six large black spots on each elytron. They are about half a centimeter long. The larvae are yellowish and wormlike. The spotted cucumber beetle has three subspecies, each with a different common name; the spotted cucumber beetle (a.k.a. Southern corn rootworm) is Diabrotica undecimpunctata howardi the Western cucumber beetle is Diabrotica undecimpunctata  

Striped and spotted cucumber beetles can cause serious losses in cucumbers, muskmelons, and watermelons in Kentucky. Cucumber beetles are a major concern to muskmelon and cucumber growers because they vector the bacterium that causes a disease, bacterial wilt of cucurbits. While the adults feed mainly on foliage, pollen and flowers, their feeding on melon rinds late in the season may reduce market quality. Larvae of these insects feed on roots and stems, but this damage is minimal compared to the potential losses due to bacterial wilt.  Striped cucumber beetles are yellow-green with three black stripes down the back and are 1/4 inch long.

Although similar in appearance, the striped cucumber beetle and the western corn rootworm are not the same. The stripes on the striped cucumber beetle are straighter than those on the western corn rootworm. Additionally, the middle segment (tibia) of the hind leg on the striped cucumber beetle is yellow, while that on the western corn rootworm is black. The spotted cucumber beetle (also known as the southern corn rootworm), also 1/4 inches long, is yellow-green with 12 black spots on its back.

Biology. Cucumber beetles overwinter as adults in protected areas near buildings, in fence rows, or in wood lots. They become active in mid-spring, when temperatures begin to increase. Currently, there is no good method for predicting when activity will begin. Beetles quickly locate host plants in the spring. The adults feed and females deposit eggs in cracks in the soil at the base of cucurbits. The eggs hatch and the larvae feed on the roots. These larvae will pupate in the soil, later in the summer the next generation of beetles will emerge. These beetles will also feed on the cucumber and melon plants, including the fruit and overwinter until the next spring.

Bacterial Wilt. The bacterium that causes bacterial wilt overwinters in the gut of some of the striped cucumber beetles. When beetles become active in the spring and begin feeding, they spread the bacterium either through their feces or from contaminated mouthparts. Chewing damage on young leaves or cotyledons open entry points for the pathogen. Once inside the plant, the bacterium multiplies quickly in the vascular system, producing blockages that cause the leaves to wilt. Beetles are attracted to infected plants and can pick up the bacterium and move it to healthy plants.

The first symptom of bacterial wilt on cucumber and muskmelon is a distinct flagging of lateral and individual leaves. Beetle feeding is not always obvious on wilted leaves. Soon, adjacent leaves and finally the entire vine will wilt. The wilting spreads as the multiplying bacteria move within the vascular system of the plant. Eventually, the entire plant wilts and dies. There is nothing that can be done to save an infected plant. The only way to avoid bacterial wilt is to prevent the beetles from feeding on the plant. Fruit produced on a wilting plant usually will not be marketable.

                                                                                               

                                                                                                                        Typical Bacterial Wilt. Image Courtesy EEshie.

One way to determine if bacterial wilt has infected a plant is to cut the stem and squeeze both cut ends. A sticky sap will ooze from the water conducting tissues of the stem. If you push the cut ends of the stem together and slowly pull them apart, you will be able to see a roping effect if bacteria are present. This sap contains millions of bacteria.

 Management. Begin cucumber beetle control as soon as seedlings emerge. Early treatment is essential for beetle management in large commercial muskmelon or cucumber operations. A single post-transplant soil drench with Admire or Platinum can provide near season-long control. Repeated applications of contact insecticides are necessary to protect muskmelon plants from beetle feeding and transmission of bacterial wilt. There is usually a peak in beetle activity each spring that lasts two to four weeks. This is the most important time to control the beetles. Applications of foliar insecticides may be required twice per week during peak beetle activity. Because watermelon is not susceptible to the wilt disease, protection is necessary only when plants are small and beetle populations are high.

For the home gardener, plants can be protected when they are small by mechanical means. Row covers, screens or cones over small plants are effective means of excluding cucumber beetles in home planting.

Eucalyptus Leaf Beetle.  A large number of introduced Eucalyptus pests have invaded California over the last ten years, including boring beetles, psyllids, gall forming wasps, and leaf chewing beetles in the family Chrysomelidae. The blue gum psyllid was the first to become a pest of ornamental eucalyptus, silver-leaved mountain gum or baby blue gum, and Eucalyptus pulverulenta Sims. The blue gum psyllid was not a pest for long, however, due to the introduction of Australian parasitoids.

Eucalyptus leaf beetle is a new pest of ornamental eucalyptus and was introduced from Australia into southern California around 2003. It is not controlled by native parasites or predators. In Australia it is commonly known as one of the eucalyptus tortoise beetle species. It is known as an outbreak pest of commercial E. globules, blue gum plantations in southeastern Australia.

Eucalyptus leaf beetle females prefer to oviposit batches of 30-60 eggs on younger foliage; whereas, adults feed on older foliage. Hatchlings feed gregariously on the younger foliage causing damage to leaf edges that resembles caterpillar feeding damage, and it can be quite extensive. The immature stages of Eucalyptus leaf beetle are daytime feeders. In contrast, the Australian tortoise beetle, Tracymela sloanei, feeds at night.

The Eucalyptus leaf beetle mostly feeds on landscape planted blue gum in San Diego, Orange and Riverside Counties. Recently, however, it has become a pest of field grown baby blue eucalyptus grown for cut foliage in northern San Diego County.

Both beetle species, C. m-fuscum and T. sloanei, are similar in size, about the size of a big ladybug. Eucalyptus leaf beetle adults are gray to reddish brown and the larvae are greenish-gray. The Australian tortoise beetle adult and larvae are both dark brown.

At present, research on pesticide efficacy against Eucalyptus leaf beetle is lacking. Based on studies of these pests in field nurseries and eucalyptus stands, long–term control may be achieved by a soil drench application of the systemic neonicotinoid insecticides imidacloprid or clothianidin (for use by commercial applicators only). Foliar sprays of broad-spectrum insecticides such as the carbamate carbaryl or pyrethroids, including cyfluthrin and permethrin may also be effective against adults and larvae. It is very important, however, to remember that the blue gum psyllid is under excellent control by beneficials, and that these products may well interrupt biological control and cause resurgence of the psyllid to serious pest status.

 

 

 

         Eucalyptus Leaf Beetle Larvae.  Image Courtesy of Peter Chew.

 

Klamath Beetle. Not all leaf beetles are necessarily destructive.  Control of Klamath weed is a success story in California. This noxious weed (also known as Saint John’s Wort) became a major pest in northern California when accidentally introduced in the early 1900s.  The USDA knew that the weed wasn’t a pest in the country from which it was introduced.  After searching for the reason why, they found that beetles were controlling it.  Two types of leaf eating beetles were introduced in 1946 to control the spread of Klamath weed. One beetle was soon successful, and continues to control Klamath weed today. They now confine the weed to small patches, rather than dominating the rangeland or roadsides.  This was one of the first successful cases of an insect being introduced into the US for weed control.

 

                 

 

                                                                                                           Klamath weed beetle, Chrysolina quadrigemina.   Image courtesy of Univar, Inc.

Alligatorweed Flea Beetle, Agasicles hygrophila. Alligator weed has been a waterway pest in the United States since it was introduced from South America in the 1890s. It forms dense, impenetrable mats that float on the surface and can also exist during drought conditions in a terrestrial form.  Agasicles hygrophila, native to Brazil, was purposefully introduced in California and South Carolina in 1964 by the U.S. Army Corps of Engineers to control the invasive alligator weed. It was subsequently released throughout Florida and all southeastern coastal states to Texas beginning in that same year to control the spread of the plant.

                                                                         

 

                                                                                        Alligatorweed Flea Beetle.  Image Courtesy of USDA-ARS Gary Buckingham.

Alligatorweed was targeted for biological control because herbicide-based weed management had proved difficult and ineffective. In addition to A. hygrophila, two additional host-specific South American insects were identified, evaluated, and intentionally released for the purpose of biocontrol: the alligatorweed thrips, Amynothrips andersoni, and the alligatorweed stem borer, Vogtia malloi.

Since its release, A. hygrophila has been highly successful at controlling the spread of aquatic alligatorweed but has had little effect against the terrestrial form. The insect has been purposefully introduced elsewhere in the world where invasive alligatorweed has become a problem, including in Australia, New Zealand, China and Thailand. The success of these introductions as a means of controlling Alternanthera philoxeroides has generally been good to excellent (UF/IFAS CAIP undated). The flea beetle, Agasicles hygrophila, was introduced in 1964 to combat alligatorweed which invades United States waterways from Virginia to southern Florida and along coast waterways to Texas and in California. The success of this program was so remarkable that the U.S. Army Corps of Engineers canceled all herbicide spraying against alligatorweed in Florida in 1968; three years after the beetles were introduced there!

 

Adult alligator weed flea beetles have a black head and thorax and yellow and black striped elytra (wing covers) covered with a waxy cuticle that gives it a shiny appearance).  A key distinguishing characteristic of adult members of the flea beetle family (Chrysomelidae) is the presence of greatly enlarged femora (the upper leg section) of the hind legs. Chrysomelids use these powerful hind legs to leap considerable distances if disturbed, thus earning the common name "flea beetle.
The larvae are black, up to 6 mm long when mature third instars; eggs are yellowish, 1.25 mm long and are laid in clusters on the undersides of leaves. Adults have greatly enlarged hind femora for jumping, hence the name flea beetle. Adult A. hygrophila range in size from 4 to 7 mm in length and approximately 2 mm wide..

This is an extreme specialist herbivore, feeding exclusively or nearly exclusively on the stems and, in particular, the leaves of alligatorweed. Both adult and larval forms feed on this weed, attacking the emergent (above the waterline) portions of the plant.  Impacts on native, non-target vegetation are likely to be similarly minimal. Research on A. hygrophila was conducted in Argentina before introduction into the U.S. At least 14 different plant species were examined for damaged caused by flea beetles. Results showed no damage and no beetles present on nearby non-target plants

 

Adults overwinter among the roots and stems of alligatorweed along the margins of waterways. Eggs are laid on the undersides of leaves. Larvae eat the leaves during their development, often leaving transparent windows of uneaten epidermis. Pupation takes place inside the hollow plant stems. The life cycle takes less than one month, and adults live about 48 days. Eggs hatch approximately 4 days after they are laid at temperatures ranging from 20-30°C. The larvae are initially pale gray, with the legs turning brown within a few hours of hatching. Succeeding instar larvae are pale gray with brown heads and legs, and the third (final) instar is almost black in color. These mature larvae burrow into and pupate in the hollow stems of the alligatorweed plant and emerge as adults through the holes in the stems.

The alligatorweed flea beetle is so successful that it is often used as the symbol of biological weed control. Within 4 years, alligatorweed was practically eliminated at the two northern Florida sites where the flea beetle was first introduced. The beetle is less effective in southern Florida and in northern areas of Alabama, Louisiana, Mississippi, and in North and South Carolina. Additional beetles from a colder region in Argentina were released in the Carolinas in 1979, apparently without success.

Cereal Leaf Beetle-Oulema melanopus.  This is an agricultural pest and biological control success story. The beetle is mostly blue-black in color, with an area of deep red just behind the head. The legs are dull orange. The most common host plants of the cereal leaf beetle are barley, oats, and wheat, but they are also found on rye, millet, rice, many types of wild grasses, and new corn shoots. The beetle has a history as a major crop pest in Europe, Asia, and parts of North Africa, but serious eradication efforts did not begin until the pest began to destroy oat fields in the United States in the 1960s. Insecticides were used without success, but when natural enemies of the beetle were discovered, imported, and released in affected fields, the cereal leaf beetle came under control.

                                                                                                  

                                                                                 Cereal Leaf Beetle.  Image Courtesy of entomart.be/contact.html

The cereal leaf beetle overwinters in fields of wild grasses, and as the weather warms in the spring it enters cultivated fields and deposits eggs. The larvae emerge and cover themselves with their own excreta in order to mimic the droppings of birds or other insects. They usually appear as shiny, wet lumps adhered to the surface of leaves. They gorge on the plants, then drop off and pupate in the soil for about 3 weeks, emerging full-grown to continue feeding on the plants. Both adult and larva prefer young plant shoots or areas of new growth on established plants. Damage from cereal leaf beetle is apparent when the tips of leaves turn white and the leaves develop white stripes or slits where the beetle has consumed a strip. A field with extensive damage will look frosted or whitewashed.

Parasitoids successfully employed against the cereal leaf beetle as agents of biological control include the parasitic wasps Diaparsis carinifer, Lemophagus curtus, and Tetrastichus julis, which attack larvae, and Anaphes flavipes, which is an egg parasitoid. Lady beetles eat the eggs and larvae.

FAMILY-COCCINELLIDAE-LADY BEETLES

 

           Members of this family are typically round to oval medium sized beetles with short capitate antennae.  They normally are brightly colored with or without spots and rarely have stripes.  Almost all ladybeetles are predatory in the adult and larval stages and most are quite host specific and therefore considered to be beneficial from the standpoint of biological control.

 

            

 

                                                                                                                        A typical ladybug shape with capitate antennae.

 

Mexican Bean Beetle, Epilachna varivestis.  This is a species of lady beetle which is a notorious agricultural pest. It is one of the few lady beetles that feed on plants rather than other insects. It is found throughout Mexico and the eastern United States, and is abundant in the wetter and more heavily irrigated areas west of the Rocky Mountains. It does not tolerate extremely dry areas.

                                                                                         

                                                                                                         Mexican Bean Beetle Adult and Larvae.

It is similar in appearance to other lady beetles, oval-shaped and bearing eight black spots on each elytron. Its overall color is quite variable, ranging from bright red to rusty brown to golden yellow. It is 6 or 7 millimeters long. The eggs are yellow, about 1.3 millimeters in length, and glued in clusters of up to 75 on the undersides of leaves. The larvae are usually yellow, spiny, and pill-shaped. Each is approximately 1.5 millimeters in length when first emerged, and grows up to one centimeter long before pupation. The larva attaches its anal segment to the underside of a leaf and hangs there to pupate.

The Mexican bean beetle feeds on beans and other legumes. It can be found on a great variety of bean plants, including common bean varieties (Phaseolus vulgaris), lima bean (Phaseolus lunatus), cowpea and azuki and mung beans (Vigna spp.), and soybean (Glycine max). It will also attack other legumes such as alfalfa (Medicago sativa) and various clovers (Trifolium spp.). Adult beetles may eat the fruits and flowers of the plants, but generally prefer the leaves. They eat the tender parenchyma of the leaves from the underside, leaving the upper epidermis intact. This gives the leaf a lacy, "skeletonized" appearance. The larvae also eat the leaves, and they do much more damage than the adults.

Adults emerge from dormancy in late spring, and each female lays several hundred eggs in clusters of 50 to 75 on bean plant leaves. The larvae are voracious feeders, and can inflict heavy damage on a field of bean plants during an infestation. After a few weeks of gorging on plants the larvae pupate in groups under the leaves. They winter as adults, and often travel long distances to find new fields.

Several types of insects show promise as biological pest control agents against the Mexican bean beetle, but insecticides are still routinely used in areas of high economic impact.                        

 

                                                                                                   Common Ladybugs Found in Biological Control of Various Pests

            

 

Coleomegilla maculate. This lady beetle, a North American native, is found throughout most of New York, southern Ontario, and southern New England and across the south to the mid-western states. It can be very common and is sometimes called the pink spotted lady beetle. C. maculata, is a medium-sized (about 5-6 mm), pink to red, oval beetle with six spots on each forewing. The area behind the head is often pink or yellowish with two large triangular black marks. C. maculata larvae are dark and alligator-like with three pairs of prominent legs, growing to 5-6 mm in length. Eggs are spindle shaped and small, about 1 mm long.

 

It is commonly found in wheat, sorghum, alfalfa, soybeans, cotton, potatoes, sweet corn (tassels may supply both pollen and small prey), peas, beans, cole crops, tomatoes, asparagus, apples and other crops attacking  aphids and other reported prey. C. maculata adults and larvae are important aphid predators but also prey on mites, insect eggs, and small larvae. Unlike most lady beetles, plant pollen may constitute up to 50% of the diet. Reported prey include pea, green peach, melon (cotton), cabbage, and potato aphids and greenbug; eggs of European corn borer, imported cabbageworm, fall webworm, and corn earworm; asparagus beetle, Mexican bean beetle, and Colorado potato beetle eggs and larvae. In trials to assess this lady beetle for control of Colorado potato beetle, it appeared to prefer aphids over beetle eggs and larvae.

 

Adults overwinter in large aggregations beneath leaf litter and stones along hedgerows or in protected sites along crop borders, especially those of fields planted to corn in the previous season. They emerge from early to mid-spring and disperse, often by walking along the ground, to seek prey and egg laying sites in nearby crops.

Female lady beetles may lay from 200 to more than 1,000 eggs over a one to three month period commencing in spring or early summer. Eggs are usually deposited near prey such as aphids, often in small clusters in protected sites on leaves and stems. Larvae grow from about 1 mm to 5-6 mm in length and may wander up to 12 m in search of prey. The larva attaches itself by the abdomen to a leaf or other surface to pupate. The pupal stage may last from 3 to 12 days depending on the temperature.

C. maculata adults may be found from April to late September and can be the most commonly observed lady beetles in corn, potatoes, and mixed crops. They may be especially abundant towards the end of the season when the adults aggregate in preparation for mating and winter hibernation. There are from two to five generations per year. Because pollen is an essential component of the diet of Coleomegilla, the planting or preservation of refuges, or inter-plantings, of early-flowering species with high pollen load may be beneficial especially to provide a food source during late spring before the buildup of aphids. Flowering dandelions, for example, have been recorded as a heavily used pollen source for dispersing adults in late spring potato fields. Adults of this beetle are commercially available for release in crops.

 

 

Right: Early spring congregation of C. maculata. Left. Whitney Cranshaw, Colorado State, Bugwood. Right. Images courtesy of J.Ogrodnick

 

          

Convergent ladybird beetle. Hippodamia convergens.  This beetle is one of the most notorious species occurring throughout most of North America. The larvae can daily consume their weight in aphids while the adult consumes up to 50 aphids a day.  In California and other states, adults (Figure 109) commonly are sold by nurseries, department stores, and home and garden centers.  Homeowners and even some cities and pest control technicians buy and release them for aphid control.  Although this species is quite effective in nature, the well-intentioned practice of mass-releasing adults of the convergent ladybird beetle for aphid control is generally considered of little or no value.

 

  The reasoning behind this statement is associated with the seasonal cycle of this beetle.  In the valleys of Southern California and other states, adult and larval beetles commonly are found feeding on aphids in the spring.  As the season progresses and the aphid populations begin to disappear, the behavior of these beetles changes drastically.  In late fall the adults fly to an elevation of about 5000 feet and follow the winds to the mountain passes.  At this time the adult beetles enter into a condition called reproductive diapause. While in this stage, the beetles congregate into huge clusters (sometimes many thousands per cluster) and hang on rocks and trees.  In diapause, the physiology of the beetle slows down.  They do not feed or lay eggs (Figure 109), but are capable of movement when prevailing temperatures are above 50 degrees (F). This condition allows the beetles to survive the winter without food and in freezing conditions.  In early spring they emerge from diapause and fly back to the valleys to lay eggs and resume their feeding on aphids.

               

    

            Adult convergent ladybird beetle.  Image courtesy of ARS.

 

The main environmental factor that triggers these beetles into and out of diapause is day length.  On a yearly cycle this is the only consistent factor in their environment.  On a given date at any time of the year the amount of daylight and darkness is always consistent.  Environmental conditions such as temperature on any given day of the year are inconsistent and, therefore, would be very unreliable as a triggering factor.  If temperature were used, it could be disastrous to the beetles.  A few hot days in December could trigger the beetles out of diapause, resulting in their flying back to the valleys where few, if any, aphids would be present.

 

Unfortunately, the beetles that are sold commercially are collected from the mountain passes while they still are in the diapausing condition. When they are sold in the spring, they may still be in diapause.  Of course they do not feed or reproduce.  If they are released in a yard and then emerge from diapause, they follow their natural instinct and fly away.

 

A consumer might be fooled into thinking he or she has a hard working bunch of ladybugs after such a release because a few individuals still remain in the yard.  However, these probably are members of the small percentage, which have been parasitized by wasps.  These unfortunate beetles never develop normally--they can't fly or feed well and do not reproduce.

 

The winter-collected beetles can be artificially triggered out of diapause by exposing them to the photoperiod (amount of daylight vs. darkness) normally present during the springtime.  Even when this is done, apparently the beetles still require an extended flight period prior to settling down to feed and reproduce.

 

A considerable amount of research has been conducted in the attempt to prevent the need for this flight period.  Scientists have turned the beetles in large tumblers over long time periods, attempting to simulate flight.  They have even tried gluing the elytra together to prevent this flight.  Nothing has been successful yet.

Cryptolaemus montrouzieri. Also known as the mealybug destroyer this beetle was imported into the United States in 1891 from Australia by one of the early biological control pioneers, Albert Koebele, to control citrus mealybug in California. Although C. montrouzieri initially devastated the citrus mealybug populations in citrus groves, it was unable to survive the winter except in coastal areas.  It has remained it those areas for over 100 years.  It remains active in groves in the coastal areas of California, interior scapes, and greenhouses. In addition, C. montrouzieri is released seasonally into inland citrus orchards. It has a limited feeding preference attacking citrus and closely related mealybugs and some soft scales, including hemispherical scale and its relatives. It is considered an important predator of citrus and long-tailed mealybug in greenhouses and interior plantscapes and is being introduced in a biocontrol program in the West Indies to control pink hibiscus mealybug.

                                                                            

                                                                            Mealybug Destroyer adult Images courtesy Dave Britton.

 

Mealybug Destroyer-Cryptolaemus montrouzieri.  This is a very small lady beetle with the adults measuring approximately 1/8th inch in length.  The head and thorax are orange-red with black elytra tipped in orange-red.  The larvae quite distinctly superficially resemble some mealy bugs with long filament radiating out from the body. This species was introduced into California from Australia in 1892 for control of mealy bugs. 

Adults are long lived (to 50 days) depositing 400 to 500 eggs.  Depending on temperature they pass through 3 larval instars in 12 to 17 days.  Pupation typically occurs in sheltered locations such as on stems or on greenhouse structures. Adult females lay eggs among the cottony egg sack of adult female mealy bugs. The larvae feed on mealy bug eggs, young crawlers, and the honeydew produced by mealy bugs.

C. montrouzieri is a voracious feeder of mealy bug in both the larval and adult stages - a single larva may consume up to 250 small mealy bugs. They are most effective when mealy bug populations are high, and repeated releases may be necessary if mealy bug populations are low. They require cottony egg masses for egg-laying (long-tailed mealy bugs do not have cottony egg masses). Although adults and young larvae prefer to feed on mealy bug eggs, older larvae will attack any mealy bug stage. Adults can fly and cover large areas to search for food. If mealy bugs are scarce, they will fly off in search of other related insects, e.g. aphids and soft scales, although reproduction is substantially greater on mealy bugs. Because C. montrouzieri cannot survive cold winters, they must be reintroduced into orchards where mealybugs were a problem the previous year in the early spring . The exception is moderate coastal regions.

Like other ladybeetles, C. montrouzieri tends to disperse when released. In indoor sites, keep windows and vents closed the day of release. Recent studies have shown that adults and larvae will spend more time searching a leaf for mealybugs if it has honeydew than if honeydew is absent.

Although mealybug destroyers will not persist after the mealybug population has been controlled in small greenhouse areas, in more complex interior areas where there are multiple infestation sites and alternate prey, they do persist. In Indianapolis, a single release of 100 beetles has persisted for over 5 years. If birds exist in interior-scapes, however, they will feed on adult beetles. It is important to remember that C. montrouzieri superficially resembles its prey, the mealybug. This can cause problems if large numbers of larvae are present on crops that are ready to be shipped or in indoor situations (such as malls) where the public may be unaware of the benefits of natural enemies.

Stethorus punctum .  Stethorus punctum is strictly a predator of plant-feeding mites, particularly the spider mites such as the European red mite and the two spotted spider mite, and especially the eggs. It is very commonly found in fruit orchards, strawberry fields, crops attacked by spider mites.

                                                                                                                

Adult Stethorus punctum. Images courtesy Weeden, C.R., A. M. Shelton, and M. P. Hoffman. Biological Control: A Guide to Natural Enemies in North America.

It overwinters in the adult stage beneath leaves and other organic matter under fruit trees and in other protected habitats near the orchard, such as fence rows or adjacent wooded areas. Adults begin to emerge at the tight cluster stage of apple development with peak emergence from the pink to bloom stage. Emergence is usually complete by the petal fall stage. Adults remain active in the orchard until September to late October. Egg laying occurs in most areas from May to mid-August. Eggs are laid close to the primary veins of the leaf and adhere tightly, with 95 percent on the undersurface of the leaf and 5 percent on the upper surface. The larva emerges after approximately 5 days. The larva passes through four larval stages in about 12 days, feeding on all stages of mites. The mature larva fastens itself to the leaf and remains in a motionless state for 24 to 48 hours before pupation which lasts about five days. The peak periods of larval activity are dependent upon mite populations. There are usually three overlapping generations per year. The average period from egg deposition to the appearance of the adult is 23 days, and the adults feed for an average of 25 days before beginning to lay eggs. Females lay 1 to 10 eggs per leaf depending on mite density.

S. punctum is one of the most important and frequent predators of spider mites in fruit orchards. Beetles consume all stages of mites; adults can consume 75 to 100 mites per day and large larvae can devour up to 75 miles per day, so they quickly lessen an outbreak of spider mites. Adults are very active when in fruit trees and if disturbed they will often fall to the ground. They are good fliers, and therefore tend to concentrate in areas of the orchard where mites are plentiful and disappear when the mite population becomes low. There must be 2-5 motile mites per leaf to keep S. pomatum in an orchard, and "pockets" of 8-10 mites per leaf are required for reproduction

Because adults overwinter in the leaf litter immediately surrounding the trunks of fruit trees, it is advisable not to disturb the area under the tree from November 1 to mid- to late April. Recent studies indicate the distribution of S. pomatum to be closely associated with the leaf litter distribution in the orchard.

Multicolored Asian Lady Bug-Harmonica axyridis.  This beetle has a number of color phases and patterns; hence the name multicolored.  It was initially introduced into the United States in 1918 for the control of a variety of insects; however, actual existing populations were not found until 1988 in Louisiana.  It now occurs in many areas and has been reintroduced on a number of occasions. Some of these introductions have been accidental on imported nursery stock and others have been on purpose as a beneficial insect.

                   

 

                       Multicolored Lady Bug.

The multicolored Asian lady beetle is similar to other familiar lady beetles commonly found throughout the United States. Like the familiar lady beetles, the multicolored Asian lady beetle feeds on insect pests in orchards and forests but may also occur on row crops and in gardens. The multicolored Asian lady beetle adults begin laying eggs on host plants in early spring. Eggs hatch in about three to five days, and larvae begin searching on plants for aphids and other soft-bodied arthropods on which to feed. Adults and larvae typically feed upon the same prey. Larvae molt four times, becoming larger after each molt, and enter an immobile pupal stage after the last molt.  After several days, the adult beetle emerges from the pupal case. Development time from egg to adult requires about 15-25 days depending on temperature and food availability. Later in the fall, near the time of killing frosts, the adult beetles seek shelter to spend the winter.

This variably colored and spotted lady beetle is an effective, natural control for harmful plant pests such as aphids, scale and other soft-bodied arthropods. Still, its tendency to overwinter in homes and other buildings, sometimes in large numbers, may make them a nuisance to many persons. If agitated or squashed, the beetles may exhibit a defensive reaction known as “reflex bleeding,” in which a yellow fluid with an unpleasant odor is released from leg joints. This reaction generally prevents predators, such a birds, from eating lady beetles. But in the home, the fluid may stain walls and fabrics. Multicolored Asian lady beetles have become a problem in some regions of the United States. It is probable that their introduction into new habitats in the United States freed these lady beetles from some natural population checks and balances that occur within their native Asian range. It is likely that these natural controls will catch up to the lady beetles in time and curtail their booming population. Additionally, a period of time may be required for checks and balances of our native lady beetles to adapt to this newcomer.

Lady beetles are not structure-damaging pests, unlike insects such as termites and carpenter ants. Lady beetles do not chew or bore holes in walls or eat carpet or furniture. They do not lay their eggs in homes. Multicolored Asian lady beetles are attracted to lighter colors: whites, grays, yellows. So, light-colored houses, especially on hillsides in forested areas, might serve as “homing beacons.” Once the lady beetles enter the walls of a building through cracks and crevices, they may or may not proceed to the interior of the building. Most stay in the wall spaces.  During warm days of late winter and early spring, overwintering beetles in a wall space may become active. In their search for an exit, they may enter the home's living areas and become a nuisance. Warmer temperatures or lighting in the living areas may attract these active beetles as they search for an exit. 

Preventing the lady beetles from entering is the best approach to keeping them from becoming a household nuisance in fall and winter. Caulking exterior cracks and crevices--before the lady beetles seek overwintering sites-- is the best way to keep them out. This will also keep out other unwanted insects such as wasps, and will save homeowners money on energy costs.

Lady beetles that enter wall spaces in the fall may remain there, without entering living areas, until they depart in spring to search for food. But some may become active on warm days in late winter or early spring and move into living areas.  Sweeping and vacuuming are effective methods for removing these lady beetles from living areas. Using insecticides indoors for control of the lady beetles is not typically recommended unless the infestation is very heavy, and professional pest control advice should be sought. Lady beetles that enter living areas are typically attracted to light. A trap for indoor use that uses light to attract lady beetles and other flying insects was developed by entomologist Louis Tedders (retired) and colleagues at the Southeastern Fruit and Tree Nut Research Laboratory, Agricultural Research Service, Byron, Ga. The insects become trapped in a removable bag. Use of insecticide is unnecessary. A patent application was filed, but a patent was not granted.

 

Coccinella septempunctata. Sevenspotted Lady Beetle.  The seven-spotted lady beetle, repeatedly introduced to North America from Europe for the biological control of aphids, was established in the early 1970s in New Jersey, apparently from an accidental introduction. It has since spread naturally or been introduced to many northeastern and north central states. C. septempunctata may be a more effective predator than some native lady beetle species, displacing them in some areas.

                                                                                           

                                                                                  Seven Spotted ladybird Beetle.  Image Courtesy J Ogrodnick.

These are comparatively large (7-8 mm) with a white or pale spot on either side of the head. The body is oval, and has a domed shape. The spot pattern is usually 1-4-2, black on the orange or red forewings. Lady beetle larvae are dark and alligator-like with three pairs of prominent legs, growing to 7-8 mm in length. Eggs are spindle shaped and small, about 1 mm long.

Reported prey include pea, cowpea, green peach, potato, corn leaf, melon aphids, and greenbug.  Adults overwinter in protected sites near the fields where they fed and reproduced. In spring, emerging beetles feed on aphids before laying eggs. Females may lay from 200 to more than 1,000 eggs over a one to three month period commencing in spring or early summer. Eggs are usually deposited near prey such as aphids, often in small clusters in protected sites on leaves and stems. The eggs are small (about 1 mm) and spindle-shaped.

C. septempunctata larvae grow from about 1 mm to 4-7 mm in length over a 10 to 30 day period depending on the supply of aphids. Large larvae may travel up to 12 m in search of prey. A second generation may appear about a month later. The pupal stage may last from three to 12 days depending on the temperature.

In the northeastern United States, there are one to two generations per year before the adults enter winter hibernation. Development from egg to adult may take only two to three weeks, and adults, most abundant in mid- to late summer, live for weeks or months, depending on the location, availability of prey, and time of year.

C. septempunctata is spreading to new areas each season. Conservation can best be accomplished by following integrated pest management guidelines as outlined in the tutorial of this guide. Tolerance to some pesticides at recommended application rates is likely. Overwintering adults may be less susceptible than active adults and larvae. This species has been mass reared, but at this time is not commercially available.

 

Twice Stabbed Lady Bug. Chilocorus stigma.  Nearly all species in the genus Chilocorus are predaceous on scale insects, although some will accept aphids or adelgids as prey (Gordon 1985). Most species are tropical, but seven species of Chilocorus are native to the United States. Two species, C. kuwanae and C. bipustulatus, have been introduced for biological control. However, the native Chilocorus stigma is the only one that occurs in most of the United States. It does not occur west of the Sierra Nevada. C. stigma is synonymous with C. bivulnerus Mulsant.

C. stigma adults appear shiny black with a large red spot in the center of each elytron. Adults average 3.75-5.0 mm in length. The body is completely black except for the abdomen, which is yellow or red. A few other native Chilocorus species closely resemble C. stigma, but for the most part they are found in California where C. stigma does not occur. The introduced species C. kuwanae appears similar but can be distinguished by the appearance of the spot on its wings (see page on C. kuwanae). Larvae are black or grey and spiny in appearance. Eggs are small (about 1.1 mm long), orange, and laid on their sides either singly or in small group.                                                                                                                                                                                                                                                                 Twice Stabbed Lady Bug. Image Courtesy Rayanne Lehman, Department Agriculture.                                                                                                                                                                                         C. stigma completes two generations in the northern U.S. In Florida, it can complete several generations a year. In cold areas, overwintering adults become active in early spring (April or May). Mating begins shortly and continues for about three weeks. Eggs are laid soon afterwards. Larvae emerge in late May and undergo four instars before pupating.  In New York State, the overwintering adults continue to feed through June and early July, after first generation larvae have hatched. First generation adults mature in early to mid July. Mating and oviposition continue as before, and second generation larvae are observed beginning in mid July through early August. Adults emerge in midsummer and overwinter in ground litter. Chilocorus species typically prefer arboreal habitats. They have been identified as beneficial natural enemies in orchards, tree plantations, and forests. In Michigan, C. stigma is often found in Christmas tree plantations and forests where scale insect infestations are found.

 

Currently C. stigma is not commercially available in the United States. Developing an efficient and productive rearing method for C. stigma could be an important contribution to biological control or integrated pest management programs.

 

DERMESTIDAE-CARPET BEETLES

This is a relatively small family of small to minute beetles, which are sometimes referred to as skin beetles or buffalo bugs.  The bodies of the adults are mainly oval and convex in shape and covered with dense hair or scales.  The antennae are clubbed and the head is somewhat retracted into the thorax.  Many have a distinct patterning on the back of the elytra.  Adults of many are pollen feeders and can be collected in flower heads.  As with most stored product pests, this beetle is worldwide in distribution, having been shipped around the world in various contaminated products.

There are approximately 500 to 700 species worldwide. They can range in size from 1–12 mm

skeletons. Some dermestid species, commonly called "bow bugs," infest violin cases, feeding on the bow hair. Dermestids have a variety of habits; most genera are scavengers that feed on dry animal or plant material such as skin or pollen, animal hair, feathers, dead insects and natural fibers. Members of Dermestes are found in animal carcasses, while others may be found in mammal, bird, bee, or wasp nests. Thaumaglossa only lives in the egg cases of mantids, while Trogoderma species are pests of grain.

These beetles are significant in forensic entomology. Some species are known to be associated with decaying carcasses which help with criminal investigations. Also some species are pests (urban entomology) and can cause millions of dollars in damage to natural fibers in homes and to major businesses. They are used in taxidermy and natural history museums to clean animal skeletons.

 

                                                                            

 

                                                                                                                                                          

                                                                                                                                  Dermestid Beetle Larvae  Being Used to Clean A Human Image Courtesy of Skimsta.

Forensic Entomology. Dermestes maculatus, hide beetles and other insects have the potential to offer investigators an estimation of the time since death in homicide or questionable cases. Similar to the use of flies in forensic entomology, the arrival of D. maculatus to carrion occurs in a predictable succession. Adult D. maculatus beetles generally arrive 5 to 11 days after death.  In an attempt to refine this relatively wide range, recent research has repeated arthropod succession studies. These studies are applied to estimate the arrival of various species of Dermestidae after death. Development for Dermestids is temperature dependent, and the optimal temperature for D. maculatus is 30˚C. Development data is normalized using Accumulated Degree Days.  Dermestids can also be used in cases involving entomotoxicology, where feces and shed larval skins can be analyzed for toxins.

Entomotoxicology. In forensic entomology, entomotoxicology is the analysis of toxins in arthropods (mainly flies and beetles) that feed on carrion. Using arthropods in a corpse or at a crime scene, investigators can determine whether toxins were present in a body at the time of death. This technique is a major advance in forensics; previously, such determinations were impossible in the case of severely decomposed bodies devoid of intoxicated tissue and bodily fluids. Ongoing research into the effects of toxins on arthropod development has also allowed better estimations of postmortem intervals.

Entomological samples are analyzed in similar standards to human tissue samples. Once the insects have been removed from the body, or the crime scene, they are washed with deionized or tap water. The specimens are then frozen for storage at a temperature ranging from -20°C to 4°C until they are needed for analyses. Specimens are prepared for analysis in a variety of ways. They differ based upon the substance that is in question.

To prepare for analysis of inorganic substances, the arthropods are taken out of storage, washed, and then dried to insure the removal of any foreign human fluids. The arthropods are then crushed and stored in a porcelain crucible at a constant 650°C for 24 hours. The resulting ash has a high concentration of metals, which are then analyzed by acid digestion using 70% HNO₃ (nitric acid).

For preparation of organic substances, the specimens are first washed and dried. Between 1–10 grams of larvae are finely cut and an internal standard solution is added. The specimens are then homogenized, in a 0.9% saline solution, and centrifuged. Chitinous samples of organic substances are prepared by adding an internal standard solution to finely chopped puparial casings and placing the sample in test tubes. Strong acids or bases break down the chitonous exoskeleton to release any toxins. Hydrochloric acid is added to the test tube, and the sample is allowed to extract overnight at a temperature of 65°C. The acid solution is then removed and the organic substances are fully available for further analyses.

Analytical techniques differ for organic and inorganic substances. Inorganic substances are analyzed using inductively coupled plasma (ICP), atomic emission spectroscopy (AES), and flame atomic absorption spectrometry (FAAS). ICP is primarily used when the concentration of the substance is relatively low. Organic substances are analyzed by the screening test, radioimmunoassay (RIA), and by confirmation tests which include chromatography techniques including thin layer chromatography and gas chromatography. Liquid-liquid extraction (LLE) and solid phase extraction (SPE) are the analytical techniques of choice when dealing with substances in an aqueous phase.

Drugs can have a variety of effects on development rates of arthropods. Morphine, heroin, cocaine, and methamphetamine are commonly involved in cases where forensic entomology is used. The stages of growth for insects provide a basis for determining a cause in altered cycles in a specific species. An altered stage in development can often indicate toxins in the carrion on which the insects are feeding. Beetles (Order: Coleoptera) and beetle feces are often used in entomotoxicology, but the presence of toxins is often the result of the beetles’ feeding on fly larvae that have been feeding on the carrion containing toxic substances. Flies (Order: Diptera) are the most commonly used insect in entomotoxicology.

Through the study of Sarcophaga (Curranea) tibialis (fleshflies) larvae, barbiturates were found to increase the length of the larval stage of the fly, which will ultimately cause an increase in the time it takes to reach the stage of pupation.  Morphine and heroin were both believed to slow down the rate of fly development.  However, closer examination of the effects of heroin on fly development has shown that it actually speeds up larval growth and then decreases the development rate of the pupal stage. This actually increases the overall timing of development from egg to adult. Research of Lucilia sericata (blowfly), reared on various concentrations of morphine injected meat, found higher concentrations of morphine in shed pupal casings than in adults.  Cocaine and methamphetamine also accelerate the rate of fly development.

Some effects depend on the concentration of the toxin while others simply depend on its presence. For example, cocaine (at the lethal dose) causes larvae to “develop more rapidly 36 (to 76) hours after hatching”.  The amount of growth depends on the concentration of cocaine in the area being fed upon. The amount of methamphetamine, on the other hand, affects the rate of pupal development. A lethal dose of methamphetamine increases larval development through approximately the first two days and afterwards the rate drops if exposure remains at the median lethal dosage. The presence of methamphetamine was also found to cause a decrease in the maximum length of the larvae.

Along with changes in development rates, extended periods of insect feeding refrain and variation in the size of the insect during any stage of development, can also indicate the presence of toxic substances in the insect’s food source.

Examples. Since it was first demonstrated that the ability of toxins to be recovered from maggots feeding on human remains in 1980, the use of entomotoxicology in investigations has made an emergence into the field of forensic entomology. An example of one such case involved the discovery of a 22 year old female with a history of suicide attempts that was found 14 days after her death. Due to the body’s advanced stage of decomposition, no organ or tissue samples were viable to screen for toxins. Through gas chromatography (GC) and thin-layer chromatography (TLC) analysis of Cochliomyia macellaria (blowfly) larvae found feeding on the woman’s body, phenobarbital was detected and perceived to have been in the woman’s system upon death.

Two months after death a liquid chromatography analysis on organ tissue and Calliphoridae larvae found at the scene revealed the existence of five prescription medications. Triazolam, however, was only detected in the analysis of maggots and not in organ tissue samples. Comparative research showed increased sensitivity of toxicological analysis of Diptera samples over decomposed body tissues. A similar case involved the discovery of the remains of a 29 year old known to abuse drugs, last seen alive five months prior. Through the use of GC and GC-MS techniques, Nolte and his partners discovered the presence of cocaine in decomposed muscle tissue and in maggots found on the body. However, due to the severity of decomposition of the muscle tissue, more suitable drug samples (devoid of decomposition byproducts) were reared from the maggots.

In some cases these techniques can even be used to determine of origin of a corpse.  There was the case of a young woman found severely decomposed in Inkoo, Finland. Diptera larvae recovered from the body were reared to adulthood and found to contain low levels of mercury, indicating that the woman came from an area of comparatively low mercury pollution. This assumption was proven correct once the woman was identified and found to have been a student in Turku, Finland. This case demonstrated the ability of toxicological analysis to help determine origin.  This case applied Nuorteva’s research involving mercury and its affect on maggots. Through experimentation, it was determined that maggots (fed on fish containing mercury) possessed levels of mercury in their tissue of even greater concentration than in the tissue of the fish. Nuorteva also discovered that the presence of mercury in the maggots systems hindered their ability to enter into the pupal stage.

Not only are tissues from maggots used to detect toxins, shed casings and insect feces have also been used to detect and identify toxins present in corpses upon death. An instance of this finding was demonstrated by Edward McDonough, a medical examiner in Connecticut. A mummified corpse of a middle-aged woman was found inside of her home. Prescription medicine bottles were found with labels identifying the following drugs: ampicillin, Ceclor, doxycyline, erythromycin, Elavil, Lomotil, pentazocine, and Tylenol 3. McDonough performed toxicological analyses on stomach contents and dried sections of brain and found lethal levels of amitriptyline and nortriptyline. Insect feces, shed pupal cases of Megaselia scalaris (Diptera: Phoridae), and shed larval skins of Dermestes maculates were gathered from the corpse at the scene. McDonough sent these to an FBI lab which broke down the complex structures of the samples using strong acids and bases and freed the toxins for analysis. The cast pupal cases and larval skins were also found to contain amitriptyline and nortriptyline. Larger concentrations were discovered in the pupal cases because phorid flies prefer to feed on softer tissues. The hide beetle larval skins revealed lower concentrations of the drugs because these beetles prefer to feed on dry, mummified bodies. The use of pupal cases and larval skins allows for investigators to detect toxins in a body years after death.

Black carpet beetles- Attagenus unicolor. Adult black carpet beetles are oval and appear shiny-black with brownish legs. They vary in body length from 1/8 to 3/16 inch. Larvae, frequently staying hidden when feeding, are golden to dark brown and are about 1/2-inch long. The body resembles an elongated carrot or cigar with a long brush of bristles at the tail end. 

 

Black carpet beetle larva and adult.   Image courtesy Clemson University and USDA.

Life Cycle. The larvae eat almost any type of animal product such as leather, wool, silk, feathers, hair, dried meat, dead insects, and even dried plant material. The black carpet beetle is a pest in kitchen cupboards, as well as in woolen carpets or clothes storage areas. The tiny pearly-white egg can be deposited in the lint around baseboards, in the ductwork of hot-air furnace systems, on wool clothing in storage, and in similar protected locations. The egg hatches in 6 to 11 days in warm weather, but may require an additional 5 to 16 days under cooler conditions.

The newly hatched larvae scavenge for food (they will eat dander, hair, and other small bits of food high in protein), avoid light, and move so slowly that they appear to be gliding. At room temperature, the larval life span ranges from 258 to 639 days. This variation is due largely to fluctuations in temperature, food quality, and relative humidity. The larvae may molt 5 to 11 times, and up to 20 times when conditions are unfavorable. The larval skins often are mistaken for the larvae themselves. The larvae pupate in the last larval skin, and the pupal period may extend from 6 to 24 days. The beetles may remain in the partially shed pupal skin from 2 to 20 days before emerging. Black carpet beetles usually overwinter in the larval stage.

Adults may live from 2 weeks to several months, but never damage household goods in this stage. Unlike the larvae, they are attracted to light. They are active and often can be found around windows and outdoors on flowers, eating the pollen. The females commence egg laying on the larval food materials or in dark secluded places less than one week after emergence. A female can lay from 42 to 114 eggs, and averages around 50; she generally dies a few days after oviposition.

The adults are attracted to flowers, and in the spring of the year they may fly into the house. The larvae may wander from the nest into the attic and other parts of the house. At times, birds and other animals die in chimneys and elsewhere in the house and their carcasses become a source of food for the larvae. Very often, the black carpet beetles are brought into the house with old woolens and carpeting. Sometimes the black carpet beetles are introduced into a dwelling in stored products such as dried dog food.

Control. It is not uncommon to find one or two black carpet beetles in a house. An occasional black carpet beetle larva probably is not an indication of a serious problem; however, if you regularly encounter large numbers of larvae or adults, find the source of the infestation and institute the following control measures.

Successful control depends on locating the source of the infestation. It may be a woolen toy stored in the basement, soiled woolen socks in boots, a felt hat on a shelf, carcasses of birds or other animals, dead insects in walls or attic, bits of dried dog food, or similar materials. If you find the infested material, either clean it or destroy the item.

Where the beetles are widespread and no point source of infestation is found, you may apply one of the various insecticides and chemical formulations that are available for carpet beetle control. Diatomaceous earth and silica aerogel that cause insects to lose moisture are known as desiccants. Apply them as a dust to cracks and crevices or inject them into wall voids. They are only effective if they remain dry, and work best where water sources are eliminated or reduced. You can apply synthetic pyrethroids as a water-based spray. When injected into dark crevices, the materials have a longer period of efficacy because they are not in direct sunlight. Crevices where lint, hair, and food particles have accumulated are places likely to be infested by carpet beetles.

Varied Carpet Beetle-Anthrenus verbasci.  Las instar larvae of A. verbasci are roughly 4-5 mm in length. The body is covered in a pattern of alternating light- and dark-brown stripes. The body is usually wider at the back than at the front and also bears 3 pairs of hair tufts along its rear abdomen that can be used for self-defense.

 

Larvae of varied carpet beetle. Image courtesy of André Karwath aka 

Adult varied carpet beetles range from 1.7 to 3.5 mm in length. Their dorsal surface has scales of two colors, whitish and yellowish-brown. White scales are condensed along the lateral margins of the pronotum. In addition, their antennae are 11-segmented with a club of 3 segments.

                                                                                                                 

Adult of varied carpet beetle. Image courtesy of André Karwath aka 

The varied carpet beetle has an unusual long life cycle for an insect, developing from larvae to adult in 1-3 years, depending on the environmental conditions.  Larvae hatch from eggs in the spring and early summer, often in the nests of birds or around stored fabrics.  Larvae feed on natural fibers throughout their development, eventually diapausing prior to pupation into the adult stage. The length of diapause appears to depend on environmental factors, with photoperiod the most common factor that trigger them from this condition. Adults emerge between late May and early August feeding mainly on the pollen. During this period, mating occurs, eggs are laid, and the cycle begins anew. Among the natural predators of A. verbasci, one of the most well-studied is the parasitoid wasp Laelus pedatus. Upon discovering an A. verbasci larva, a female wasp will land on the larva’s dorsal side and attempt to line up its long, stinger-like ovipositor for a paralyzing blow to the thorax. In response, the larva will erect long hairs on their abdomen and attempt to brush these hairs against the encroaching wasp. The hairs detach and stick to the wasp on contact, presumably causing some sort of irritation. Evidently, such irritation is not enough to deter an attack on A. verbasci larvae, as the vast majority of attacks are successful. Such a defense, however, has been shown to be effective for the closely related species Anthrenus flavipes, which has slightly longer hairs than A. verbasci^.

After a single successful sting, the beetle is permanently paralyzed. The entire process from landing to complete paralysis lasts approximately 40 seconds. Interestingly, L. pedatus does not lay eggs immediately after the beetle is paralyzed, waiting as long as 24 hours before oviposition. During this time, she grooms herself, removing any hairs that might have stuck to her during the attack. During this lengthy process she appears to monitor the larva’s state of paralysis by repeatedly biting it and monitoring its reaction. Once sufficiently clear of hairs, the wasp creates a bare patch on the larva’s abdomen and lays 2-4 eggs. Eggs hatch in 3-4 days and the larvae feed on the beetle for 3-7 days, eventually killing the host. They then spin cocoons near the empty shell of the host, emerging some time later as an adult wasp.

The larvae of A. verbasci are a common household pest. Adult beetles usually lay their eggs in air ducts, in closets, under furniture, or under baseboards . Once hatched and until they pupate into adults, the larvae hide in dark, undisturbed areas and feed on organic material. The larvae are thus responsible for the damage of various items, such as furniture, clothing, blankets, furs, and carpets. Collections of specimens, especially of insects, are also vulnerable to attack, making A. verbasci a common pest in museums.  Infestations can be prevented by regular vacuum cleaning, dry cleaning or airing clothing outside, using moth balls in cedar chest or other enclosed containers, and removing abandoned bird and insect nests attached to the building. Signs of an infestation include the presence of damaged articles, molted larval skins in dark areas, and an abundance of adult beetles near windows.

 

Furniture Carpet Beetles-Anthrenus flavipes. Adult furniture carpet beetles are about 1/16 to 1/8-inch long, nearly round and whitish checkered with black spots, each outlined with yellowish orange scales. These scales are broadly oval and two times or less as long as they are broad. The legs have yellow scales. The bottom surface of the body is white. Color patterns vary. Larvae, frequently crawling rapidly, are about 1/4-inch, elongated, oval, and are covered thickly with brownish hair. Larvae: The larval stage of the furniture carpet beetle is responsible for causing damage. The larva of the common carpet beetle, Anthrenus scrophulariae, is difficult to distinguish from that of the furniture carpet beetle. One way to distinguish the furniture carpet beetle from the common carpet beetle is to look for the presence of a long pencil of hairs at the end of the body that continually vibrates which is indicative of the furniture carpet beetle. Larval color is dependent on the color of the food substrate. A good quality hand lens or microscope is necessary to see these characters.

 

Adult and Larvae of furniture carpet beetle. Image courtesy Clemson University

The furniture carpet beetle is a common pest of upholstered furniture. Like other species of carpet beetles, it is able to digest keratin, the principal protein found in animal hair and feathers. Furniture carpet beetles are found on furniture where they feed on hair, padding, and upholstery. Other food sources include carpet, fur, horns, and silk. Cotton, linen, rayon, and jute may be attacked when stained with animal body oils or excreta. The current practice of encasing furniture horsehair in a green rubber coating does not protect horsehair from infestation. Dried insect specimens such as those found in insect collections are also devoured.

The furniture carpet beetle is a cosmopolitan pest and is most destructive in warmer parts of the world. In the United States, the furniture carpet beetle is primarily a pest of the southern states but may also be associated with heated buildings in northern states.

 

The furniture carpet beetle undergoes complete metamorphosis, passing through the egg, larva, pupa, and adult stages. The complete life cycle requires four to 12 months depending upon the temperature. The larval stage of the furniture carpet beetle is responsible for causing damage. The number of larval instars may vary from six to 12 and requires two to three months before pupation occurs. 
The larvae of the furniture carpet beetle pupate in their last larval skin and are white in color. Pupation occurs on or near the larval food source. The pupal stage lasts an average of two to three weeks depending on temperature.  Adults may be found feeding on the pollen of flowers, but do not cause damage to the flower. The adult furniture carpet beetle has a life span of 30 to 60 days.

 

The furniture carpet beetle is capable of significant damage if infestations are undetected. It can destroy upholstered furniture by devouring both the padding and the covering. The furniture carpet beetle consumes any suitable food source rendering products unusable or aesthetically unappealing. Additionally, individuals in close association with infested items may suffer allergic reactions as a result of exposure to beetle fragments, cast skins, or dusts.

 

Furniture carpet beetles can be detected by a close and thorough inspection of susceptible household goods. The presence of any furniture carpet beetles could warrant corrective actions. Depending upon the value of the infested items, some may choose to discard the items while others may choose control options in an effort to salvage the goods. Careful inspection is the first step in controlling furniture carpet beetle infestations. All susceptible materials must be inspected for the presence of larvae, their cast skins, and damage. The adults may also be observed emerging during the warm summer months. Proper sanitation cannot be overemphasized for controlling the furniture carpet beetle. An important tool that is used in sanitation is the vacuum cleaner. A vacuum can be used to remove pet hair, human hair, and loose fibers from furnishings, carpets, and clothes. Steam cleaners are more effective when cleaning infested items since hot soapy water kills all stages of the furniture carpet beetle. Infested clothes and furs should be professionally dry-cleaned. Cold storage treatments may also be effective for infested items such as furs.

As with many of the other species of carpet beetles the furniture carpet beetles are common pests of fabrics and furs.  These are much more common than the so-called clothes moths.  Cedar chests and mothballs can be an effective means of control.  Cedar has oils that will repel these beetles.  Mothballs are a fumigant and must be used in an airtight container.  If nothing else is available it is useful to store susceptible garments in a clean condition.  Carpet beetle larvae cannot complete development on clean wool.  In order for these beetles to develop on wool, it must be contaminated with body oils, food stains or other materials.

 Larder or Hide Beetle- Dermestes maculates.  The larder beetle is a very common and widespread household insect pest.  The insect's name comes from it's presence in dried, cured meats stored at room temperature prior to refrigeration.  Today, larder beetles may be a pest in stored foods and other items of high protein content.  Larder beetles outdoors are valuable “recyclers” that play an important role in the breakdown and recycling of animal protein.

The larder beetle adult is slightly longer than 1/4th inch.  It is roundly oval and dark brown to black with a characteristic light colored band running across the body.   This light band contains 6 more or less prominent dark spots.  Larder beetle larvae are up to 1/2 inch long.  They are tapered in shape and covered with sparse, stiff hair.   There are 2 upward curved spines on the posterior end. 

 

Larder Beetle Adult.

Both the larvae and adults feed on items such as fur, hair, hides and occasionally stored products such as dried fish, pet food and cheese.  In the house, however, the most likely source is dead insects or other animals (box elder bugs, attic flies, mice, etc.) that have accumulated inside walls or attics.

If a source of larder beetles can be determined than control can be achieved by discarding or cleaning infested woolens, feathers, furs, hides and so forth.  However, in the more typical, general infestation the source is probably the dead insects within the inner wall spaces and removal or sanitation is not practical.  Cleaning is still recommended.  Thoroughly vacuum clean cracks and crevices in the areas where larder beetles are found.

Forensic Entomology. The hide beetles also have the potential to offer investigators an estimation of the time since death in homicide or questionable cases. Similar to the use of flies in forensic entomology, the arrival of D. maculatus to carrion occurs in a predictable succession. Adult D. maculatus beetles generally arrive 5 to 11 days after death. In an attempt to refine this relatively wide range, recent research has repeated arthropod succession studies. These studies are applied to estimate the arrival of various species of Dermestidae after death. Development for Dermestids is temperature dependent, and the optimal temperature for D. maculatus is 30˚C. Development data is normalized using Accumulated Degree Days.  Dermestids can also be used in cases involving entomotoxicology, where feces and shed larval skins can be analyzed for toxins.

Khapra Beetle-Trogoderma granarium. This is  considered to be one of the world's most destructive pests of grain products and seeds, probably originated from regions now including India and Bangladesh, but has since spread to other areas including northern and eastern Africa, southern Europe and the Mediterranean region, the Mideast, and east into Asia. This pest thrives in warm, dry climates. Populations build rapidly in a short time under hot, dry conditions, but can survive in colder climates in heated situations such as warehouses, food plants and grain storages. The beetle cannot fly, and is therefore spread mainly by commerce and trade. The problem of preventing the beetle's spread is compounded by its ability to survive for several years with little food, and its habit of hiding in cracks, crevices and even behind paint scales or rust flakes. If left uncontrolled, the insect can make the surface of grain storage appear alive with crawling larvae. This species is a considered to be a dirty feeder, breaking or powdering more kernels than it consumes. They not only consume the grain, but may also contaminate it with body parts and setae which are known to cause adult and especially infant gastrointestinal irritation.

In addition to the obvious grain and stored product hosts, the beetle has been found in many locations that would not be obvious food sources, unless one realizes that the insect is by nature an omnivorous protein scavenger. It has been found in the seams and ears of burlap bags and wrappers, in baled crepe rubber, automobiles, steel wire, books, corrugated boxes (glue), bags of bolts, and even soiled linen and priceless oil paintings. It is frequently intercepted on obvious food products such as rice, peanuts, dried animal skins, as well as its preferred natural foods such as wheat and malted barley. Such infestations may result from the storage of the product in infested warehouses, by transportation in infested conveyances, or from reuse of sacks or packaging previously used to hold material infested by khapra beetle.

Detection may be accomplished by trapping or visual inspection. A khapra beetle trap developed by the USDA is commercially available. When using traps, be aware that a trap will only indicate that the species is present if trapped, but that negative trapping results shall never be used as absolute proof that the insect is not present. Inspecting for khapra beetle is difficult and meticulous due to the small size of the insect, its habits, and the difficulty of identifying small or damaged specimens. High risk areas that should be checked first include: 1) cracks in walls and floors 2) behind loose paint or rust 3) along pallet, and the end-grain of pallet wood 4) seams and ears of burlap bags 5) low light areas 6) trash from cleaning equipment, and the equipment itself. Low risk areas for inspection include: 1) well-lighted areas 2) areas of dampness, moisture, or where debris is mouldy 3) areas that are oily, such as floors. Vacuum cleaners can be used by inspectors to assist the inspector in drawing cast skins or dead adults out of cracks and crevices, and to pick up debris. Vacuum cleaner filters must be changed between inspection locations.

The classic telltale sign of a khapra beetle infestation is the presence of cast skins and larvae. The larvae are yellowish to golden brown (see picture below). They are clothed with fine setae, and there are tufts of barbed setae on each side of the terminal abdominal segments. Adults are oval shaped, brown to blackish, and with indistinct lighter brown patterns on the elytra. They may appear slightly hairy on top under a microscope. These hairs may trap dust, giving a dirty appearance. In older adult specimens the hairs may be rubbed off. Mature larvae are about one-quarter inch long, and adult females are about one-eighth inch long with males somewhat smaller. They pass through 4-7 molts during the larval stage, resulting in numerous cast skins. Adults are short-lived, persisting only for one to two weeks, but only for a few days at temperatures over 100°F. Adult activity is seldom noticed. They are more active during midday if the light is subdued, and prefer to avoid the light until they are of older age. Dead adults are not often found since they may be cannibalized by larvae, leaving only fragmentary remains for identification. Mating occurs almost immediately after adult emergence, with oviposition for one to six days following and the female laying up to 80 eggs. Eggs hatch in five to seven days. Larval development may occur in four weeks, but under cooler temperatures, crowding, poor food quality, or frass build-up, the larvae may enter a quiescent condition (diapause). They may persist for months, even as long as one to three years with little or no food in this diapause-like condition. Quiescent larvae may aggregate in large numbers in cracks or other hiding places. They may periodically wander in search of food, but then return to hiding for extended periods.

Khaphra Beetle Adult and Larvae.  Image Courtesy USDA.

Fumigation using methyl bromide is the treatment of choice. Because of khapra beetle's habit of hiding in cracks and crevices and infesting porous block, the entire structure, in addition to its contents, must be fumigated. Typically, the building is covered by tarpaulin and the fumigant is pumped in at an approved rate, typically six to nine pounds per thousand cubic feet, depending upon temperature. The process may take several hours, depending on the size of the building and the strict safety precautions required. The future for the continued use of methyl bromide fumigation for khapra beetle is uncertain at this time.

                                                                                                                                  Dermestids and Insect Collections.

As most entomologists know one of the favored foods of the larvae of many of the dermestid species is dead insects.  If left alone insect collections quickly attract the adult beetles that deposit their eggs in or around collection.  Once hatched over time the larvae will quickly demolish the infested collection.  The key to prevention is to keep insects in a well-built beetle proof box, periodic inspection and occasional fumigation with moth balls.

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                                                                                                                       Insect collection with dermestid damage.

1.     Leaf beetles have capitate antennae while the ladybugs have filiform antennae.  In addition the leaf beetles exhibit a variety of shapes while the ladybugs are slightly oval to round in shape.

2.     The adults flea beetles are quite active and readily feed on the leaves of a variety of plants (including crops), with typical damage consisting of small holes.

3.     The Colorado potato beetle is one of the exceptions to the generalization that almost all our major agricultural pests are those that have been introduced from other countries. 

4.     The bacterium that causes bacterial wilt overwinters in the gut of some of the striped cucumber beetles. When beetles become active in the spring and begin feeding, they spread the bacterium either through their feces or from contaminated mouthparts.

5.     Larval convergent ladybird beetles overwinter is in the mountain in a condition called reproductive diapauses.

6.     The larvae of the mealybug destroyer look very similar to a mealy bug.

7.     Dermestid adults are used to clean skulls and bones for mounts and other displays

8.     Both the larvae and adults of the larder beetlefeed on items such as fur, hair, hides and occasionally stored products such as dried fish, pet food and cheese.