The term "bug" is used by the general public to refer to any one 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, waterbugs, mealybugs). When used alone by entomologists, this term refers to insects from the order Hemiptera. The term 'true bugs' is sometimes used to distinguish insects of this order from those in other orders.
One of the unique characteristics of Hemiptera is the structure of the front pair of wings. In most hemipterans, the inner half of the front wing is thickened and leathery, while the outer half is thin and membranous. The derivation of the word Hemiptera refers to this structure (hemi = half, ptera = wing).
True Bugs Illustrating the Half Leathery.
An additional characteristic of this order is piercing-sucking type mouthparts. In this case the mandibles and maxillae have evolved into elongate, needle-like structures for piercing the host and sucking its juices. The needle-like structures form a beak which rises from the front of the head. This latter characteristic is often used to distinguish the Hemiptera from the closely related order of the Homoptera that also possesses piercing sucking beaks (Homopteran beaks arise from the back of the head behind the eyes).
Assassin Bug’s Piercing-sucking Mouthparts that Rise from in Front of the Eyes. Image Courtesy of Peter Chew, Brisbane Insects
Giant Waterbugs. This family contains the largest bugs in the order Hemiptera, some of which may reach a length of 3 inches in the United States, and approach 6 inches in South America. Nearly all are elongated and oval in shape, tan to brown and possess large raptorial front legs.
Common Giant Waterbugs. Images Dr. Kaae.
Commonly they are found in lakes, streams and ponds, where typically they 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 quite capable of delivering a painful bite, if handled carelessly.
One year at Cal Poly we decided we were going to put together an aquarium with all types of aquatic insects. We collected dragon fly immatures, water striders, backswimmers, water boatmen and a variety of other aquatic insects including 6 giant waterbugs. A few days after everything was in the aquarium I noticed that there were almost no other insects other than the giant waterbugs. A few days later there was only one giant waterbug-a disappointment but an example of how vicious these predators are. Not to give up we recollected everything but decided to cut the beaks off the giant waterbugs. Several days later same result-one giant waterbug. I don’t know how this was accomplished because the bugs had no mouthparts-must have gummed them to death!
Another example of the aggressiveness of these insects occurred in a swimming pool in Acapulco. I dove into the large pool which contained one giant waterbug-it found and bit me. It now is on a pin in our museum at Cal Poly.
Giant waterbugs frequently leave the water to feed and are readily attracted to lights. They also have been called the electric light bugs and toe biters. In some California species the female lays her eggs on the back of the male which carries them around until hatching. As in several groups of aquatic Hemiptera, a giant waterbug 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.
As one might expect, giant waterbugs are a source of human food. It came as no surprise while shopping in the day market in Chiang Mai, Thailand, that we found a giant waterbug stall next to the chicken and egg stalls. The vendor had a large basket containing approximately 80 three-to-four inch long giant waterbugs. Each of the bugs’ legs and beaks were tied down with a rubber band to prevent them from escaping or biting. Apparently these bugs are used to make a spicy sauce to be served over rice or they are eaten whole. They are collected from the rice fields.
Water Striders. The water striders are long-legged insects that run or skate over the top of water to catch their prey, which are mainly other insects that fall accidentally onto the surface.
Group of Water Striders Feeding on an Insect that has Fallen to Water. Image Courtesy Fritz Geller-Grimm CC BY SA 2.5
The front legs are short and raptorial for catching and holding prey while feeding. The tarsi of these insects are covered with short hairs that are difficult to wet. The tarsal claws are antapical. That is, they attach to the last tarsal segment before the tip of the leg and are capable of being retracted. Therefore the claws do not break the surface tension of the water and the non-wettable hairs allow the insect to walk on water. These insects are common in quiet water where they often occur in large numbers.
Mating Pair of Water Striders Illustrating How They Dent the Water due to the Non-wettable Hair on their Legs. Image Courtesy of Markus Gayda Creative Commons. SA 3.0.
Some individuals of a species are winged and some are apterous (no wings). 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 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.
Assassin or Kissing Bugs. This is a large group of moderate-to-large-sized bugs (1/2 to 2 inches long)) and is characterized by a short beak, which is slightly longer than the head. Also the head narrows behind the eyes, giving it a neck-like appearance.
Top. Blood Sucking Assassin Bug. Image Dr. Kaae. Bottom. Predatory Assassin Bug. Image Courtesy Peter Chew, Brisbane Insects.
Most species are predatory on other insects, but some feed on the blood of humans and other warm-blooded animals. The predatory forms are considered beneficial but can also inflict a painful bite if handled. Assassin bugs kill their prey by injecting a venomous salivary fluid with their beak. They may also use their beak in defense. In some cases the bite has been compared to that of a venomous snake. The pain can be intense, with other symptoms that include general swelling, faintness, vomiting and nausea that can last weeks or occasionally months. The bites of the blood-sucking species are not felt initially because the saliva of these forms contains an anesthetic. It also contains an anticoagulant to insure blood flow but after a few hours large, red swollen blotches frequently develop. There is one African species that uses its beak as a spray gun. It ejects its saliva in a series of short, aimed squirts of a distance of up to several feet, thereby holding potential predators at bay.
One species in the genus Apiomrus, in addition to possessing a toxic bite has a number of additional defensive mechanisms. It collects plant resins from a common roadside weed. The resins are quite sticky with a strong repulsive odor and serve as a natural defense to protect this plant from phytophagus insects. The adult female assassin bug collects these droplets of resin from the plant by scraping them off with her front legs but eventually transfer them to her body. During oviposition she coats each egg with copious amounts of resin. The end result is a tight cluster of eggs that are coated on the outside by a thick layer of resin which serves as a deterrent to ants, other insects and possibly protective to microbial pathogens. Upon hatching the new nymphs collect the resin from the outside of the eggs with their front legs. Of course, the resins may again serve as a deterrent to potential predators, but they also are used as an aid in capturing prey. As already indicated, many predatory insects use their front legs to capture their prey. In this case, the addition of sticky resins to the forelegs aids them in holding their prey.
A Species of Assassin Bug Coated with Resin. Image Courtesy entomart
From 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 (this is mainly due the fact that this is the area of the body area that is not covered by a blanket while sleeping). In Central and South America, kissing bugs can vector Chagas disease, a highly fatal disease in humans. Darwin was thought to have contracted this disease on his travels to these countries.
As indicated many of the predatory assassins pack a powerful bite. One of our students was bitten on the finger by a rather large assassin bug while we collecting insects on a trip to Thailand. Unfortunately she had a ring on that finger, which began to swell quickly. The swelling got so bad that the ring cut off circulation to her finger, which she could have lost. Fortunately the emergency room at the local hospital was able to cut off the ring in time. She still has all her fingers!
Water Boatmen. This is the most common group of aquatic insects in North America, both in number of species and abundance of individuals. The water boatmen 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 brown to dark gray in color. The hind legs are elongate and oar-shaped, while the front legs are scoop-shaped and used to scrape algae (their main diet) off rocks.
A Common Species of Water Boatman. Image Compliments of Charles Hogue, L. A. County Natural History Museum.
Because the insects are so common in aquatic situations and are a primary converter of plant-to-animal matter, they are considered quite important in food chains. In many areas of the world water boatmen are even consumed by humans. The adults normally are not consumed, as they are too crunchy; however, in the lakes of Mexico, large rope mats are placed in the water which serves as suitable substrate for laying eggs. Periodically these mats are removed and the eggs are scraped off and ground into protein based flour.
Backswimmers. As you might expect, these are so named because they swim on their backs. They are 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 with most resting 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 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 underside (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.
A number of years ago I had a swimming pool in the backyard of my old house. Unfortunately I could not get the right amount of the chemicals (essentially bleach) correct that had to be added to prevent algae from becoming established in the pool. As a result the pool took one a green color (due to algae). Well, when pools develop algae eventually mosquitoes are attracted that subsequently lay their eggs on top of the water. Once hatched the developing mosquito larvae (wrigglers) feed on the algae and develop in the water. In California there are governmental agencies (Vector Control) that function to minimize mosquito breeding. One of the ways they do it by aerial photography-flying over neighborhood looking for green pools. Sure enough after a while a worker from Vector Control showed up at my house and indicated “you are breeding mosquitoes in your swimming pool”. I replied “lets go back out and check it out”.
He didn’t know who I was. We looked at the pool and he immediately indicated “You are breeding mosquitoes, those are mosquito larvae.” I responded what instar. An instar refers to the different sized larvae that develop to reach the pupal stage. I asked “Do you see any pupae or adults”. He didn’t know what an instar was but he answered no. My answer to that was that technically I was not breeding mosquitoes. I asked him if he knew what I was pointing to-referring to any of a number of backswimmer that had flown into the pool and were actively feeding on the mosquito larvae. I subsequently pointed out water striders, water boatmen and a few other mosquito predators that were abundant in the pool. I had this whole ecosystem of insects that had been attracted to the pool and were feeding on the mosquito larvae. I indicated that the mosquito larvae were under good biocontrol and would never reach the adult stage which is of course the stage that causes problems-bites. He indicated that he would be back (2 weeks later-same situation). He eventually gave up. At some point I gave up on the pool and made a large planter out of it.
Other Hemiptera-Just Because Their Cool Looking.
Lace Bugs. Nymphs and Adults. Phytophagus. Courtesy Entomart.
Top/Left. Water Measurer. Semi-aquatic Predator. Courtesy entomart. Top/Right. Toadbug. Semi-aquatic Predator. Image Dr. Kaae. Bottom. Assassin Bug. Predator. Courtesy Peter Chew. Brisbane Insects
The common bed bug (Cimex lectularis) is the main species that is currently found infesting buildings and homes throughout the United States. There are a number of other species of bedbugs found around the world. These are more frequently associated with birds and bats and have been found on occasion in homes when these animals have been nesting on/within a structure. The tropical bedbug, Cimex hemipterus occurs throughout tropical areas of the world thus preferring higher temperatures and humidity than Cimex lectularis. In Europe and the United States, well-established infestations of this species are quite rare; in the Western Hemisphere, it is seldom found north of Puerto Rico and Mexico, or south of Brazil and Peru. Occasional limited populations have been found in Chile and Florida. Other species of bedbugs, including swallow bugs, bat bugs, and other bird-feeding bugs occur in various temperate parts of the world. On occasion they may bite humans and are found sporadically in or around structures and homes.
Cimex hemipterus occurs primarily in more tropical areas but has been found in temperate areas of the U.S. This is especially so when people have engaged in international travel. Bedbugs have been known by a variety of names including mahogany flat, wall louse, crimson rambler, chinch, heavy dragoon and redcoat.
Left. Bedbug with Piercing Sucking Mouthparts Inserted into Host (Human) Sucking Blood. Piercing Sucking Mouthparts of Bedbug. Both Images Courtesy CDC.
Identification. Adult are reddish-brown, flattened critters that are about 3/16" long and up 1/8" wide. After feeding on blood, bedbugs increase considerably in size and are swollen and dull red in color. Their eyes are deeply pigmented and the sides of the flattened collar-like pronotum curves somewhat around the head. The immatures (nymphs) vary considerably in size and are basically colorless (unless recently fed) with the first instar nymphs about the size of a period in this article. Bedbug eggs are white, oval in shape and about 1 mm long (very difficult to see with the naked eye). Adult tropical begbugs are approximately ¼ larger than the common bedbug.
Bedbug History. It is thought that bedbugs were originally ectoparasite of bats living in caves but subsequently changed hosts to include humans (cavemen) occupying in the same habitat. These pests are mentioned in medieval European texts and in classical Greek writings back to the time of Aristotle. It is believed that these bugs were originally imported into the U. S. by early Europeans. There are colonial records of the early 18th century where passengers were prohibited from bringing bedding material on ships. During the early 1900s, bedbug infestations were quite common in American homes. At that time, they were rated amongst the top structural pests with an estimated 1/3 of all residences infested at some point in time. However, with the discovery and use of DDT and other insecticides in and around homes, these pests quickly disappeared. The effectiveness of these chemicals was mainly due to their long residual activity. As invariably occurs, with the overuse of pesticides, bedbugs developed resistance to DDT after a few years, but other chlorinated hydrocarbons and organophosphates (malathion) were used to keep these pests at a low level. Again the main factor why these chemicals were more effective in controlling bedbugs than modern chemicals is persistence. For example, DDT when sprayed on a bed remains active for up to one year. On a wall, this chemical can remains active even longer. With this residual activity, a bed bug that came to feed on a sleeping person was eliminated, and since they all need to feed at one time or another, the infestation was eventually eliminated.
In many undeveloped countries, bedbugs remained and still remain important pests. In the past 10 to 15 years, bedbugs have made a huge comeback in many areas of the world including all 50 states as well as Puerto Rico, Guam, American Samoa, Australia, Canada, parts of Europe and Africa.
In the U. S., many of major cities are presently experiencing considerable bedbug infestations. These include Los Angeles, San Diego, San Francisco and New York. Some cases have escalated to extreme levels resulting residents to label the infestations "house herpes". In California, one of the large companies that utilize bedbug dogs to detect infestations reported that they had a mere 12 searches 10 years ago. A couple of years later, the same company reported 33,000 searches. The National Pest Management Association recorded a 71% increase in bedbug calls between 2000 and 2005. Twenty five percent of the North Carolina 700 plus hotels surveyed between 2002 and 2006 required bedbug treatment. These statistics remain similar today.
Why the Increase. There are several possibilities why this major increase has occurred. One possible reason is a tremendous increase in worldwide travel. Now people commonly travel to and from all parts of the world. This includes many countries and areas where bedbugs are common. Also included are leisure and business travelers who commonly move between continents. In addition, countries are increasingly multicultural with residents traveling back and forth from their homelands. Of course, bedbugs are great hitch-hikers and easily travel in luggage, cars, busses, cruise ships, airlines and trains.
Another possible reason is the significant increase in illegal aliens and other temporary workers 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 and in low-income apartments. It is fairly common for these individuals to readily change or leave residences for new jobs or for them to return to their home country. These conditions can quickly lead to importation and movement of bedbugs.
Thrift shops, second-hand stores, swap meets, antique stores, flea markets, and Goodwill stores are on an increase in the U.S. This is especially true with the present economic crisis. Any used item is a possible source of a new infestation. Very frequently residents will throw out furniture in attempts to rid their home or apartment of these pests. A nice sofa, chair or even new looking bed is far too attractive to some to let the trash man carry these away.
There apparently are geographic hot spots of these pests. Reportedly, there were at one point 3 apparent U. S. epicenters at poultry facilities in Texas, Arkansas, and Delaware. In these cases, workers in these farms were spreading bedbugs and unknowingly transporting them from the facilities to their residences and elsewhere.
Also changes in pest control techniques and the development of resistance to commonly used pesticides (pyrethroids) has certainly added to the reestablishment of the pests in the U. S. In the past, cockroaches were controlled by crack and crevice treatment in homes, hotel rooms, low income housing and other indoor locations. As a result, bedbugs were simultaneously controlled with these pesticides. However, during the mid-1990 there were major changes in these practices. Treatments of baseboards in motels, hotels, apartments and homes were replaced with the use of baits for ants and cockroaches. Obviously bedbugs don't feed on baits as they are blood suckers. In this absence, bedbugs were able to travel safely from the luggage or other locations--hence the beginning of the problem. It is of importance to note that once the bedbug problem developed, there were few effective pesticides available that had the residual activity needed to control these pests. Many professionals point out the dramatic rise in activity of this pest occurred approximately 10 years after applicators stopped spraying for cockroaches.
Biology. Since the common bedbug in the U.S. feeds on human blood at night (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 the victim's breath and body heat. However, they are only able to detect these host cues over short distances. This distance is about 3 feet away for CO2 and even less for heat. It is not well-understood how they are capable of finding a person in a bed when 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 the case in heavy infestations. In such cases, many ultimately 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 of these insects are tiny, whitish, and somewhat difficult to detect on most surfaces (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 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 and in or near crevices where bedbugs hide. At temperatures above 21°C (70°F), eggs hatch in about 10 days. At lower temperatures hatching may take as long as 28 days.
Left. Over 1,000 Bedbug Eggs (hatched/unhached), Cast Skins (empty Exoskeletons from Molted Nymphs) and Living Nymphs on Single Couch. Right. One of 30 Pockets of Bedbugs on Single Bed. I Counted Over 50 Live Bedbugs in This Pocket. Estimated Overall Live Bedbug Population Around 1,000. Individual Bitten for Several Months. The Black on Image is Bedbug Feces-Gross! Also Note the Clear Cast Exoskeletons. Images Dr. Kaae.
Under ideal conditions, the survival rate of bedbug eggs is approximately 97%. Even under optimum conditions, some nymphs will die prior to reaching the adult stage. This is especially true with the first instars. They are particularly vulnerable due to their small size and relatively large surface area. 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 survival is good under favorable conditions, and 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, presence of a host), a bedbug 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 6 to 9 months. However a recent laboratory study has shown that starvation has a negative impact on bedbug 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. 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. 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, bedbugs are cold blooded. This means they take on the temperature of their surrounding environment. Correspondingly, the cooler the surrounding environment, it takes them longer to complete their 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. These are an airborne aggregation pheromone that attracts the bedbugs to the location and an arresting pheromone that causes them to settle. Although they normally venture 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 down to their host.
Aggregation of Bedbugs. Image Courtesy A.L. Szalanski, 200 GNU Free Documentation.
Mating. The mating behavior of bedbugs is at times quite competitive and strange. Males inject their sperm into the female by puncturing (penetrating) the body wall as the female lacks a natural opening for reception of his sperm. The sperm then swim throughout the female’s body cavity eventually finding and fertilizing her eggs. Apparently this is not limited to females, and occasional males are found with copulation scars where other males have penetrated their body wall. This apparently happens when a male penetrates another male that is copulating with a female and subsequently 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. This can occur when attack by a predator and to discourage other males who attempt to mate with them.
Bedbugs in Traumatic Insemination. Image Courtesy of Rickard Ignell Swedish University of Agricultural Sciences CC BY SA 1.0.
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 by their feeding on the occupants. The bug pierces the skin with 2 hollow feeding tubes. One of the tubes functions to inject saliva which contains anticoagulants and anesthetics, and the other tube withdraws the blood of the host. The anticoagulant serves to prevent blood from coagulating the tiny tube-like mouthparts, and the anesthetic serves to numb the area and prevent detection of their presence. These injected chemicals are protein based and the body reacts 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 individuals, the bite of a bedbug cannot be felt until minutes, hours or even weeks later. Of course, the first indication of a bite usually occurs from the desire to scratch the bite area. It is not unusual to have been bitten many times before symptoms occur. For this reason plus their secretive behavior, an initial infestation may not be detected for some time. One estimate is that it will frequently take 3 months for an initial infestation to develop to the point where it is detected by the victim. In many cases, repeated exposure to bedbug bites leads to more severe skin reactions. In one report, 18 of 19 victims experienced a skin reaction after bedbug exposure, but usually only after repeated exposures over time. With repeated exposures, the period between initiation of the bite and the visible skin reaction decreased from about 10 days to a few seconds. However, there are no typical skin reactions to bedbugs feeding on a person. The symptoms may vary considerable due to a number of factors, including, but not limited to number of bedbugs present, duration of the infestation, previous exposure, individuals physiological reaction to feeding, species of bedbug and differences in skin type of the person bitten.
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. 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 and 48 Hours.
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 welts, itching or other skin abnormalities are not a reliable symptom of the presence of these pests. Even dermatologists do not possess the ability to diagnose a bedbug bite. 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 receive many “false alarms” about bedbug infestations. Cosmetics, allergies, medications, drugs and environmental contaminants all can produce reactions similar to insect bites. There are 4 general categories of conditions that can cause skin irritations of skin, namely biting arthropods (e.g., insects or mites), environmental factors, health related conditions and personal use products.
Arthropod Bites Confused with those of Bedbugs.
Mosquitoes. 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 or more to appear while those of mosquitoes are typically immediate.
Image Courtesy CDC
Fleas. Typically bedbug bites do not have a red dot in the center that is commonly characteristic of flea bites. The red dot is merely due to the fact that fleas have larger mouthparts than bedbugs. A trait shared with flea bites is tendency towards the pattern of sequential bites often aligned in rows of three of more. 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 bite a dog or cat rather than humans. Obviously timing as to when bites occur is an important consideration. If someone goes to bed and has multiple the next morning when they wake up, the likely culprit is bedbugs.
Right. Image Courtesy Katja ZSM. CC BY-SA 3.0
Spiders. A common complaint is spider bites. In actuality, spiders 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 that correspond to their paired fangs. Spider bites almost never occur in large number on any one individual. Also the fangs of most spiders are not large enough to bite humans
Image Dr. Kaae.
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. On occasion this spider does not inject venom with a bite resulting in very minimal symptoms.
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. Biting mites are also found on mice or rats. When a bird or rodent dies (or the young leave the nest), hundreds 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 and causes intense itching and irritation. Skin between the fingers, the bend of the elbow or knee, and the shoulder blades are areas most often affected by the presence of scabies. The intense itching is accompanied by a rash. A distinct symptom of scabies is a linear reddish rash.
Lice. Of course there are 3 types of lice that infest and bite humans. Generally speaking, the only louse that may be commonly encountered in the West Coast are head lice. As indicated by their name, these lice occur on the head and cause itching. The nits or eggs of these pests are glued to the base of the head hairs. The (see below) eggs are similar in appearance to dandruff but remain attached to the hair. When touched dandruff moves and lice eggs do not.
Right Image. Head Louse. Image Courtesy Gilles San Martin CC BY SA 1.0
Chiggers. Chiggers also bite people and generally the biting stage (larval stage) is almost too small to be seen without magnification. Chiggers 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, beltline, 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, victims 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 or lower legs.
Right Image Courtesy Bugboy52.4 GNU Free Documentation
Household Products. There are literally hundreds of products that are capable of causing itching and irritations that are far more common that those resulting from arthropod bites. Some of the more common products associated with these symptoms are cosmetics, phosphate detergents, hair products, ammonia-based cleaning agents, soaps, medications, and printing inks. Certain types of clothing, particularly those containing fire retardants are common sources of itching and rashes.
Physical and Chemical Irritants. If 2 or more individuals experience the same irritation (especially in the absence of biting arthropods), the cause is typically environmental conditions or contaminants dispersed in the air. These fall into 2 broad categories.
Physical irritants: The most common physical irritants are tiny fragments of fabric, paper, dust, or insulation. When these fibers or similar items contact the skin, they can typically produce symptoms ranging from open sores, welts, intense itching accompanied by a rash, a “crawling sensation”, welts and open sores. In these cases, the irritation typically occurs over any exposed areas of the body such as legs, arms, head and neck. Irritations produced by paper fragments are especially common in offices where large quantities of paper are handled or processed daily. Continuous-feed paper multi-page forms and computers generate large quantities of these fragments.
Newly installed or badly worn synthetic drapes, carpets, or upholstery typically shed irritating fibers. Problem can developed from insulation fibers released into the air by cooling and heating systems in poor condition and insulation in drop-type ceiling tiles. These latter sources are especially suspected if there has been recent repair work on the ceiling.
Static electricity increases the attraction of tiny charged fibers to exposed skin resulting in itching. Electronic equipment, low relative humidity and nylon all increase levels of static electricity and the potential for problems from attracted fragments or fibers. Static electricity may also cause movement which individuals frequently believe is caused by critters crawling over the skin (delusory parasitosis).
Dry air alone can cause irritation which is frequently called “winter itch.” As skin loses moisture, itching can result. A similar feeling can result from large changes in temperature; however, in this case, it tends to make skin more sensitive. A skin moisturizer is often helpful in these situations.
Airborne chemical irritants: Indoor air pollution can be of considerable concern, especially in newer office buildings and other energy-efficient structures when air is recirculated over and over. This can also be a problem in homes. As the concentration of a given chemical in the air recirculates and consequently increases, individuals may experience headaches, dizziness, sore throat, and eye irritation. Air-borne contaminants can also produce skin irritations and rashes similar to those produced by insect bites. However, chemical contaminants are more often responsible for such reactions rather than biting insects. These chemicals include formaldehyde emitted via floor or wall coverings, ammonia-based cleaning agents, tobacco smoke, and solvents and resins in glues, paints, and adhesives. These reactions most often occur in buildings with poor ventilation, especially if they are new or have recently been refurbished with new wall or floor coverings
Itching and skin and irritation commonly occur with pregnancy (especially during the last trimester) and may also occur in conjunction with kidney, liver and thyroid disease, diabetes and shingles. Food allergies are another very common cause irritation and itching.
An increasing possible cause of skin irritation, rashes and sores in many areas of the United States is associated with the use of meth, the drug of choice in many areas of the U.S. 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 homeowner who thought she had bedbugs. 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 who suggested bedbugs 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. Considering the current notoriety that the American public has been experiencing in the past several years, there are a large number of individuals who 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 an 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 operator who is called in for inspection of a possible bedbug infestation will possibly be 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, millipedes, mold, rats, mice and even scabies mites. According to him, he became so paranoid about the whole situation that 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. Someone told him that the attic was full of housedust mites that were biting him and causing a severe rash. He went to an emergency center that routinely prescribes 5% permethrin cream for scabies mites. This material is quite effective and it typically takes one treatment for successfully eradication even though there is enough in one 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 months period-probably dangerous.
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 lucky that 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 any. 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. Lawyers (or more correctly insurance companies) frequently settle with this type of thing because it costs more to go to court than settle.
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 Bedbug Symptoms. Normally treatment for bedbug bites consists of application of a variety of creams to relieve the itching. Systemic corticosteroids are often prescribed for treating the itching and burning but often are not that effective for bedbug bites. Antihistamines can reduce itching in some cases, but have little if effect on the appearance and duration of the lesions.
Application of heat (hot water, hot water cloth, blow-dryer, hot washcloth) 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 mosquito and ticks reportedly are not 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.
Means of Home Infestations. There are a number ways how a business, home, hotel or similar structures can initially become infested with bedbugs. One of the most common is to pick them up while staying in a hotel, hostels, B and B or motel. Hotels or accommodations close to popular vacation locations are typically normally at high risk for bedbug’s infestations due to their continual influx of temporary residents and high rates of client turnover. Once acquired, the now hitchhiking bedbugs may then be transported and brought back to the homes of the guests in luggage, brief cases, jackets or any other items.
Purchases of used furniture or furniture rentals are rather common, especially in poor communities. Of course these undoubtedly help the rapid and repeated spread of bedbugs to new sites and redistribution of them back into places where these pests have been eliminated.
Large multi-unit buildings can be very difficult to rid of bedbugs, especially in low income areas. Bedbugs infest a new residence by traveling between multi-unit housing such as dorms, condos, and apartment buildings. This unintentional spread between adjacent home sites and nearby units is dependent to a great degree upon the level of infestation at the initial source. A heavy infestation is more likely to spread than a lower level infestation. Further potential to spread is also directly related to the manner in which infested items are disposed. For example, contaminated furniture should not be dragged through common areas while being removed.
Once bedbugs are well established in a structure, any control effort that does not include inspection of all units, combined with a coordinated program of treatment and occupant education is usually doomed to failure. These pests readily move from any partially treated site to adjacent rooms or floors, especially if repellent pesticides are used. They readily move along utility lines, through wall voids, heating ducts, elevator shafts, and mail or laundry chutes,
Bedbugs can also be brought into structures via acquisition of infested furniture including TVs, computers, microwave or any other small appliances and used clothing. One of the worst things a person can do is pick up a used item of furniture that has been discarded. It is not uncommon for someone to discard a perfectly good piece of furniture that has a bedbug infestation. Furniture does not necessarily have to have been previously owned or discarded. 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 an individual's stored or dirty clothes and hence be carried from area to area. It is also common for bedbugs to hide in clothing articles that are generally not frequently washed and for them to then spread when such items is are either stored publically with other apparel (as in locker rooms and on coat racks, public storage units). Typically bedbugs will not be 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 dozen individuals to tens of thousands. A single female bedbug brought into a home has a tremendous reproductive capacity, and population can built-up quite rapidly (geometrically) depending on prevailing temperatures and the availability of food (us). These pests reproduce prolifically and it is not at all unusual for applicators to encounter thousands of bedbugs in a single mattress. Sometimes the victims are not aware of the insects and do not notice or even react to the bites. Those bedbugs that are detected in a structure do not represent the entire infestation, as these insect are tremendously secretive 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. Reportedly 80% of an infestation is where the occupants sleep, unless the infestation is extremely heavy.
Steps to Minimize the Chances of Bringing Bedbugs into a Structure. The first step is to be aware of where is it more 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 near popular vacation sites. But the list continues to include barracks, apartments, buses, churches, cabins, cruise ships, community centers, dormitories, health clubs, dressing rooms, homes, jets, hospitals, Laundromats, motor homes, motels, moving vans, office building, nursing homes, resorts, schools, dorms, restaurants, subways, trains, theaters, and used furniture outlets. Bedbugs don’t necessarily prefer locations based on sanitation or individuals’ hygiene. The critical component for their survival is food, or put more simply our blood.
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 and don’t build nests.
Traveling greatly increases the chances of someone bringing bedbugs home. However, there are ways of minimizing the chances of bringing home these pests. Always make a thorough inspection prior to settling into any room. Be prepared and pack a flashlight (even the keychain LED model) to aid in your inspection. Most of the inspection should focus in and around the bed. Start with the headboard. This is usually held on the wall with brackets. Lift it up a few inches and lean the top away from the wall to access to the back. If traveling alone, request someone on staff to help. In hotel rooms, since the sheets are changed on a regular basis, the bedbugs may avoid the bed to a degree and congregate behind the headboard. 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 dressing table next to the bed and even pictures hanging on the wall next to the bed. If all these places are clear, enjoy the night. The next morning, look for blood spots and fecal spots on the sheets and mattress—bedbugs defecate soon after they feed.
If you find evidence, but no live bedbugs, the evidence may be old and doesn’t mean that the hotel is infested. Discretely tell the front desk what you found and request another room—preferably one that doesn’t share a wall with the room you just left. These pests are a nightmare for the hotel industry. Communication is key. Ideally hotels and motels readily discuss their bedbug programs and as a whole are receptive to request of their customers.
Don't unpack if you are going to stay a one night, or at least don’t unpack your clothing into drawers and leave your luggage on a luggage rack that is pulled away from the wall. Never leave luggage on or near the bed and keep it closed. This is especially true at night. In addition, avoid leaving clothing lying around the room at night.
Launder your clothes (hot soapy water and dryer) as quickly as possible once these items are brought back into the home. If you detected bedbugs subsequent to moving into a hotel room, you could request the hotel to pay for laundering and steam-cleaning your luggage; this may not happen. Regardless, once home you should unpack directly into plastic bags for taking clothes to the laundry. Suitcases should be carefully inspected and vacuumed or left outdoors sealed in plastic bags in the sun. This will quickly kill any bedbugs during hot days.
Bedbugs and Disease. These pests seem to have all of the needed requisites for transmitting diseases, but there are currently no known cases of these pests vectoring or transmitting any disease. They have been found naturally infected with at least 30 human pathogens but have never been documented to transmit any of these disease causing germs. There a few signs that they may be a vector for hepatitis B and in endemic areas of Chagas disease. As a result, from a disease transmission standpoint, bedbugs are considered less dangerous than some more common encountered insects such as mosquitoes, fleas and other biting flies. Education as to this fact should be maintained between building managers, occupants, governmental agencies and PMPs.
Inspecting for Bedbugs. Controlled Study-Dogs. The bedbug, Cimex lectularius, like other bedbug species is difficult to visually locate due to its cryptic nature. Bedbug detector dogs are useful for locating these pests because they use their sense of smell rather than sight. Reportedly, these dogs are trained to detect the presence of bedbugs (as few as one) and viable eggs by using a modified food and verbal reward system. Dogs are able to discriminate bedbugs from Camponotus floridanus-Florida carpenter ant, Blattella germanica-German cockroach and Reticulitermes flavipes-drywood termite with 97.5% accuracy. In addition, these dogs are capable of discriminating living bedbugs and viable bedbug eggs from dead bedbugs, bedbug feces and cast skins with 95% accuracy and a 3% false positive rate on bedbug feces. In a controlled study conducted in hotel rooms, dogs were 98% accurate in locating living bedbugs. If trained properly, dogs are now used effectively to locate live bedbugs and viable eggs.
Monitoring Devices. There are a number of bedbug monitoring devices on the market. Some are passive (meaning there are no attractants used to draw the bugs to the trap) while others are active utilizing heat or carbon dioxide to attract the pests. There appears to be little information as to the efficiency of the various available models. Two of the common forms are discussed below.
Bed bug Barrier Passive Glue Trap. The bed bug barriers are attached to the bottom of the bed legs creating an impassable barrier between the bed and the bedbugs. The Bed Bug Barrier uses natural, non-toxic resins and waxes to create an impassable permanent floor barrier that stops bedbugs before they can reach any sleeping victims. The natural glue in the barrier is non-drying, non-toxic and long lasting. The Bed Bug Barrier is designed to provide long-term protection and also serves as a monitoring tool. There are two basic designs. Depending on your bed post design, choose either the screw-in barrier (fits at top of bed legs with glue void facing downward) or the castor barrier (fits underneath bed leg with void facing upward).
The Climbup insect interceptor. As with others, it forms a barrier between the floor and bed. Bedbugs approaching a bed from the room will climb up the exterior surface and fall into the outer pit. Bedbugs climbing down from the bed will fall into the center pit
Cold. The use of cold for bedbug control is generally not very effective or cost effective as the use of heat. Bedbugs can withstand 5 degrees F. for short periods, and if acclimated can live at or below freezing. Use of cold for treatments of rooms for bedbugs is difficult and not often employed, but freezing various items within containers below 0 F (-19o C) for at least 4 days may be a practical alternative for limited infestations.
Steam. Steam treatments have been used effectively by some to quickly eliminate live bedbugs and their offspring from the seams of mattresses, cloth items and other situations. However, this technique requires training and care. Following instructions is essential with steam generating devices. These include operation of devices, safety and maintenance. The steam tip must typically be held about 1 1/2 inches from the surface being steamed. If held too far away, the steam may not be hot enough to kill the bedbugs and eggs. If too close, excess moisture may be injected into the material being treated which could lead to other problems such as facilitating increases of dust mite population and growth of surface molds. Reportedly the use of steam alone for bedbug control will not kill an entire infestation.
Physical Removal. Bedbugs can be vacuumed from any number of areas or resting sites, such as mattress seams, box springs and cracks and crevices, but bedbug eggs stick tightly to these surfaces and are typically hard to remove. With a highly efficient air (HEPA) filtered vacuum which will removes >99% of all particles greater than 0.3 micron diameter, many bedbug allergen and their debris can also be removed. Vacuuming, especially during the inspections process may remove a significant portion of the pest population and will usually kill some of the bugs. Bedbugs may also be removed from resting sites with the sticky tape, brushing them directly into a container and hand-picking. For those bedbugs that feed chiefly on birds and bats, it is critical to remove all host nesting materials. In addition, heat and/or a bedbug registered chemical can be used to treat the surrounding area.
Sticky Monitors. Sticky traps are an effective tool to monitor many crawling insects and are frequently used to augment other techniques for control of cockroaches and spiders. Although bedbugs will often be trapped on such monitors, some recent reports indicate that they are not very effective in detecting small to moderate populations of these pests.
Pesticide Applications-Residual Applications. Generally speaking, non-chemical products and techniques are incapable of efficiently eliminating heavy or well-established bedbug infestations. Proper placement of a registered and well-formulated residual insecticide is still considered by most the most practically and effective means of bedbug control. Effective control consists of applying interior sprays and dusts to surfaces that the bedbugs are found or will come in contact with. Dusts and microencapsulated formulations have a longer residual effect than others. Synergized pyrethrins are toxic to bedbugs and produce a flushing effect and are useful in detecting infestations of these pests. If the product label permits, addition of pyrethrins at 0.1-0.2% to other products labeled for bedbugs including microencapsulated products may increase efficacy of the mix by irritating the bugs, exciting them, and causing them to leave their hiding places. This may increase their potential exposure to the freshly deposited insecticide.
Silica gels, other dust formulations and diatomaceous earth can be of used for crack and crevice treatment. Retreatment should be done after the shortest interval permitted by the label until the bedbug population has been eliminated. The choice of chemical products and specific application techniques can depend on many factors. These may include the physical location and structural details of the bugs’ harborages, the product labels, the immediate environment, and local or national laws.
Crack-and-Crevice Applications. Due to the characteristic behavior of bedbugs hiding clustered together in cracks and narrow harborages, precisely applied crack-and-crevice applications are among the most effective techniques for control of these pests. There are a variety of formulations and a number of devices available for applying insecticides to bedbug infested areas. For example, dust formulations can be applied in electrical outlet boxes and in other places where it is desirable to employ low-risk, long-lasting insecticides and to minimize the possible effect of short circuiting electrical devices.
Fumigation. Fumigation of clothing, furniture, or other personal items can be extremely effective in killing all stages of bedbugs. However, such treatments will not prevent reinfestation as fumigants have a very short residual activity. Fumigation of an entire building would be equally effective but, again, would not prevent reinfestation, and rarely is practical and affordable.
Ultra Low Volume (ULV), Aerosols, and Foggers. Insecticides currently labeled for ULV, aerosols and foggers have little or no residual effects on bedbugs. Most will rarely reach cryptic bedbug hiding locations. If directly sprayed into these harborages, some of these products may stimulate a few bedbugs to leave their harborages and move out into the open. Bedbugs are seldom killed by repeated exposure to such products.
One main battle for survival bedbugs and other insects have is the loss of water or desiccation. A small flat insect such as a bedbug has a relatively large body surface area (where water can evaporate from) compared to their total volume for storing water. Their eggs and early instar nymphs are especially vulnerable to high heat due to their small sized and relatively large surface area. Since at least the early 1900s, bedbugs have been controlled by heating infested rooms or whole buildings to temperatures at least 115 F. In order for heat to be an effective tool for killing bedbugs, it is critical that high temperature and low relative humidity be attained for a minimum length of time (generally several hours). .
In the early 1900s, investigators demonstrated it was possible to destroy bedbugs in buildings ranging in size from a two-story house to a 350-room dormitory on a college campus. Steam boilers and furnaces were used to elevate the temperature in bedbug infested rooms to between 110˚F and 130˚F over a period ranging from several hours to a few days. The process is known as “superheating.” In the first edition of the “Handbook of Pest Control,” Arnold Mallis also mentioned using superheating to successfully de-bug an animal rearing laboratory. He reported that after eight hours of heating, “the mortality was so terrific that a carpet of bedbugs covered the floor, and a slight draft through the room piled up windrows of the bugs against several objects on the floor.” Due to the ease, Efforts to control bedbugs with heat diminished in the 1940s, due to the ease, economy and effectiveness of DDT. Interest was rekindled in the late-1980s.
This type of treatment has several pros and cons. Heat treatment provides no residual effect, and bedbugs can re-occupy any treated site immediately after temperatures return to suitable levels. There is the possibility of damages to structures and their contents. Of greatest concern is the possibility of fire. However, the latter is becoming of less concern with the development of a numbers of commercially available safe heat generators. It should be mentioned that initial cost of these heat generators can be quite costly but on the positive side the utilization of heat for bedbug control can be cost effective and if properly applied, can result in total control of these pests including their eggs. The latter is significant since few if any of the currently available pesticides will kill their eggs.
Heat can be an extremely valuable tool in removing (killing) all stages of this pest from clothing, sheets, blankets and other linen. Laundering infested items in hot water with detergent followed by at least 20 minutes in typical clothes dryer on low heat should kill all life stages of bedbugs. A number of pest control companies have now incorporated heat as part of their pest management scheme for controlling these pests. On a commercial basis, the use of heat is especially attractive for smaller structures or units such as college dorms, hotel rooms and individual apartment units.
Some customers do not want chemical treatment. Homeowners frequently have to spend hours cleaning out rooms prior to chemical treatment. Heat treatment offers a form of control where owners only need to remove the items that will be adversely affected by this process.
Reportedly, there is typically no follow up treatment needed for a heat remediation. Depending on the extent of the infestation, pesticide treatment may require several follow up treatments to ensure that all the hidden bugs and eggs have been destroyed. Another big selling point is the turn-around time. Heat remediation only requires that the premises be vacated during the treatment process and for a long enough time for the heat to disperse, generally 24 hours. For a hotel operator, this is a selling point. They can turn the room around in 24 hours and not lose nearly the amount of revenue as they would if they had to undergo a chemical treatment. The most important difference is the effectiveness of heat remediation. Heat remediation kills all the bugs and eggs in a room typically on first application. It is even effective through the walls into the surrounding wall voids of a room. Another plus is that heat remediation is Green. In addition, once the treatment is over, the heat dissipates.
Generally there are two types of heat remediation devices: propane powered and electrical powered. Propane powered equipment involves bulky ductwork, leaves residual fumes, and presents a potential fire hazard that can give pause to not only the customer, but also PCO’s. Electrical devices have traditionally been overly large and cumbersome and requiring more than several people to assist in set-up and operation. Many require their own generator to operate. This is an obvious turn off for any PCO who values his time and money. However, there currently are rugged and robust convection heater designed in a compact form which can be set-up and operated by one man.
One of the keys to operating these devices is the ability to slowly warm up a treated room. If a room is heated too rapidly, some of the bedbug may escape or be driven from the room. It follows that any heating system should have the ability to monitor the rate of heating up of a location.