Everything You Always (or Never) Wanted to Know About Bed Bugs

Recently, I received an email from a reader who was concerned about bed bugs. I had done research over a year ago but decided that it might be a good idea to get the latest information on the topic. I received most of my information from Wikipedia. One thing that I learned was that our vaccuum cleaners might be one of the best ways to rid bed bugs from homes, motels, etc. You might find the midsection of this report to be just a bit on the boring side. Stick with it though, Folks, There is additional information after that that you may find to be very interesting. Bottom line is that bed bugs are making a major leap back into the lives of the American people...Ugghh!!! VLE-B

Cimicidae or bedbugs, are small parasitic insects. The most common type is Cimex lectularius. The term usually refers to species that prefer to feed on human blood. All insects in this family live by feeding exclusively on the blood of warm-blooded animals.

A number of health effects may occur due to bed bugs including skin rashes, psychological effects and allergic symptoms. Diagnosis involves both finding bed bugs and the occurrence of compatible symptoms. Treatment is otherwise symptomatic.

In the developed world, bedbugs were largely eradicated as pests in the early 1940s, however they have increased in prevalence since about 1995. Because infestation of human habitats has been on the increase, bedbug bites and related conditions have been on the rise as well. The exact causes of this resurgence remain unclear; it is variously ascribed to greater foreign travel, more frequent exchange of second-hand furnishings among homes, a greater focus on control of other pests resulting in neglect of bedbug countermeasures, and increasing resistance to pesticides. Bedbugs have been known human parasites for thousands of years.

The name "bedbug" is derived from the insect's preferred habitat of houses and especially beds or other areas where people sleep. Bedbugs, though not strictly nocturnal, are mainly active at night and are capable of feeding unnoticed on their hosts. They have however been known by a variety of names including wall louse, mahogany flat, crimson rambler, heavy dragoon, chinche and redcoat.

Adult bedbugs are reddish-brown, flattened, oval and wingless. Bedbugs have microscopic hairs that give them a banded appearance. Adults grow to 4–5 mm in length and 1.5–3 mm wide. Newly hatched nymphs are translucent, lighter in color and become browner as they moult and reach maturity. Bedbugs may be mistaken for other insects such as booklice and carpet beetles, or vice-versa.

Bedbugs use pheromones and kairomones to communicate regarding nesting locations, feeding and reproduction.

The life span of bedbugs varies by species and is also dependent on feeding.

Bedbugs can survive a wide range of temperatures and atmospheric compositions. Below 16.1 °C (61.0 °F), adults enter semi-hibernation and can survive longer. Bedbugs can survive for at least five days at −10 °C (14.0 °F) but will die after 15 minutes of exposure to −32 °C (−26 °F). They show high desiccation tolerance, surviving low humidity and a 35–40 °C range even with loss of one-third of body weight; earlier life stages are more susceptible to drying out than later ones. The thermal death point for C. lectularius is high: 45 °C (113 °F), and all stages of life are killed by 7 minutes of exposure to 46 °C (115 °F). Bedbugs apparently cannot survive high concentrations of carbon dioxide for very long; exposure to nearly-pure nitrogen atmospheres, however, appears to have relatively little effect even after 72 hours.


Scanning electron micrograph (SEM) of Cimex lectularius, digitally colorized with the insect’s skin-piercing mouthparts highlighted in purple and red. Bedbugs are obligatory hematophagous (bloodsucking) insects. Most species feed on humans only when other prey are unavailable. Bedbugs are attracted to their hosts primarily by carbon dioxide, secondarily by warmth, and also by certain chemicals.

A bedbug pierces the skin of its host with two hollow feeding tubes shaped like tongues. With one tube it injects its saliva, which contains anticoagulants and anesthetics, while with the other it withdraws the blood of its host. After feeding for about five minutes, the bug returns to its hiding place. It takes between five to ten minutes for a bedbug to become completely engorged with blood.”

Although bedbugs can live for a year without feeding, they normally try to feed every five to ten days. In cold weather, bedbugs can live for about a year; at temperatures more conducive to activity and feeding, about 5 months.

At the 57th Annual Meeting of the Entomological Society of America in 2009, newer generations of pesticide-resistant bedbugs in Virginia were reported to survive only two months without feeding.

DNA from human blood meals from bedbugs can be recovered for up to 90 days, which may allow them to be used for forensic purposes for identifying on whom the bedbugs have been feeding.

Reproduction
A bedbug (Cimex lectularius) traumatically inseminates another. All bedbugs mate by traumatic insemination. Female bedbugs possess a reproductive tract that functions during oviposition, but the male doesn't use this tract for sperm insemination. Instead, the male pierces the female's abdomen with his hypodermic genitalia and ejaculates into the body cavity. In all bedbug species except Primicimex cavernis, sperm are injected into the mesospermalege, a component of the spermalege, a secondary genital structure that reduces the wounding and immunological costs of traumatic insemination. Injected sperm travel via the haemolymph (blood) to sperm storage structures called seminal conceptacles, with fertilisation eventually taking place at the ovaries.

Male bedbugs sometimes attempt to mate with other males and pierce the latter in the abdomen. This behaviour occurs because sexual attraction in bedbugs is based primarily on size, and males will mount any freshly-fed partner regardless of sex. The "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.

C. lectularius and C. hemipterus will mate with each other given the opportunity, but the eggs then produced are usually sterile. In a 1988 study, 1 egg out of 479 was fertile and resulted in a hybrid, C. hemipterus × lectularius.

Life stages: Bedbugs have six life stages (five immature and an adult stage). They will shed their skins through a molting process (ecdysis) throughout multiple stages of their lives. The discarded outer shells look like clear, empty exoskeletons of the bugs themselves. Bedbugs must molt six times before becoming fertile adults.

Bedbug (4 mm length; 2.5 mm width), shown in a film roll plastic container, on the right is the recently sloughed skin from its nymph stage

Infestation
A number of health effects may occur due to bedbugs including skin rashes, psychological effects and allergic symptoms. Although bed bugs are able to be infected by at least 28 human pathogens, no study has ever found that the insect is able to transmit the pathogen to a human being. Bedbug bites or cimicosis may lead to a range of skin manifestations from no visible effects to prominent blisters. Diagnosis involves both finding bedbugs and the occurrence of compatible symptoms. Treatment involves the elimination of the insect but is otherwise symptomatic.

Dwellings can become infested with bedbugs in a variety of ways, from:

Bugs and eggs that "hitchhiked in" on pets, or on clothing and luggage
Infested items (such as furniture or clothing) brought in
Nearby dwellings or infested items, if there are easy routes (through duct work or false ceilings)
Wild animals (such as bats or birds)
People visiting from a source of infestation; bedbugs, like roaches, are transferred by clothing, luggage, or a person's body.

Detection
An engorged female bedbug (Cimex lectularius) with eggs, discovered in the screw hole of a wooden bed frameBedbugs are elusive and usually nocturnal, which can make them hard to spot. They often lodge unnoticed in dark crevices, and eggs can be nestled in fabric seams. Aside from bite symptoms, signs include fecal spots, blood smears on sheets, and molts.

Bedbugs can be found singly, but often congregate once established. They usually remain close to hosts, commonly in or near beds or couches. Nesting locations can vary greatly, however, including luggage, vehicles, furniture and bedside clutter. Bedbugs may also nest near animals that have nested within a dwelling, such as bats, birds, or rodents. The eggs of bedbugs are found in similar places where the bedbugs themselves are found, and are attached to surfaces by a sticky substance.

Attractant devices for detection use heat and/or carbon dioxide.

Bedbugs can be detected by their characteristic smell of almonds or over-ripe raspberries. Bedbug detection dogs are trained to pinpoint infestations, with a possible accuracy rate of 97.5%, based upon tests conducted under controlled conditions by researchers. The success rates in these tests may not reflect real world success rates of a pest companies’ dogs, operating with many more variables in the field. Dog detection can often occur in minutes where a pest control practitioner might need an hour. In the United States, about 100 dogs are used to find bedbugs as of mid-2009. A few companies are experimenting with high speed gas chromatography to detect bedbugs and other insect vermin.

ManagementEradication of bedbugs frequently requires a combination of pesticide and non-pesticide approaches. Pesticides that have historically been found to be effective include: pyrethroids, dichlorvos and malathion. Resistance to pesticides has increased significantly over time and there are concerns of negative health effects from their use. Mechanical approaches such as vacuuming up the insects and heat treating or wrapping mattresses have been recommended.

The carbamate insecticide propoxur is highly toxic to bedbugs, but the Environmental Protection Agency (EPA) has been reluctant to approve such an indoor use because of its potential toxicity to children after chronic exposure.

Pesticide resistanceBedbugs are developing resistance to various pesticides including DDT and organophosphates.

Some populations have developed a resistance to pyrethroid insecticides. Although now often ineffective, the resistance to pyrethroid allows for new chemicals that work in different ways to be investigated, so chemical management can continue to be one part in the resolving of bed bug infestations. There is growing interest in both synthetic pyrethroid and the pyrrole insecticide, chlorfenapyr. Insect growth regulators, such as hydroprene (Gentrol), are also sometimes used.

Populations in Arkansas have been found to be highly resistant to DDT, with an LD50 of more than 100,000 ppm. DDT was seen to make bedbugs more active in studies conducted in Africa.

Bedbug pesticide-resistance appears to be increasing dramatically. Bedbug populations sampled across the U.S. showed a tolerance for pyrethroids several thousands of times greater than laboratory bedbugs. New York City bedbugs have been found to be 264 times more resistant to deltamethrin than Florida bedbugs due to nerve cell mutations.

A population genetics study of bedbugs in the United States, Canada, and Australia using a mitochondrial DNA marker found high levels of genetic variation. This suggests the studied bedbug populations did not undergo a genetic bottleneck as one would expect from insecticide control during the 1940s and 1950s, but instead, that populations may have been maintained on other hosts such as birds and bats. In contrast to the high amount of genetic variation observed with the mitochondrial DNA marker, no genetic variation in a nuclear RNA marker was observed. This suggests increased gene flow of previously isolated bedbug populations, and given the absence of barriers to gene flow, the spread of insecticide resistance may be rapid.

PredatorsNatural enemies of bedbugs include the masked hunter (also known as "masked bedbug hunter"), cockroaches, ants, spiders (particularly Thanatus flavidus), mites and centipedes. The Pharaoh ant's (Monomorium pharaonis) venom is lethal to bedbugs. Biological pest control is not very practical for eliminating bedbugs from human dwellings.

Epidemiology of bedbugs
Bedbugs are found every where in the whole world . Rates of infestations in developed countries, while decreasing from the 1930s to the 1980s, have increased dramatically since the 1980s. Previously, they were common in the developing world, but rare in the developed world. The increase in the developed world may have been caused by increased international travel, resistance to insecticides, and the use of new pest-control methods that do not affect bedbugs. The fall in bedbug populations after the 1930s in the developed world is believed to be partly due to the use of DDT to kill cockroaches. The invention of the vacuum cleaner and simplification of furniture design may have also played a role. Others believe it might simply be the cyclical nature of the organism.

The common bedbug (Cimex lectularius) is the species best adapted to human environments. It is found in temperate climates throughout the world. Other species include Cimex hemipterus, found in tropical regions, which also infests poultry and bats, and Leptocimex boueti, found in the tropics of West Africa and South America, which infests bats and humans. Cimex pilosellus and Cimex pipistrella primarily infest bats, while Haematosiphon inodora, a species of North America, primarily infests poultry.

History

Bedbugs were mentioned in ancient Greece as early as 400 BC, and were later mentioned by Aristotle. Pliny's Natural History, first published circa 77 AD in Rome, claimed bedbugs had medicinal value in treating ailments such as snake bites and ear infections. (Belief in the medicinal use of bedbugs persisted until at least the 18th century, when Guettard recommended their use in the treatment of hysteria. Bedbugs were first mentioned in Germany in the 11th century, in France in the 13th century and in England in 1583, though they remained rare in England until 1670. Some in the 18th century believed bedbugs had been brought to London with supplies of wood to rebuild the city after the Great Fire of London (1666). Giovanni Antonio Scopoli noted their presence in Carniola (roughly equivalent to present-day Slovenia) in the 18th century.

Traditional methods of repelling and/or killing bedbugs include the use of plants, fungi, and insects (or their extracts), such as black pepper, black cohosh (Actaea racemosa), Pseudarthria hookeri, Laggera alata (Chinese yángmáo cǎo), Eucalyptus saligna oil, henna (Lawsonia inermis or camphire), "infused oil of Melolontha vulgaris" (presumably cockchafer), fly agaric (Amanita muscaria), Actaea spp. (e.g. black cohosh), tobacco, "heated oil of Terebinthina" (i.e. true turpentine), wild mint (Mentha arvensis), narrow-leaved pepperwort (Lepidium ruderale), Myrica spp. (e.g. bayberry), Robert geranium (Geranium robertianum), bugbane (Cimicifuga spp.), "herb and seeds of Cannabis", "opulus" berries (possibly maple or European cranberrybush), masked hunter bugs (Reduvius personatus), "and many others."

In the mid-19th century, smoke from peat fires was recommended.

Dusts have been used to ward off insects from grain storage for centuries, including "plant ash, lime, dolomite, certain types of soil, and diatomaceous earth or Kieselguhr". Of these, diatomaceous earth in particular has seen a revival as a nontoxic (when in amorphous form) residual pesticide for bedbug abatement. Insects exposed to diatomaceous earth may take several days to die.

Basket-work panels were put around beds and shaken out in the morning, in the UK and in France in the 19th century. Scattering leaves of plants with microscopic hooked hairs around a bed at night, then sweeping them up in the morning and burning them, was a technique reportedly used in southern Rhodesia and in the Balkans.

Prior to the mid-twentieth century, bedbugs were very common. According to a report by the UK Ministry of Health, in 1933 there were many areas where all the houses had some degree of bedbug infestation.

Bedbugs were a serious problem during World War II. General MacArthur commented that bedbugs are the "greatest nuisance insect problem ... at bases in the U.S.

With the arrival of potent pesticides, famously DDT in the 1940s, bedbugs almost disappeared in western countries. However, bedbug infestations have resurged in recent years, for reasons which are not clear, but contributing factors may be complacency, increased resistance and increased international travel. The current wave of bedbug infestations across America has spawned an industry for bedbug prevention, eradication and the reporting of infestations.

Hopefully, this information will help you to understand the bed bug a bit more.

VLE-B