Chapter 8. Hemiptera-True Bugs

The general public uses the term “bug” to refer to any of a variety of critters.  Occasionally scientists use this term in combination with other words to refer to insects from orders other than Hemiptera (e.g. lightning bugs, water bug, mealybugs).  When used alone by entomologists, this term refers to insects from the order Hemiptera.  The term 'true bugs' is also sometimes used to also distinguish insects of this order.

 

One characteristic of this order is piercing-sucking type mouthparts (Figure 30-arrow).  In this case the mandibles and maxillae have evolved into elongated, needle-like structures for piercing the host and sucking its juices.  In addition this beak rises from the front of the compound eyes on the head.  This latter characteristic is often used to distinguish the Hemiptera from the closely related order of the Homoptera that also possess piercing sucking beaks. In the Homoptera the beaks arise from the back of the head behind the eyes.

 

Another unique characteristic of Hemiptera is the structure of the front pair of wings.  In most Hemiptera the basal half (half closest to where the wing attaches to the body) of the front wing is thickened and leathery (arrow), while the proximal half (half furthest away from the point of attachment) is thin and membranous.  The derivation of the word Hemiptera refers to this structure (hemi = half, ptera = wing). 

 

As with other orders of insects many families have a characteristic appearance and this alone can be used for family identification.  This is especially true in the smaller families or even some of the larger families where there is not that much variation in overall appearance. For example there is nothing else that looks like a giant water bug, bed bug or water strider.  On the other hand in some of the larger families there is quite a bit of variation in overall appearance or in some cases the overall appearance is quite similar to other families in the order.  In these cases a closer look at the insect may be needed to determine family level.  One commonly used characteristic is the shape and structure of the hemelytra.

 

A true bug.  Note the elongated beak (piercing-sucking mouthparts) that originates or is attached in front of the compound eyes. Image Courtesy of University of Sao Paulo.

 

 

  Hemelytron of a true bug.  Note the leathery (arrow) and membranous (arrow) parts of the wing. 

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The shape of the legs is also useful in determining family level in the Hemiptera.  A common leg type in this order is referred to as raptorial front legs which are often found in predatory insects. With a raptorial front leg the femur or middle section (arrow) is enlarged (Figure 32).  This can be determined by comparing this section with the femur of the middle (arrow) or hind legs.  With predatory insects the front legs are often used to capture and hold prey.  As a result more strength (hence musculature) is needed to accomplish this task.  Correspondingly, a larger leg is needed to house the musculature.

 

 

A true bug with raptorial front legs characterized by swollen femur when compared to femur of middle leg.  Image courtesy of Troy’s Photo Gallery.

 

Aquatic Hemiptera

 

Many of the true bugs are aquatic.  In most cases they are predatory on other insects, but some of the larger species feed on small fish, frogs, and even small mammals such as mice.  One of the easiest means of identifying an aquatic true bug is by the presence of tiny hair-like antennae which are hidden beneath ridges in the front of the head. Terrestrial bug or even semi-aquatic bug possess well-developed antennae that are readily visible.

 

Front view of giant water bug’s head with hair-like antennae concealed in cavity beneath the compound eye (arrow).

 

 

FAMILY-BELOSTOMATIDAE-GIANT WATER BUGS

 

The giant water bug gets its name from the fact that members are very large (0.8 to over 4 inches) and aquatic.  They can generally be recognized by the overall shape, color (flattened, brown to gray) and presence of well-developed raptorial front legs.

 

 

Local  species of giant water bug

           They commonly are found in lakes, streams and ponds and typically feed on other insects, snails, tadpoles and small fish.  Some of the huge South American species are capable of preying on frogs, salamanders, mice, and even small rats.  These are voracious predators and capable of delivering a painful bite if handled carelessly.  They inject a poisonous fluid into their prey and suck them dry, much like a spider does. The author once dove into a swimming pool in Acapulco and was immediately bitten by the sole giant water bug present.  This 4-inch creature is now pinned and can be found in our entomology museum.

 

         Giant water bugs are strong fliers, frequently leave the water to feed and are readily attracted to lights.  They also have been called the electric light bugs, toe biters and fish killers.  In some U.S. species, the female lays her eggs on the back of the male who carries them around until they hatch.  As in several groups of aquatic hemipterans, a giant water bug is capable of trapping an air bubble between its hemelytra and abdomen.  The spiracles of the respiratory system open into this bubble.  This air bubble is then carried with the adult (much like a scuba tank) and allows it to be submerged for several hours.

 

Male giant waterbug with eggs.  Image courtesy fickr.

 

            Males attract the females doing a series of periodic movements near water surface generating ripples in the water known as display pumping. An accompanying low frequency acoustical signal has been observed in at least one species of Belostomatinae. Before a female begins ovipositing the eggs, she mates with the male. Then a series of intercalated matings and ovipositions occur, females ovipositing 1-4 eggs in each ovipositing bout. An egg batch can have more than 100 eggs so a couple may copulate more than 30 times before female oviposits all the egg batch.

         As one might expect, giant water bugs are a source of human food.  It came as no surprise to the authors while shopping in the day market in Chiang Mai, Thailand, that there was a giant water bug stall next to the chicken and egg stall.  The vendor had a large basket containing around 200 four-to-five inch long giant water bugs.  Each of the bugs’ legs and beaks were tied down with a rubber band to prevent them from escaping and biting.  Apparently certain oils are extracted to make a spice or the entire insect is deep-fried and consumed.  They are collected from the rice fields.

 

 

            FAMILY-CORIXIDAE-WATER BOATMEN

 

Water boatmen are the most common group of aquatic insects in North America, in both the number of species and abundance of individuals.  They are extremely common in lakes and ponds with a few species found in brackish water along the seashore.  The body is elongate-oval, somewhat flattened, and usually dark gray in color.  The hind legs are elongated and oar-shaped, while the front legs are scoop-shaped (arrow) and used to scrape algae, their main diet, off rocks. 

The only family of aquatic Hemiptera that remotely resemble water boatmen are the backswimmers.  These two families can be separated by several characteristics.  Notable differences are the shape of the front legs and beak or rostrum.  As discussed above, the front legs of the water boatmen terminate in the scoop-shaped tarsi.  In the case of the backswimmer, the front tarsi are sharpened, which is an adaptation for their predatory way of life. Additionally, the beak of water boatmen is cone shaped, while that of a backswimmer is elongated and pencil-like in shape. An even more discernable characteristic is the shape of the body.  When viewed from the front, the back of water boatmen is distinctly flattened, while that of a backswimmer is distinctly pyramid shaped or humpbacked.

Because the insects are so common in aquatic situations and are a primary convert of plant-to-animal matter, they are considered very important in food chains.  In many areas of the world water boatmen are even consumed by humans. The adults are not normally consumed, as they are too crunchy; however, in the lakes of Mexico large rope mats are placed in the water and serve as a suitable substrate for egg deposition.  Periodically the mats are removed and the eggs are scraped off and ground up into flour high in protein.

 

 

              

 

           An adult water boatmen with scoop-shaped (arrow) front legs. 

 

 

         FAMILY-NOTONECTIDAE-BACKSWIMMER

 

The backswimmers, as you might expect, are so named because they swim on their backs.  They are very similar to the water boatmen in shape, but the dorsal side of their body is more roof-like in cross section and they typically are lightly colored.

 

       Backswimmers are aquatic and most rest just below the surface of the water with the head angled downward. They are predaceous, feeding on other insects and, occasionally, tadpoles.  They are important in the biological control of mosquito larvae.  A common method used to catch mosquito larvae and pupae, is to drift up under them after releasing hold of an aquatic plant to which they have been clinging.

 

       These insects are capable of inflicting painful bites if carelessly handled.  The males of many species can produce a 'squeaking' sound by rubbing their front legs against their beaks (stridulating).  This sound is associated with the backswimmer's courtship behavior.

 

       The action of swimming on the back is due to a ventral light reaction. That is, backswimmers swim with the most lighted part of their environment on the underside, or venter, of their bodies.  The importance of light in their orientation can easily be demonstrated by placing backswimmers in an aquarium with a dark board over the top and a light bulb shining through the bottom.  In this case the insects will swim with their venter toward the bulb or right side up.  As discussed, in nature it is to the advantage of backswimmers to swim upside down as their prey typically is on the surface of the water and they can float up in a position ready to attack.

 

FAMILY-NEPIDAE-WATER SCORPIONS

 

The water scorpions are a small family of very large aquatic insects with many species reaching 2 inches or more in length.  These insects occasionally leave the water and are slow swimmers.  They reportedly are capable of delivering a painful bite. They are commonly called waterscorpions for their superficial resemblance to a scorpion, which is due to the raptorial forelegs and the presence of a long slender process at the posterior end of the abdomen, simulating a tail. There are 14 genera in the family, in two subfamilies, Nepinae and Ranatrinae. Members of the genus Ranatra are sometimes called needle bugs or water stick insects as they are more slender than Nepa and its relatives. Waterscorpions feed primarily on invertebrates, but occasionally take small fish or tadpoles. Respiration in the adult is effected by means of the caudal process, which consists of a pair of half-tubes capable of being locked together to form a siphon by which air is conducted to the tracheae at the apex of the abdomen when the tip of the tube is thrust above the surface of the water. In immature forms the siphon is undeveloped and breathing takes place through six pairs of abdominal spiracles. The eggs, which are laid above the waterline in mud, decomposing vegetation, the stems of plants or rotting wood, are supplied with air by filamentous processes which vary in number among the genera.

In Nepa the body is broad and flat; but in an allied water-bug, Ranatra, which contains a single British species (R. linearis), it is long and narrow, while the legs are very slender and elongated.

                                                                                                                            A common  forms of waterscorpions. 

 

 

     FAMILY-GERRIDAE-WATER STRIDERS

 

         The water striders are long-legged insects that run or skate over the top of water to catch their prey, mainly other insects that fall accidentally onto the surface. The front legs are short and raptorial for catching and holding their prey while feeding.  The tarsi and other parts of the legs of these insects a covered with short hairs that are difficult to wet.  Additionally, the tarsal claws are antapical referring to the fact that they are positioned on the last tarsal segment before the tip and are capable of being retracted.  Therefore the claws do not protrude from the tip of the leg and do not break the surface tension of the water. This, plus the non-wettable hairs, allows these insects to walk on water.  Water striders are common in quiet water where they often occur in large numbers.

 

       Some individuals of a species are winged and some are apterous.  If a stream or pond dries up, the winged forms will attempt to fly to a new aquatic environment, while the apterous forms burrow in the mud or under stones where they remain dormant until the rainy season returns.  Water striders are one of the few types of insects that can be found in the ocean.  Ocean-inhabiting species are apterous as the ocean is not likely to dry up.

 

       For any fishermen reading this text, water striders are not good bait for trout or other fish.  It makes biological sense that any insect that lives on the top of water must have some mechanism for survival because, without this, they would be “sitting ducks” for any hungry fish.  In the case of water striders the mechanism is simple; they don’t taste good.  Water striders possess glands that produce foul tasting oil.  After eating a few, fish quickly learn to associate the foul taste with the insect and ignore them in future encounters.

 

            

                    

A common  species of water striders illustrating shadow of strider denting the water surface.

 

Terrestrial Bugs

 

FAMILY-ARADIDAE-FLAT BUGS

 

This is a relatively small family of approximately 800 species worldwide.  As their name implies they are very flattened which is associated with their way of life.  Temperate species commonly live under the bark of dead trees (again, with a few exceptions), while many tropical species are found in leaflitter or on fallen twigs or branches.

Most members of the family are thought to be mycophagous, feeding on fungi, but in truth, little is known of the feeding habits of most species, though they can be attracted to the pheromones of bark. Many of the tropical taxa are apterous (lacking wings as adults). Flat bugs are distant relatives of the more familiar stink bugs. Most have rudimentary or non-functional, under-developed wings.  Little else is known about their biology.

 

 

A tropical species of flat bug with rudimentary wings.  Image courtesy of Dexter Sears.

 

 

 

           FAMILY-BERYTIDAE-STILT LEGGED BUGS

 

This is a relatively small family of medium sized bugs.  They are easily identified by the their slender body and elongated legs.  In addition the antennae diagnostically terminates in a small knob-like segment.  Little is known about their biology but most are thought to be plant feeders.

 

                                                                                     

               Typical stilt legged bugs with slender body and legs.

 

FAMILY-REDUVIIDAE-ASSASIN BUGS, CONE-NOSED BUGS, KISSING BUGS

 

This big family is comprised of relatively large bugs (1/2 to 1+ inch in length) that are mainly predatory and with a few blood-sucking forms.  Assassin bugs are characterized by possessing a short beak, which terminates in a groove in the front part of the thorax. In addition the head narrow behind the eye giving the appearance of a neck and in many species the abdomen is widest in the middle and tapers at either end. Cone-nosed bug refers to the characteristic of the head being cone shaped in many species.

 

 

An assassin bug illustrating the short beak and narrowing of the head behind the eyes. 

 

Most species are predaceous on other insects, but some feed on the blood of humans and other warm-blooded animals.  The predaceous forms are considered beneficial but can also inflict a painful bite if handled.  In some cases the bite has been compared to that of a venomous snake.  The pain can be intense, with other symptoms including general swelling, faintness, vomiting and nausea and can last weeks or even months.  The bite of the blood-sucking forms, as one might expect, is not initially felt. The saliva of these forms contains both an anesthetic and an anticoagulant and, after a few hours, large, red swollen blotches frequently develop.

In Southwest Mexico and down into South America, some of the blood sucking forms are quite aggressive and come into homes at night to feed on humans. These frequently are referred to as "kissing bugs" because of their tendency to feed around the face and mouth.  Because they commonly feed at night when a person is sleeping, the most likely target is the face as the blanket does not cover it.

In Central and South America, kissing bugs can vector Chaga’s disease, a highly fatal disease of humans.  Most of the blood sucking assassin bugs that vector this disease belongs to the genus Triatoma.  This genus is well represented in the US but the disease does not occur here.

 

 

 A conenose bug (Triatoma spp.), a blood sucking form.  Image courtesy of Marcelo de Campos Periera.

 

The spined assassin (Sinea diademe) is one of the more common assassin bugs found in cropping situations throughout North America.  It is characterized by having many spines on the pronotum (top of prothorax) and front legs. This average sized (adult length ½ inches) bug feeds on many different agricultural pests.

 

 

 The spined assassin bug, one of the more common predators found in many crops.  Image courtesy of Clemson University Entomology.

 

There are several species of bee assassins that are distributed throughout North America.  The most common species is Apiomeris crassiipe, which measure around 0.6 inches body length.  . The species can be found in the United States ranging into tropical America. The common name bee assassins is derived from their frequent habit of sitting and waiting upon flowers and taking bees as prey. The bright colors are aposematic likely a warning to larger predators that a painful bite can be delivered.

Many species of this genus have a sticky resin pad located on their dorsal abdomen. The resin is thought to be derived from plant material and may play a role in defending eggs from predation, especially by ants. The genus presently consists of about 110 described species.

 

                                                         A bee assassin, a common predator of bees and other insects that visit flowers for nectar and pollen.

 

The wheel bug (Arilus cristatus), in the family Reduviidae, is one of the largest terrestrial true bugs in North America, being up to 1.5 inches, or 38 mm, in length; it is the only member of its genus. A characteristic structure is the wheel-shaped pronotal armor. They are predators upon soft-bodied insects such ascaterpillars, Japanese beetles, etc., which they pierce with their beak to inject salivary fluids that dissolve soft tissue. Because most of their prey are pests, wheel bugs are considered beneficial insects, although they can inflict a painful bite if handled carelessly.

Wheel bugs are common in eastern North America, although many people in the region have never seen them. They are camouflaged and very shy, hiding whenever possible. They have membranous wings, allowing for clumsy, noisy flight which can easily be mistaken for the flight of a large grasshopper. The adult is gray to brownish gray in color and black shortly after molting, but the nymphs (which do not yet have the wheel-shaped structure) have bright red or orange abdomens.

The wheel bug has characteristic dorsal armor, shaped like a wheel or cog. It moves and flies slowly, and in flight produces a buzzing sound. It has one of the most developed set of mouth parts among true bugs. Its beak arises from the anterior end of its long, tubular head and unfolds forward. The bug plunges its beak into its victim, pinning its prey with its front legs. It then injects enzymes into the victim, paralyzing it and dissolving its insides, and proceeds to drain all of the victim's bodily fluids. The bite of a wheel bug is painful and may take months to heal (sometimes leaving a small scar), so caution is advised when handling them.

The wheel bug is also noted to be very vicious in the wild, and cannibalistic behaviors between them have been noted; for example, nymphs may prey on nymphs and the female may feed on the male after mating is concluded.

It possesses two scent sacs (red-orange in color) that can be fired from its anus, usually in reaction to being disturbed. The scent produced by it is not as powerful as that produced by the stink bug, but is still strong enough to be detected by human noses. Colors include black and gray.

The reproductive cycle of the wheel bug initiates in autumn. When a pair of wheel bugs encounters each other and mate, the female will lay 40-200 small, brown, cylindrical eggs on a tree twig, and eventually die. The eggs will hatch in the next spring into eighth-inch long red nymphs, which will undergo 5 molts and metamorphose until they reach the adult stage the following summer.

 

A wheel bug, one of the larger assassin bugs with a nasty bite.  Image courtesy of Ron Billings, Texas Forest Service.

 

As with the wheel bug many tropical assassins pack a powerful bite.  One of our students was bitten on the finger by a rather large assassin bug in Thailand.  Her finger began to swell immediately.  Unfortunately she had a ring on that finger.  The swelling got so bad that the ring cut off circulation to her finger, which she could have lost.  Fortunately we cut the ring off in time.

 

FAMILY PHYMATIDAE-AMBUSH BUGS.

These odd-looking insects are sometimes placed in the same family as the assassin bugs.  They are commonly called ambush bugs after their habit of lying in wait for prey relying on their superb camouflage. Armed with raptorial forelegs, ambush bugs routinely capture prey ten or more times their own size.

The antennae have four segments. There are two ocelli. The beak has three segments. The tarsi also have three segments. The rear half of the abdomen expands beyond the edges of the wings.

These insects are often given family-level status and this classification is still used in some textbooks. Based on cladistic analyses, however, ambush bugs (Phymatinae) are part of the family Reduviidae (assassin bugs).

Most are relatively small, ranging from 0.3 to 0.5 inches in length.  They can readily be recognized by their distinctive shape including huge raptorial front legs.  Ambush bugs typically sit on flower heads waiting for butterflies, flies, bees and other insects that come for nectar and pollen.

 

 

An ambush bug waiting on a flower head for a bee or other insect.  Image courtesy of Ironchris.

 

                                                                            FAMILY-PENTATOMIDAE-STINK BUGS. 

 

Most members of this family are slightly flattened, shield-shaped and the scutellum (triangular area behind the top of the prothorax-arrow) is greatly elongated when compared to other Hemiptera.  In the case of the stink bugs this structure is at least half the length of the rest of the body.  The name Pentatomidae refers to their 5-segmented antennae.

 

 

A typical stink bug with well-developed scutellum (arrow) and five-segmented antennae.  Image courtesy of Clemson University Entomology.

 

Most members of this family are phytophagus, chiefly feeding on seeds and fruiting bodies; damage can result from fruit drop to disfigurement.  There are a few species including the two-spotted stink bug and anchor stink bug that are predatory in both the nymphal and adult stages.  In these cases they are typically general predators, feeding on those insects of appropriate size.

The harlequin cabbage bug (Murgantia histrionica), also known as calico bug, fire bug or harlequin bug, is a black stinkbug of the family Pentatomidae, brilliantly marked with red, orange and yellow. It is destructive to cabbage and related plants in tropical America as well as throughout most of North America, especially the warmer parts of the United States. In addition to cabbage it can be a major pest to crops such as broccoli, radishes and the ornamental flower cleome. Nymphs are active during the summer and in the South the bug can achieve three generations a year. In the North there is only one generation annually and the insects overwinter as adults.

Organic control involves hand-picking the insects off the plants (they can be dropped into soapy water to drown them) and being especially careful to remove and destroy all the eggs, which are black-and-white striped and laid in clutches of twelve. Despite their "warning coloration", they are non-toxic and can be safely fed to poultry or pet reptiles or amphibians.

     

      Adult harlequin bugs.  Image courtesy of Linda Tanner.

 

                                                                                                 FAMILY-SCUTELERIDAE-SHIELD BACK BUGS

This small family is closely related to the stink bugs.  It follows that they are similar in appearance and size to the Pentatomidae.  The unique characteristic of this family is that the scutellum is very well-developed and hoods or covers the entire top of the abdomen, consequently the hemelytra is not evident.  This often gives these bugs the appearance of a beetle rather than a true bug.  Of course they do have a well-developed beak, which quickly separates them from the beetles. Members of this family are more commonly found in the tropics.  Little is known about their biology but most are undoubtedly plant feeders.

 

           

          FAMILY-TINGIDAE-LACE BUGS

 

The lace bugs are not likely to be confused with any other family.  They are small (0.1 to 0.15 inches), oval to square in shape, flattened and their head, thorax and abdomen is typically covered with a raised reticulate (net-like) patterning .  Their head is often hooded or covered by the thorax.  The prothorax is typically expanded laterally and the abdomen is hidden (when viewed from above) by the wide lace-like hemelytra.  The nymphs are quite different in appearance than the adults.  They are typically black and covered with spines.  All stages are usually found on the undersides of leaves sucking sap and leaving black spots of excrement.   This group is distributed worldwide and consists of approximately 2,000 species.

Lace bugs are usually host specific and can be very destructive to plants. Most feed on the undersides of leaves by piercing the epidermis and sucking the sap. The then empty cells give the leaves a bronzed or silvery appearance. Each individual usually completes its entire life cycle on the same plant, if not the same part of the plant.

Most species have one to two generations per year, but some species have multiple generations. Most overwinter as adults but some species overwinter as eggs or nymphs. This group has incomplete metamorphosis in that the immature stages resemble the adults, except that the immatures are smaller and do not have wings. However, wing pads appear in the second and third instar and increase in size as the nymph matures. Depending on the species, lace bugs have four (few) or five (most) instars.

   

Sycamore lace bugs.  Image courtesy James Solomon, USDA Forest Service

 

          Sycamore lace bug is the most commonly encountered species ranging throughout North America.  It attacks sycamore, ash, hickory and mulberry.  It hibernates as an adult under bark.  Other common species attack cotton, beans, oak, eggplant, chrysanthemums, Hawthorne, Pyracanta and other hosts.

 

              FAMILY-NABIDAE-DAMSEL BUGS

 

This is a small family, all representatives of which are predatory in the adult and nymphal stages.  As with all predatory bugs their front legs are raptorial with a swollen femur. Because this is such a small family there is very little difference in the appearance from species to species.  One characteristic that is unique to this family is that they have a ladder-like arrangement of cells (arrow) on the outer margin of the front wings or hemelytra.

 

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A damsel bug, Nabis ferus, one of our most common predators found in agricultural fields. Arrow indicates ladder-like arrangement of cells on wing margin. Image courtesy of Jim Kalisch, University of Nebraska, Entomology.

 

Nabis ferus is one of the more common insect predators found in agricultural fields and orchards throughout North America.  Adults are approximately 0.4 inches in length and grayish in color.  Their prey includes but is not limited to aphids, leaf hoppers, tree hoppers and small caterpillars.

 

FAMILY-ANTHOCORIDAE-MINUTE PIRATE BUGS

 

This is a very small family of small insects measuring 0.1 inches in length or less.  A unique characteristic of this family is the appearance of a break in margin of the lower leathery part of the hemelytra.  One of the most common species in this family is Orius insidiosus that is distributed throughout the US and is commonly found in flower heads.  Common prey include the chinch bug, false chinch bug, thrips, corn earworm (eggs and early instar larvae), walnut husk fly eggs, mites and many other small insects and eggs.  These insects are abundant on corn in the eastern states laying their eggs on the silk. Minute pirate bugs are abundant in cotton fields throughout the US and are considered an important predator.

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 Orius insidiosus-an important predator in crops. .  Image courtesy of USDA, Forestry Images.

 

LYGAEIDAE-SEED BUGS

This is a rather large family of medium sized bugs.  Because it is so large, there is more diversity of form when compared to some of the smaller families.  A fairly useful tool in family determination in the Hemiptera is that if a family isn’t immediately recognized by form, then check the venation in the hemelytra.  In the case of seed bugs there are characteristically 4 to 5 simple veins in the membrane of the hemelytra (Figure 58-arrow).  A simple vein is one that is not branched and does not enclose an entire cell.

 

                                                                                 

                           The membrane of 2 seed bugs (mating) illustrating 4 simple veins in membrane of hemeytra. Image courtesy of Peter Chew.

As might be expected from such a large family, there is some variation in the feeding behavior of different species.  Most are plant feeders while a smaller percentage is predatory.  The large and small milkweed bugs are 2 commonly encountered, brightly colored species that occur throughout most of North America. They are of no economic concern because they feed exclusively on milkweed.

The milkweed bug, Oncopeltus fasciatus, feeds mainly on seeds, particularly those of the milkweed. It is commonly used in science due to ease of rearing and ease of dissection.

                                                                                               

The  adult is a 9–18 mm long insect. Mature adults are orange with black rhomboidal spots at both end of a body and a black band in the middle. Freshly molted individuals are pale yellow with gray spots that change into black with time. Bright orange instars resemble adults, with orange-black pattern different than in grown individual and without wings. However, wingpads are visible and become more pronounced with each molt. Adult females have several black spots on rear part of their abdomen, while males have only one.

The habitat of the large milkweed bug spreads east of the Rocky Mountains. It is found as far north as Ontario, Canada, but is more abundant in south-eastern United States. Groups of insects in all stages of development are commonly found between May and October on common milkweed plants.

Adults that survived winter mate in May-June, when common milkweed plants have grown enough to provide shelter. During mating, female and male may become connected for up to 10 hours. Eggs are laid on seed pods or under a leaf. Average female lays 30 pale orange eggs in a day, in several batches during summer. Eggs change color, becoming more intensely orange toward hatching. This insect undergoes incomplete metamorphosis. Nymphs hatch after about 1 week and molt 5 times before becoming adults. Adults and nymphs feed on milkweed plant juices, seeds and occasionally on other plant juices. When their native plant is scarce, they may become scavengers and predators. Both nymphs and adults use milkweed as their primary source of food.

After feeding on milkweed plant or seeds, the insects accumulate toxic glycosides in their bodies. This, combined with warning orange color, protects them against predators (aposematism).

Bugs can be bred with relative ease at home, serving as biology specimens. In captivity, they are kept in glass jars with cloth on top. If milkweed seeds are not available, they are fed shelled sunflower seeds, juicy fruits (watermelon) or some nuts. Water (in form of soaked tissues) must be provided to keep the colony alive

The chinch bug is an important pest on a variety of crops including corn, wheat, barley, sorghum, oats and rice.  It occurs from the East Coast to the Middle Plains attacking succulent grain.  They migrate on the ground sometimes destroying entire crops.  The false chinch bug occurs throughout North America attacking a wider variety of plants. This insect occasionally breeds in up to huge numbers on weeds.  When the weeds die out the insects migrate and accidentally enter homes in huge numbers.

 

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Chinch bugs.  Image courtesy of Jim Kalisch, University of Nebraska Entomology.

Geocoris is another genus of insects in the family Lygaeidae (although sometimes the subfamily is elevated to the family "Geocoridae"). Commonly known as the big-eyed bug, Geocoris is a beneficial predator often confused with the true chinch bug, which is a pest. The two most common species are Geocoris pallens andGeocoris punctipes. Both are predators and occur in many habitats, including fields, gardens, and turf grass. Big-eyed bugs are considered an important predator in many agricultural systems and feed on mites, insect eggs, and small insects such as pink bollworm, cabbage loopers and whiteflies. Adult big-eyed bugs are small (about 3 mm) black, gray, or tan with proportionately large eyes. Eggs are deposited singly or in clusters on leaves near potential prey. They develop with incomplete metamorphosis (there is no pupa) and take approximately 30 days to develop from egg to adult depending on temperature. Both nymphs and adults are predatory, but can survive on nectar and honeydew when prey is scarce. Big-eyed bugs, like other true bugs, have piercing-sucking mouthparts and feed by stabbing their prey and sucking or lapping the juices. Although their effectiveness as predators is not well understood, studies have shown that nymphs can eat as many as 1600 spider mites before reaching adulthood, while adults have been reported consuming as many as 80 mites per day..

                                                                                                                               

                                                                                                                             Big eyed bug feeding own whitefly nymphs.

 

FAMILY CIMICIDAE BEDBUGS

 

The common bed bug (Cimex lectularius) is the main species that is currently found infesting buildings and homes throughout the United States and other temperate climates.  There are a number of other species of bedbugs found around the world. These species are more frequently associated with birds and bats and have been found on occasion in homes when these have been nesting on/within the structure.   The tropical bed bug, Cimex hemipterus, occurs commonly throughout tropical areas of the world thus preferring higher temperatures and humidity that Cimex lectularis. In continental Europe and the United States, established infestations of this species are rare; in the Western Hemisphere, it is seldom found north of Mexico and Puerto Rico, or south of Peru and Brazil. Occasional limited populations have been found in Florida and Chile. Other species of bedbugs, including bat bugs, swallow bugs, and other bird-feeding bugs), occur in various north and south temperate parts of the world, may occasionally bite humans and are found sporadically in or around homes and other structures..  

Cimex hemipterus, occurs primarily in more tropical areas but has been found in temperate areas of the US particularly for people engaged in international travel.   Bedbugs have been known by a variety of names including wall louse, mahogany flat, crimson rambler, heavy dragoon, chinche, and redcoat. 

                                                                                        

                                                             

 Left. Bed Bug with Piercing Sucking Mouthparts Inserted into Host (human) Sucking Blood.  Right Piercing Sucking Mouthparts of Bedbug Images Courtesy CDC.

Identification.   As indicated in above figure adults of these insects are reddish-brown, oval, flattened insects about ³/16" long and up ¹/8" wide. Once engorged with blood they are swollen and dull red. Their eyes are deeply pigmented and the sides of the collar-like pronotum curve slightly around the head. The immature (nymphs) vary considerably in size with almost colorless new hatchings being about the size of a period in this article. Eggs are white, oval and about 1 mm long (very difficult to see with the naked eye).  The tropical begbug is about ¼ large than the common bedbug.

 

Bedbug History. It is thought that bedbugs were originally ectoparasite of bats in caves, but then changed hosts to include humans (cavemen) once they were found in the same habitat.   They are mentioned in medieval European texts and in classical Greek writings back to the time of Aristotle. These pests were originally brought to the United States by early colonists from Europe.  Colonial records of the early 18th century document severe bedbug infestations in England and Canada, but no apparent indication in American Indians. There are reports of early sailing vessels being heavily infested with bedbug and in some instances passenger were not allowed to bring bedding material on board.  During the early 1900s bedbugs infestations were quite common in American homes.  They were rated amongst the top structural pests at that time with an estimated 1/3 of all residences having infestations at one time or another.  They were especially prevalent in lower income areas.  However with the discovery and use of DDT and other “new” insecticides in and around homes the presence of these pests quickly disappeared.  As typically occurs bedbugs developed resistance to DDT after a few years but other chlorinated hydrocarbons (such as lindane) and organophosphates (malathion) were used to keep these pests at a low level. Off course the key factor as to why these chemicals are more effective in controlling bedbug as compare to modern available chemicals is persistence.  For example DDT when sprayed on a bed remains active for up to one year. With this a bedbug that came to feed on a sleeping person was eliminated and since all would need to feed at one time or another the infestation was eventually eliminated.

In many undeveloped countries however the bedbug remained an important pest. In the past ten years bedbugs have made a tremendous comeback in many areas of the world including all 50 states, as well as Guam, Puerto Rico and American Samoa, Canada, Australia, parts of Europe, and parts of Africa.

 

In the US a few of the major cities that are currently experiencing considerable bedbug’s infestations include Los Angeles, San Francisco and New York. New York City has experienced increased cases of bedbug infestations.  Bedbug-related calls to pest control operators are escalating at a fantastic rate From June 2009 to June 2010, there were more than 31,000 calls in New York City alone. Bed bug infestation in the United States is increasing at an alarming rate. Some pest management firms have reported more than a 10-fold increase in bed bug treatments in recent years (Cooper, 2006). In a recent online survey of 509 U.S. pest control firms, 91% report encountering bed bugs in the past two years; 37% said they encountered them five years ago, and 21% recalled seeing them more than 10 years ago. Respondents who reported seeing bed bugs a several years ago indicated the frequency was very low, never more than one or two incidents per year. In a related survey question, 23% of companies indicated they treated more than 20 different bed bug infestations last year, while 6% battled more than 100 (Potter, 2008).

Some domestic cases have escalated to extreme levels, causing residents to label the infestations "house herpes".  In California one of the larger companies that use canines to detect infestations of these pests reported that they performed a mere 12 searches ten years ago.  This year they reported 33,000 such searches. The National Pest Management Association reported a 71% increase in bedbug calls between 2000 and 2005.  One report claimed that 25% of the North Carolina 700 hotels surveyed between 2002 and 2006 needed bedbug treatment. 

Why the Increase. There are several theories as to why this increase has occurred.  However nobody knows for sure.  Part of the reason may be too our shrinking world. World travel is on a tremendous increase.  People commonly travel to and from all parts of the world, including areas where bedbugs are common. Business and leisure travelers regularly travel between all the continents. Developed countries are increasingly multicultural, with residents moving back and forth from their homelands.  Of course bedbugs are great hitch-hikers easily traveling in luggage on other items.

Another possible reason for more bedbug problems is the increase in illegal aliens and other temporary workers.  In many cases these individual are coming in from Mexico and Central America (countries where bedbug population have remained fairly common place).  They commonly (especially temporary workers) shift in and out of group residences, mostly in low- income apartments.  It is not uncommon for individuals to constantly change or leave residences for a new location as jobs change or for them to return to their home country.  These conditions can quickly lead to importation and movement of these pests.

Second-hand stores, thrift shops, swap meets, flea markets, antique and Goodwill stores are on an increase in the US, especially with the current economic crisis.  Of course any used item is a possible source of the “initial infestation”.

Another recent theory about their reappearance involves potential geographic epicenters. Investigators have found three apparent United States epicenters at poultry facilities in Arkansas, Texas, and Delaware. It was determined that workers in these facilities were the main spreaders of bedbugs, unknowingly transporting them from the poultry farms to their places of residence and elsewhere.  Bedbug populations in the United States have increased by 500 percent in the past few years.

Also significant changes in pest control practices in addition to the development of resistance to modern day pesticides (pyrethroids) has very likely added to the successful re-establishment of bed bug populations in the United States and possibly abroad.  In the past, hotel rooms, homes and other indoor locations were typically treated on a regular basis with residual pesticides. Crack and crevice treatment was a standard and commonly used technique for German cockroach control. As a result, bedbugs introduced during travel or other means were likely to contact these pesticides in their daytime hiding places.  However during the mid 1990's there was a significant shift in these pest management practices. Routinely scheduled treatments of baseboards in hotels, motels and apartments were replaced with the use of baits for pests such as ants and cockroaches. As a result with the absence of the residual pesticide applications, bedbugs were able to travel freely and safely from the luggage or other location to the bed, and successfully begin an infestation.  Many professional consider it no coincidence that the dramatic rise in bedbug activity came approximately 10 or so years after applicators stopped spraying for cockroaches.

Biology.  The name bedbug is somewhat of a misnomer.  These insects are not necessarily found in or around beds but since the common bedbug in the US feeds on human blood during evening hours (between midnight and 5:00 am) it follows that they most commonly occur around or on beds as this is where the food is, namely us. Bedbugs are attracted to CO2 produced by our breathing and our body heat.  However, they are only able to detect these host cues over short distances (about 3 feet away for CO2 and even less for heat). It is not well understood how they are able capable of finding a person in a bed while initially located in a closet or other distant location. Even though they have a very flat body (definitely not streamline) and relatively short legs they are able to move relatively quickly, and it is thought that they randomly wander in search of food. In most cases the majority of an infestation is found on the bed. However, this is not always possible in heavy infestations where bed bugs are crowded and many bed bugs have to seek refuge at distances several yards from the host

Bedbugs exhibit gradual metamorphosis.  That is they pass through 3 stages during the life cycle, namely egg, nymph and adult.  The nymphs are very similar in appearance to the adults except they are smaller but gradually increase in size with progressive molts.  There are 5 nymphal instars or sizes.

 

The eggs are tiny, whitish, and hard to see on most surfaces without magnification (individual eggs are about the size of a speck of dust or period on this page). When first deposited they are sticky and readily adhere to surfaces thus making them difficult to remove. .  Under favorable conditions, each female lays 100 to 500 eggs at a rate of between 1- 7 eggs per day for about 10 days.  She will then have to feed again to produce more eggs and is capable of producing between 5 and 20 eggs from a single blood meal. Maximum egg deposition occurs when the temperature is above 70°F (21°C) and typically ceases when temperatures drop below 50°F (10°C). Eggs and their shells are found, singly or in clusters, in or near the crevices where bed bugs are hiding. At temperatures above 21°C (70°F), eggs hatch in about 10 days. At lower temperatures, hatching may take as long as 28 days.

 

Under optimum conditions the hatching rate of bedbug eggs results approximately 3% mortality.  Even under the best conditions some bed bug nymphs will die prior to becoming adults. The first instars are particularly vulnerable. Newly hatched nymphs are exceptionally tiny and cannot travel great distances to locate a host. If an egg is laid too far from a host, the first instars nymph may die of dehydration before ever taking its first blood meal. However, laboratory studies have found that overall bedbug survivorship is good under favorable conditions, and that more than 80 percent of all eggs survive to become reproductive.     Due to the large numbers of eggs a female can produce under optimal conditions (temperatures >70° F but < 90° F, and in the presence of a host), a bed bug population can double every 16 days.

 

Without a source of food bedbugs can enter a dormant condition and reportedly can live for 18 months while well-fed specimens typically live six to nine months. However a recent laboratory study has shown that starvation has a negative impact on bed bug survival. This modern study contradicts European studies conducted in the 1930s and 40s when it was determined that starved bedbugs could survive periods lasting more than one year. While this may have been true for individual bedbugs in the UK living at very low temperatures (< 40° F; because of no central heating); modern bedbugs collected from homes in the United States do not live that long. On average starved bedbugs (at any life stage) held at room temperature will die within 70 days. Most likely these bedbugs are dying of dehydration rather than starving to death. Because bedbugs have no source of hydration other than their blood meal. 

 

The unfed first instar nymph is almost translucent in color but subsequent nymphs progressively darken in coloration. Recently fed nymphs are blood red in coloration.  As with all insects bedbug are cold blooded, meaning they take on the temperature of their surrounding environment.  Correspondingly, the cooler the surrounding environment the slower their time of development.  

 Bedbugs will travel 5-20 ft. from an established harborage to feed on a host.  Nymphs and adults are gregarious (found together in groups).  This grouping or “nesting” behavior is a result of two distinct pheromones, namely an airborn aggregation pheromone that attracts the bedbugs to the location and an arresting pheromone that causes them to settle. Although they normally venturing out to feed in the early morning hours they occasionally feed at other times if given the opportunity and have been observed active during all periods of the day. Typically only when bedbugs are starved will they feed during daylight hours.  However there are many well documented cases of bedbugs feeding during daylight hours. In more than one cases they have become established in movie theaters, (especially older theaters with leather seat).  Apparently during the day they come out of the seats to feed when the lights are turned off. 

They can gain access to their host by crawling up the legs of a bed or they have even been observed crawling across and dropping from the ceiling to float (flattened like a falling leaf) down to their host.

 

                                                                                   Aggregation of Bedbugs.  Image Courtesy w.en. User Rogesoss

Mating. The mating behavior of bedbugs is strange and at times quite competitive. Males inject their sperm into the female by puncturing the body wall as the female has no natural opening for reception of his sperm. Of course the sperm then swim throughout the female’s body cavity eventually finding and fertilizing her eggs. Apparently this is not limited to females as it is not uncommon to find males with copulation scars where other males have penetrated their body wall.  In some species this apparently happens when a male penetrates another male that is copulating with a female and injects his sperm into the mounted male.  In this case some of his sperm find its way into the sperm ducts of the mounted male which in turn is injected into the female upon ejaculation.  A "bedbug alarm pheromone" consists of (E)-2-octenal and (E)-2-hexenal. It is released when a bedbug is disturbed, as during an attack by a predator. A 2009 study demonstrated that the alarm pheromone is also released by male bedbugs to repel other males who attempt to mate with them. 

                                        Bedbugs in Traumatic Insemination. Image Courtesy of Rickard Ignell, Swedish University of Agricultural Sciences                 

Symptoms of Bites and Treatment.  Since bedbugs are so secretive one of the first signs of their presence (especially in an initial small infestation) frequently comes from their feeding on the occupants.  The bug pierces the skin with two hollow feeding tubes.  One functions to inject saliva which contains anticoagulants and anesthetics, while the other withdraws the blood of the host.  The anticoagulant serves to keep blood flowing (preventing coagulation) in the tiny mouthparts while the anesthetic servers to numb the area and prevent detection of their presence. These injected chemical are protein based and the body reacted to their presence producing antibodies. This frequently results in what is referred to as an antigen-antibody reaction-or put more simply your system become allergic to the chemicals.

In a fairly large percentage of people the bite cannot be felt until minutes, hours or even later with the first indication of a bite usually occurring from the desire to scratch the area.   It may take multiple feeding for symptoms to occur.  For this reason plus their secretive behavior an initial infestation may not be detected for some time.  One estimate is that on an average it will take 3 months for the initial infestation to develop to the point where it is detected by the resident. Repeated exposure to bedbug bites leads to more severe skin reactions. In one sample from 2009, 18 of 19 persons had a skin reaction after bedbug exposure, but usually only after repeated controlled exposure. With repeated exposure, the latency between the bite and the skin reaction decreased from about 10 days to a few seconds. However, there is no typical reaction to bedbugs feeding on a person.  The symptoms may vary considerable due to a number of factors including but not limited to degree or number of bedbugs present, previous exposure, duration of the infestation, individuals physiological reaction to feeding, differences in skin type and species of bedbug involved.

There are 5 established reactions, namely no reaction (due to no or few antibodies produced), delayed reaction, delayed plus immediate reaction, immediate reaction only and no visible reaction (due to circulating excess antibodies).  Most human reactions due to bedbug feeding consists of a raised red or flat welt which is often accompanied by very intense itching which can last for several days.

                                                                                              

                                                                              Immediate Reaction to Bedbug Feeding after 30 minutes.

It is important to recognize that there are many potential causes of itching and irritation other than bedbugs.  As a result the mere present of welt, itching or other skin abnormalities is not a reliable symptom of the presence of these pests.  Even dermatologists do not possess this capability.  This is of significant importance considering the current frenzy and paranoia about bedbugs in the United States.  It is quite probable that pest control companies will receive many “false alarms” about bedbug infestations. Allergies, cosmetics, medications, and environmental contaminants all can produce reactions similar to insect bites. There are four general categories of skin irritations, namely biting arthropods (e.g., insects or mites), personal use products, environmental factors and health related conditions.

Biting Insects. The typical symptoms of bedbug bites are quite similar to that of  mosquitoes but in the case of the former the welts tends to last longer than that of the latter. Also mosquito bites (at least those occurring while sleeping) are typically found on the face or other areas not covered when sleeping while those of bedbugs can occur all over the body. Also bedbug bites may not become immediately visible and can take up to nine days to appear while those of mosquitoes are typically immediate. On occasions bites from mosquitoes may eventually result in local swelling.  There can be many reasons why you might get a mosquito bite swelling, however, it is usually a sort of allergic reaction. If you move to somewhere new, you will often get a mosquito bite swelling after a bite, although after a few months or longer mosquito bite swelling will not occur. Sometimes it takes a lot longer for your body to build up a tolerance. Eighteen months, if you move to another country.

                                                                                  

Bedbug bites tend not to have a red dot in the center such as is characteristic of flea bites. A trait shared with flea bites is tendency towards the pattern of sequential bites often aligned in rows of three. It is thought this may be caused by the bedbug being disturbed while feeding and relocating half an inch or so farther along the skin before resuming feeding. Alternatively, the arrangement of bites may be caused by the bedbug repeatedly searching for a blood capillary.  Fleas usually bite people around the ankles, producing a small, red, hardened, and slightly raised welt. In addition fleas are most often associated with pets, although the presence of mice, rats, squirrels, skunks, or raccoons can also result in fleas infesting a home.  Finally fleas most often bite humans when their preferred host (pets, etc) is removed from the premise.  As long as a dog or cat is present in the house hatching fleas will go to that humans rather than biting humans.

                                                                                          

                                                                                                                           Spiders

A common complaint is spider bites.  In actuality spider biting humans is very rare.  I am 70 years old and have never been bitten by a spider.  Regardless spider bites are characterized by two tiny puncture marks on the skin corresponding to their paired fangs.

 

                                                                                     

 

                           When the brown recluse bites, it is often painless — then skin reddens, turns white, develops a red "bull's–eye," blisters, and becomes painful. 

                            Subsequently there is a degree of necrosis or rotting of the tissue.

                                                                                    

                                                                                                                        Mites

Mites are very tiny arthropods which occasionally infest structures and bite people. In most cases, the infestation can be traced to birds nesting in an attic or on a window ledge, etc., or to an infestation of mice or rats. When a bird or rodent dies (or the young leave the nest), thousands of parasitic mites can migrate indoors and bite humans.   Biting mites are tiny but visible to the human eye.  The human itch (scabies) mite burrows into the skin, causing intense itching and irritation. Skin between the fingers, the bend of the elbow or knee, and the shoulder blades are areas most often affected. The intense itching is accompanied by a rash.  A distinct symptom of scabies is a linear reddish rash as indicated in the left hand corner of the following figure.

 

                                                                                            

                                                                                                                                                        Lice

Of course there are three types of lice that infest and bite humans.  Generally speaking the only type of louse that may be commonly encountered are head lice.  As indicated by their name these lice occur on the head rarely leaving and causing itching of the head. The nits or eggs of these pests are glued to the base of the head hairs.  The (see below) are similar in appearance to dandruff but remain attached to the hair when touched-dandruff moves.

 

                                                                                        

                                                                                                                          Chiggers

Chiggers also bite people and generally are too small to be seen without magnification. Chiggers (the larval stage of the harvest mite) live outdoors in tall weeds and grass. They crawl onto people and move upward until they encounter a point of constriction between skin and clothing, such as around the ankles, behind the knee, or at the waistline. Chigger bites produce a hardened, red welt which begins to itch intensely within 24-48 hours after exposure to the mite. Consequently, people may not associate the irritation with the fact that they were bitten while walking outdoors a day or two before.  Most frequently the bites occur around the ankles.

                                                                                            

 

Household Products. There are literally hundreds of products that are capable of causing itching and irritation which are far more common that those resulting from arthropod bites.  Some of the more common products associated with these symptoms are phosphate detergents, soaps, cosmetics, ammonia-based cleaning agents, hair products, medications, and printing inks.  Certain types of clothing, particularly those which contain fire retardants are common sources.

Physical and Chemical Irritants. If two or more individuals experience the same irritation (especially in the absence of biting insects), the cause is typically environmental conditions or contaminants dispersed in the air. These fall into two categories.

Physical irritants: The most common physical irritants are tiny fragments of paper, fabric, or insulation. When these fibers contact the skin, they can produce symptoms ranging from a “crawling sensation” to intense itching accompanied by a rash, welts, or open sores. In these cases the irritation typically occurs over exposed areas of the body such as arms, legs, neck, and head.

Irritation produced by paper fragments is especially common in offices where large quantities of paper are processed daily. Continuous-feed paper from computers and multi-page forms generate large amounts of fragments covering office furniture and other areas.

Newly installed or badly worn synthetic carpet, drapes, or upholstery also shed fibers which can irritate skin. Other potential sources of irritation are insulation fibers released into the air by heating/cooling systems in need of repair and sound-deadening fibers embedded into drop-ceiling tiles. These latter sources are especially suspect if there have been problems with the air handling system or recent repair work on the ceiling.

Irritation is aggravated by static electricity which increases the attraction of the tiny charged fibers to exposed skin. Low humidity, electronic equipment, and nylon (e.g., from carpeting, upholstery, or women’s stockings) all increase levels of static electricity and the potential for problems from fragments or fibers. Static electricity may also cause body hair to move, giving the impression of insects crawling over the skin.

 

Dry air alone can cause irritation, producing a condition known as “winter itch.” As skin loses moisture, itching results. A similar reaction can occur from changes in temperature; these tend to make skin more sensitive. A skin moisturizer is often helpful in these situations.

Airborne chemical irritants: Indoor air pollution can be a serious problem in modern office buildings and other energy-efficient structures where air is recirculated over and over. Indoor air pollution can also be a problem in homes. As the concentration of

chemical contaminants in the air increases, people may experience dizziness, headaches, and eye, nose, or throat irritation. Certain air-borne contaminants can also produce rashes and skin irritation similar to insect bites. Chemical contaminants most often

responsible for these reactions include ammonia-based cleaning agents, formaldehyde emitted from wall and floor coverings, tobacco smoke, and solvents and resins contained in paints, glues, and adhesives. Reactions to airborne chemicals most often occur in buildings with inadequate ventilation, especially those that are new or have been refurbished with new paint or wall or floor coverings

Itching and skin irritation are common during pregnancy (especially during the last trimester) and may also occur in conjunction with diabetes, liver, kidney, and thyroid disease, and herpes zoster (shingles). Food allergies are another common cause of itching and irritation.

 

An increasing possible common cause of the sense of itching skin is associated with the use of meth, the drug of choice in many areas of the US.  Individuals that are hooked on this drug sense itching or irritation of the skin and continually pick at their skin. I recently was contacted by a home owner who thought she had bedbugs, wanting to know more about these pest I agreed to come over and check out the situation.  On arrival she showed me the so called bed bug bite.  She had been to a dermatologist suggested bedbug were the probable cause of the same.  After close inspection no bedbugs were found.  I did notice that her pupil were quite dilated and her boyfriend indicated that she continually picked at the areas of the bites-enough said.

Delusory Parasitosis-Entomophobia.  Again considering the current notoriety that the American public has been experiencing in the past several years there a large number of individual are afraid or paranoid about the possible presence of bedbugs in their homes. These two distinct phenomena are both based on the fear of small creepy creatures.

Entomophobia. As the name implies, entomophobia is the fear of insects. Based on a national survey, the fear of insects is ranked third in adults—closely behind the fear of public speaking and death. The fear of cockroaches is frequently ranked number one in the insect world.  I would imagine that the fear of bedbugs has recently surpassed that of cockroaches.

Delusory Parasitosis. This can defined as a paranoia, or irrational fear, of small creepy non-existent creatures. Because mites are so small, in many cases this condition is diagnosed as a mite infestation. Even more commonly with the notoriety of bedbugs the pest control operate who I called in for inspection of a possible bedbug infestation will actually dealing with this phenomenon. Delusory parasitosis is more common than one might expect. Frequently, people who are inflicted with this malady are quite normal in all other phases of life and lead productive lives.

I was quite unaware of this phenomenon until one day a man in his mid 40's walked into my office and indicated that the UCLA Medical Center had referred him to me. He indicated that he and his home were infested with small 'bugs' that he could not eradicate. After a short discussion he reached out into the air and indicated I had them in my office also. I responded that he must have brought them with him. He further stated that he had captured some and placed them on a piece of scotch tape. He related collecting each ‘critter.’ The first had bitten him on the leg and then disappeared under his skin, but he dug it out with a sewing needle. The second was on his pants cuff and bit him on the ankle. The third was found swimming around in his toothpaste. After considerable discussion we examined each 'critter' with a microscope. Needless to say, none resembled an insect or mite. Indeed, they were small grains of sand, pieces of lint and so on. However, even after this close inspection and working with him over a several-week-period, he could not be persuaded that the attacking creatures were imaginary. The situation became so bad that he convinced his wife that she was also infested. They had arguments over who had the most. They couldn't get them out of their home even though several exterminators were called. Because of the infestation the home was eventually sold at a considerable loss. Eventually, partly because of the turmoil, their marriage ended in divorce.

There have been many similar situations since then. One of the most unusual occurred a few years ago when a city official from Mission Viejo (Orange County) called me and indicated that he had a whole neighborhood infested with scabies mites (see below). Scabies are parasitic mites that commonly infest humans. At the time this didn’t seem questionable because a number of the people had been to medical doctors and had been treated for this mite. These treatments didn’t seem to solve the problem, so I was brought in as a consultant. The main problem was centered on one particular resident. This woman apparently had convinced much of the neighborhood of the widespread infestation. She was using very drastic measures to try to eliminate these mites from her house and family. She would use lye to scrub down the beds on a weekly basis. On several occasions she washed her kids down with gasoline. Of course, upon hearing this, I began to realize that the whole situation was more than a little irrational. The final clincher was when she indicated that the whole problem started when she brought a potted plant back from Arizona and, while it was sitting in her bathroom, a pod grew out of it and blew these tiny critters all over the neighborhood.

Probably the most severe and possibly dangerous was a recent case where a tenant was suing his landlord for an infestation of a number of household pests.  According to him the apartment he rented was infested with cockroaches, bedbugs, house dust mites (in the attic), cats, rats, mice and even scabies mites.  According to him he became so paranoid about the whole situation he stopped taking his HIV medication and subsequently developed AIDs.  He called in a pest control company that treated mainly for cockroaches but could not find any bedbugs, rat or mice.  He indicated that the company told him that the attic was full of housedust mites that were biting him and causing a severe rash.  He went to a emergency center that routinely prescribes 5% permethrin cream for scabies mites.  This material is quite effective and it typically takes on treatment for successfully eradication even though there is enough in on tube for 3 treatments. Needless to say he treated himself on 3 separate occasions with the material. However since the rash remained he went to another doctor (this time through his medical insurance) and was prescribe an addition tube of the material.  Needless to say he also went to his AIDs doctor for another prescription.  In the end he received 3 separate prescriptions from each of the 3 doctors and treated himself 27 times over a few month period.

If that wasn’t enough he decided to treat for cockroaches and bedbugs (even though two separate pest control companies were brought in for the same purpose with the second finding no roaches or bedbugs).  He initially tried several different chemicals that he sprayed with apparently no acceptable results.  He then tried using aerosol bombs lighting several per room on three occasions. He was luck he didn’t blow the places up. Finally on the initial visit to the emergency room the doctor checked for head lice but didn’t find ant.  Of course that wasn’t enough for the tenant so he routinely treated for head lice with an over the counter pesticide cream. The amazing thing, besides that he didn’t kill himself with all the pesticides, he received a $20,000 settlement in the lawsuit.

A colleague from NCSU, Mike Waldvogel, reports similar experiences. He states he has received a variety of imaginary critters in vacuum cleaner bags, pillows cases, panty hose, skin samples, glue boards (like the one you use for catching mice) and (the one he described as the ultimate) a bottle (formerly a pint gin bottle) that was labeled "after douching." Needless to say that one wasn’t opened! Neither were the vacuum cleaner bags, as they usually contain pesticide-laden dust from over treated carpets for these so called pests.

All of these cases have had several symptoms in common. The 'critters' typically fly through the air, crawl on the skin, frequently appear and disappear in the skin, make clicking noises and can be found in soap and toothpaste. Generally, inflicted individuals have gone to several medical doctors to no avail and can almost never be persuaded that the pests are imaginary.

Treatment of Symptoms. Normal treatment for bedbugs bites, if any, consist of application of a variety of means to relieve the itching. Systemic corticosteroids for treating the itching and burning often associated with bedbug bites in many cases are less than effective. Antihistamines can reduce itching in some cases, but typically do not affect the appearance and duration of the lesions. Topical corticosteroids, such as hydrocortisone, reportedly are effective in reducing lesions and decreasing the associated itching.

Application of heat (blow-dryer, hot washcloth, hot water)) can be effective in relieving itching and inflammation for several hours. The water temperature should be about 50 °C (120 °F), or this procedure may aggravate the symptoms. To avoid scalding the skin, this treatment should only be self-administered.

Conventional insect repellents, like those containing DEET used to deter ticks and mosquitoes, do not appear to be effective against bedbugs. Attempting to avoid being bitten by applying insect repellent at bedtime is not recommended. Sleeping with the lights on is not likely to deter hungry bedbugs either. 

 

Means of Home Infestations. There are a number means by which a home, business, hotel or other structures can become infested with bedbugs. One common way is to pick them up while traveling or when staying in hotels, bed-and-breakfasts, hostels, or motels.  These locations are typically associated with a high risk of bedbugs infestations due to their rate of turnover and continual influx of temporary residents. Once acquired the now hitchhiking bedbugs may then be transported and brought back to the homes of the guests in their luggage, brief case, jacket or any other items.

Furniture rentals and purchases of used furniture are rather common, especially in poor communities, and this probably helps rapid and repeated spread of bed bugs to new sites and redistribution of them back into places from which they may have previously been eliminated.

Large multi-unit buildings can be very difficult to rid of bed bugs. Bedbugs infest a new residence by traveling between multi-unit housing such as condominiums, dormitories, and apartment buildings, or arrive after having exited infested furniture that has been thrown out, discarded and/or placed outside for garbage collection or for treatment. This unintentional spread between adjacent home sites and nearby units is dependent, in part, upon the degree of infestation at the source (i.e. a heavier infestation is more likely to spread), but also upon the building material used to partition units and the material used to seal connecting pipes, vents, wires, etc. Further potential to spread is also directly related to the manner in which infested items are disposed of—such as whether or not contaminated furniture is dragged through common areas while being removed.

Once they become established, any control effort that does not include concurrent inspection of all units, together with a coordinated program of treatment and occupant education, is usually doomed to fail. The bugs will frequently move from any partially treated, potentially repellent active site to adjacent rooms or floors. They readily move through wall voids, along utility lines, heating ducts, elevator shafts, and laundry or mail chutes

Bedbugs can also be acquired through bringing infested furniture or contaminated, used clothing into a household. One of the worst things a person can do is pick up and use a used piece of furniture that has been discarded.  It is not uncommon for someone to  discard a perfectly good piece of furniture that has a bed bug infestation. Furniture does not necessarily have to have been previously owned or discarded—as even brand new furniture can be exposed to bedbugs during storage or in delivery vehicles.

A big problem is delivery trucks.  A good example would be someone buys a new bed.  It is delivered by a delivery system that in turn picks up the old bed in the same truck.  What are the chances of that old bed having bedbugs or at least some of the hundreds of mattresses that truck has picked up having bedbugs.  Sooner or later that truck is going to be infested with bedbugs. It only takes one impregnated female which is capable of depositing 200 or more eggs to start a new infestation.   Back in the 40’s it was not uncommon to treat such vehicle for bedbugs.  I am not sure the industry is at that point yet.                                                                                      

In locations that are severely infested, bedbugs may actually crawl onto a person's clothes and be carried from location to location.  It is also common for bedbugs to nest in clothing articles that are generally not frequently washed and for them to then spread when such apparel is either stored publicly with other apparel (as in locker rooms and on coat racks). Otherwise, bedbugs will not be usually carried from place to place by people on the clothing they are currently wearing. General machine washing and drying on high heat will kill all stages of bedbugs.

The size of a bedbug infestation can range from a few to thousands, or even tens of thousands. A single bedbug brought into a home has a potential for reproduction with its resulting offspring then breeding and potentially leading to a geometric progression of their numbers.  In any case, bedbugs reproduce prolifically and it is not at all unusual for exterminators to encounter thousands of bedbugs in even a single mattress. Sometimes people are not aware of the insects and do not notice the bites. The visible bedbug infestation does not represent the infestation as a whole, as there may be infestations elsewhere in a home and the sighting of one bedbug typically means that there may be many more in hiding. However, the insects do have a tendency to stay close to their hosts, hence the name 'bed' bugs.

Steps to Minimize the Chances of Bringing Bedbugs into a Structure.

The first step is to be aware where one is likely to encounter a bedbug infestation.  This will include any place with a high turnover of people spending the night—hostels, hotels near airports, and resorts—are most at risk. But the list continues… apartments, barracks, buses, cabins, churches, community centers, cruise ships, dormitories, dressing rooms, health clubs, homes, hospitals, jets, Laundromats, motels, motor homes, moving vans, nursing homes, office buildings, resorts, restaurants, schools, subways, theaters, trains and  used furniture outlets.  Bed bugs don’t prefer locations based on sanitation or people’s hygiene. The critical component for their survival is food, or put more simply our blood.

Bed bugs and their relatives occur nearly worldwide. They became relatively scarce during the latter part of the 20th century, but their populations have resurged in recent years, particularly throughout parts of North America, Europe, and Australia.

Most stay near where people sleep, hiding near the bed, a couch or armchair (if that’s where you snooze)—even cribs and playpens. Their flat bodies allow them to hide in cracks and crevices around the room and in furniture joints. Hiding sites include mattress seams, bed frames, nearby furniture, or baseboards. Clutter offers more places to hide and makes it harder to get rid of them. Bedbugs can be found alone but more often congregate in groups. They’re not social insects, though, and don’t build nests.

 

Traveling greatly increases the chances of someone bringing bedbugs home.  As a result travelers should learn about how to avoid this possibility. Always inspect before settling into any room. Pack a flashlight (even the keychain LED variety) and gloves to aid in your inspection. The inspection should focus around the bed. Start with the headboard, which is usually held on the wall with brackets—lift up 1 – 2 inches, then lean the top away from the wall to gain access to the back. If you’re traveling alone, someone on staff should help. After checking the headboard, check sheets and pillows for blood spots. Next, pull back the sheets. Check the piping of the mattress and box spring. Finally, look in and under the drawer of the bedside table. If all these places are clear, enjoy the night. The next morning, look for blood spots on the sheets—bed bugs defecate soon after they feed.

If you find evidence, but no live bed bugs, the evidence may be old and doesn’t mean that the hotel is dirty. Tell the front desk discreetly what you found and ask for another room—one that doesn’t share a wall with the room you just vacated. Bed bugs are a PR nightmare for the hospitality industry. If you run to a competitor (who’s just as likely to have bed bugs) it makes it less likely that the industry will become more open about this issue. Communication is key. Ideally hotels and motels would pride themselves on their bed bug programs and show customers how to inspect to keep all parties bed bug free.

If you can avoid it, don’t unpack into drawers and keep luggage closed on a luggage rack pulled away from the wall. Never set luggage on the bed and keep it closed especially at night. Similarly do not leave cloth laying around the room at night.

Launder your clothes before or as soon as these items are brought back into the home. If you found bed bugs after moving into a hotel room, you could ask the hotel to pay for laundering—and for steam-cleaning your luggage. The hotel may refuse, but it’s worth asking. Regardless, once home you should unpack on a floor that will allow you to see bedbugs—stay off carpets! Unpack directly into plastic bags for taking clothes to the laundry. Suitcases should be carefully inspected and vacuumed.

Bedbugs and Disease. Bedbugs appear to possess all of the necessary criteria for transmitting diseases, but there have been no known cases of these pests vectoring or transmitting any disease. Bed bugs have been found naturally infected with at least 30 human pathogens but have never been proven to transmit any of them biologically or mechanically. There are some indications that bedbugs may be a vector for hepatitis B  and, in endemic areas, for American trypanosomiasis (Chagas disease). Of note, reports have indicated the risk of insect transmission of HIV, if any, is extremely low and likely nonexistent. Therefore from a disease transmission standpoint bedbugs are considered less dangerous than some more common insects such as the flea.

as well as proposed control strategies and techniques. Education may include verbal explanations, answering questions, posting notices, broadcasting notices, postings on web sites or distributing handouts in the local language. Throughout a control program, continuous communication should be maintained between occupants, building managers, PMPs and any involved government agencies.

Physical removal. Bed bugs can be vacuumed from exposed harborages or resting sites, such as box spring edges or mattress seams, but their eggs are stuck tightly to harborage surfaces and are usually hard to remove. Using a high efficiency particulate air (HEPA) filtered vacuum, which removes >99% of all particles >0.3 micron diameter, will ensure that many allergens associated with bed bugs and their debris are also removed. Vacuuming, especially during inspections, will immediately remove a significant portion of the pest population and will usually kill some of the bugs. Bed bugs may also be removed from exposed resting sites by pressing down on them with the sticky side of any commercially available tape, hand-picking them, or brushing them directly into a container of rubbing alcohol or soapy water (Potter 2004, Gooch 2005). For cimicids that feed chiefly on bats or birds, it is essential to completely remove all host nest materials followed by thoroughly applying some appropriate control action (e.g., heat) or product (e.g., a properly labeled insecticide) at and immediately around every prior nest sit

 

FAMILY-LARGIDAE-LARGID BUGS

 

This is a very small family of large bugs.  Very little is known about this family of plant feeding forms.  There are no largid pest species in North America.  Because this is such a small family, identification can be based on overall appearance.

  The most commons species of largid bug in the US.

 

FAMILY- COREIDAE-COREID BUGS

 

In the case of the coreid bugs and other closely related families (Corizcidae, Rhopalidae), the membrane of the hemelytra has many simple veins-more than the 4 or 5 as in the Lygaeidae.  Many of the Coreidae have a flattened hind tibia and are referred to as leaf-footed.

 

   

 

                                                                                             A coreid bug with many veins in the hemelytron membrane.

 

        

 

                A coreid bug with hind tibia flattened and leaf-like in appearance.  Image courtesy of R. Scott Cameron-International Paper.

 

       The most damaging of the coreid bugs in North America is the squash bug, Anasa tristis, a common pest of melons, gourds, squash and pumpkins.  This bug injects a toxic material when feeding and can cause a burning and shrinking of vines.

 

 

The squash bug.  Image courtesy of ARS.

 

  FAMILY-CYDNIDAE-BURROWING BUGS

 

This is a very small family of small to medium sized bugs.  They are typically black, flattened and possess flattened tibia armed with well-developed spines (arrow) on all legs.  They are normally found under rocks and burrow in the soil around roots of plants, especially grasses.

 

            

 

              A burrowing bug.  Arrow indicates tibia armed with strong spines

 

FAMILY-ALYDIDAE-BROAD HEADED BUGS

 

This family is closely related to and sometimes lumped in with the coreid bugs.  It can be distinguished from the former in that the head is at least as wide as the prothorax, while in the coreids it is distinctly narrower.  There are no economic forms of concern in the US.  Alydids are very common in many tropical countries.

      

 

A broad headed bug illustrating head as wide as thorax. 

 

FAMILY-RHOPALIDAE-SENTLESS PLANT BUGS

 

This is another family that is closely related to the coreids.  The distinguishing characteristic that can be used to separate these two families is that, as their name implies, Rhopalids do not produce a distinct odor when disturbed.  Morphologically this can be determined by the presence or absence of a scent gland that appears  externally as a slit like structure located on each the side of the mesothorax.

The Box Elder Bug or Maple Bug is found primarily on boxelder trees, as well as maple and ash trees . The adults are about 12½ mm (½ in) long with a dark brown or black coloration, relieved by red wing veins and markings on the abdomen. Nymphs are bright red.

They may form huge colorful aggregations while sunning themselves in areas near their host plant (e.g.rocks, shrubs, trees, and man-made structures). However, their presence can frighten and annoy people, thus they are considered nuisance pests. This is especially a problem during the cooler months, where they sometimes invade houses and other man-made structures seeking warmth or a safe place to overwinter. They remain inactive inside the walls (and behind siding) while the weather is cool, without doing any damage to the building.

When the heating systems revive them, some may falsely perceive it to be springtime and enter inhabited parts of the building in search of Acer or Koelreuteria seeds, water, and conspecifics (many of which they are unlikely to find in a building). In the spring, the bugs leave their winter hibernation locations to feed and lay eggs on maple or ash trees; aggregations may be seen during this time and well into summer and early fall, depending on the temperature.

These insects can be killed with a dilute mixture of soap and water — 2 tablespoons per gallon — sprayed on them directly. This procedure can stain or discolor siding however. Natural insecticides have also been proven to be very effective in killing these bugs and eliminates the possible damage to siding. A small strip of duct tape can also be an effective way of killing these insects, as they seldom will fly away when approached. Unable to escape from the adhesive backing, they can then be disposed of. They can also be kept out of the home, to a degree, by putting boric acid and/or diatomaceous earth in places they would gather to enter, as well as by using weather stripping and other means to seal the house better.

The best way, however, to eliminate and prevent them is to hire a professional to treat the outside of your home.  They will put a residual down on the outside of the home that will not only eliminate current bugs crawling on the outside, but will kill any future boxelders that land on your home.  The best times for this treatment is spring and fall when the boxelders are most active.

   Citric (especially orange) based disinfectants have been found quite effective to clean the areas where they congregate, keeping them away

 

 The box elder bug, a very common species.  Image courtesy of Clemson University Entomology.

 

FAMILY-PYRROCHORIDAE-PYRROCORID BUGS

 

Members of this family are commonly referred to as the stainers.  Distinguishing characteristics are that they lack ocelli and are frequently bright red or orange.  Their color patterning and body shape is fairly consistent from species to species.  This group is well represented in tropical countries of the world with several economic forms occurring in the southern US.  The cotton stainer is of concern feeding on cotton and citrus.  On cotton they puncture the immature bolls feeding on seeds and stain the lint with their exudates.  In citrus they puncture the fruit and suck it dry.

 

 

 

 

 

 

 

 

 

   

 

                                                                                                                 

 

                            

                                             

 

 

                                                                                                                    Typical pyrocorid bug.

 

FAMILY-MIRIDAE-PLANT BUGS

 

This is a group of common medium sized bugs most of which suck the juices of leaves, stems or fruit. Many are host specific with relatively few true pest species, considering the size of the family.  There are some species of this family that are considered important predators in cropping situations.  The most diagnostic characteristic of the family is the presence of a cuneus, which is a separate section of the leathery part of the hemelytra.  The cuneus is the small triangular portion of the leathery wing located in the distal outer margin (orange arrow).  In addition the membrane of the hemelytra has two enclosed cells.

 

                                                                                          

                                                                                                            Lygus Species.  Image courtesy Entomart.

 The genus Lygus includes over 40 species of plant-feeding insects. At one time, nearly 200 species were classified as genus Lygus, but most of those have since been reclassified into new or existing genera. The term lygus bug is used for any member of genus Lygus. The more well-known lygus bugs are those that have agricultural impacts. Some lygus bugs are very serious agricultural pests.

The insects appear as small oval creatures. Adult lygus are approximately 3 mm wide and 6 mm long, colored anything in a range from pale green to reddish brown or black. The bugs can be solid shaded or mottled, and have a distinctive triangle or V-shape on their backs. Adults are capable of flight, and will often thus escape when approached. Nymphs are wingless, and being light green in color, are often mistaken for aphids. However, lygus nymphs have harder shells, are typically more active, gain spots as they age, and lack aphid abdominal tubes.

Lygus bugs are known for their destructive feeding habits - they puncture plant tissues with their piercing mouthparts, and feed by sucking sap. Both the physical injury and the plant's own reaction to the bugs' saliva cause damage to the plant. The females insert their eggs directly into the plant tissues using piercing ovipositors, and the newly emerged nymphs are voracious consumers of plant tissue juices. Signs that a plant has been attacked by lygus bugs include discoloration, deformation of shoots and stems, curling of leaves, and lesions on the plant tissues.

§                                                                                                                                                                                                                                                                                The tarnished plant bug (Lygus lineolaris) feeds on over half of all commercially-grown crop plants, but favors cotton, alfalfa, beans, stone fruits, and conifer seedlings. This bug can be found across North America, from northern Canada to southern Mexico.

§                                                                                                                                                                                                                                                                                The western tarnished plant bug (Lygus hesperus) is a very serious pest of cotton, strawberries, and seed crops such as alfalfa. In the state of California alone the bug causes US$30 million in damage to cotton plants each year, and at least US$40 million in losses to the state's strawberry industry.

§                                                                                                                                                                                                                                                                                The European tarnished plant bug (Lygus rugulipennis) is distributed throughout Europe, where it will feed on over 400 types of crop plant from peach trees to wheat to lettuce.

Some methods of biological pest control have proved useful against lygus bugs. For example, wasps of the genus Peristenus are parasitoids of lygus bugs; an adult wasp will inject an egg into a lygus nymph, and once the egg hatches the wasp's larva will consume the nymph from the inside out.

 

50.                                                                                                                                                                                                                                                                                      One of the easiest means of identifying an aquatic true bug is by the presence of tiny hair-like antennae which are hidden beneath ridges in the front of the head.

51.                                                                                                                                                                                                                                                                                      In some species of giant waterbugs the female deposits the egg on the back of the female.

52.                                                                                                                                                                                                                                                                                      Backswimmers swim with the most lighted part of their environment on the underside, or venter, of their bodies.

53.                                                                                                                                                                                                                                                                                     With water boatmen the tarsal claws are antapical referring to the fact that they are positioned on the last tarsal segment before the tip and are capable of being retracted.  This allows them to walk on water.

54.                                                                                                                                                                                                                                                                                      Assassin bugs are characterized by possessing a short beak, which terminates in a groove in the front part of the thorax.

55.                                                                                                                                                                                                                                                                                      Most members of the Pentatomidae are phytophagus, chiefly feeding on seeds and fruiting bodies

56.                                                                                                                                                                                                                                                                                      Minute priate bugs are primarily predatory.

57.                                                                                                                                                                                                                                                                                      Damsel bugs are commonly found in many crops and are considered an important predator.

58.                         The bed bug is considered an important vector of several diseases of humans.

59. Bed bugs are only able to detect these host cues over short distances (about 3 feet away for CO2 and even less for heat).

     60. One of the possible reasons for the current increase in bedbug problems in the US is the change from using residual insecticides for cockroach control to the use of baits.