Bed bug infestation Bedbug bites Diagnosis of an infestation involves both finding bed bugs and the occurrence of compatible symptoms. However, arboviruses may be transmissible. The front wings are vestigial and reduced to pad-like structures. Bed bugs have segmented abdomens with microscopic hairs that give them a banded appearance.
Newly hatched nymphs are translucent, lighter in color, and become browner as they moult and reach maturity. A bed bug nymph of any age that has just consumed a blood meal has a bright red, translucent abdomen, fading to brown over the next several hours, and to opaque black within two days as the insect digests its meal.
Bed bugs may be mistaken for other insects, such as booklice , small cockroaches, or carpet beetles ; however, when warm and active, their movements are more ant-like and, like most other true bugs , they emit a characteristic disagreeable odor when crushed.
Bed bugs use pheromones and kairomones to communicate regarding nesting locations, feeding, and reproduction. The lifespan of bed bugs varies by species and is also dependent on feeding. Bed bugs can survive a wide range of temperatures and atmospheric compositions. Most species feed on humans only when other prey are unavailable. Bedbugs have mouth parts that saw through the skin, and inject saliva with anticoagulants and painkillers.
The bite usually produces a swelling with no red spot, but when many bugs feed on a small area, reddish spots may appear after the swelling subsides.
At the 57th annual meeting of the Entomological Society of America in , newer generations of pesticide-resistant bed bugs in Virginia were reported to survive only two months without feeding. The rostrum is composed of the maxillae and mandibles , which have been modified into elongated shapes from a basic, ancestral style.
The right and left maxillary stylets are connected at their midline and a section at the centerline forms a large food canal and a smaller salivary canal.
The entire maxillary and mandibular bundle penetrates the skin. The right and left mandibular stylets extend along the outer sides of their respective maxillary stylets and do not reach anywhere near the tip of the fused maxillary stylets.
The stylets are retained in a groove in the labium , and during feeding, they are freed from the groove as the jointed labium is bent or folded out of the way; its tip never enters the wound. Pressure from the blood vessel itself fills the insect with blood in three to five minutes.
The bug then withdraws the stylet bundle from the feeding position and retracts it back into the labial groove, folds the entire unit back under the head, and returns to its hiding place. Reproduction[ edit ] Male bed bug traumatically inseminating a female North Carolina State University found that bedbugs in contrast to most other insects tolerate incest and are able to genetically withstand the effects of inbreeding quite well.
In all bed bug 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. It is released when a bed bug is disturbed, as during an attack by a predator. A study demonstrated the alarm pheromone is also released by male bed bugs to repel other males that attempt to mate with them.
These microbes damage sperm cells, leaving them unable to fertilize female gametes. Due to these dangerous microbes, males have evolved antimicrobial ejaculate substances that prevent sperm damage. When the microbes contact sperm or the male genitals, the bed bug releases antimicrobial substances. Many species of these microbes live in the bodies of females after mating. The microbes can cause infections in the females. It has been suggested that females receive benefit from the ejaculate. Though the benefit is not direct, females are able to produce more eggs than optimum increasing the amount of the females' genes in the gene pool.
Due to these findings, Reinhard et. After measuring ejaculate volume, mating rate and estimating sperm density, Reinhardt et al. Despite these advances, the cost difference between ejaculate-dose dependence and mating frequency dependence have not been explored. These two names are not descriptive, so other terminologies are used.
On fertilization, the female's ovaries finish developing, which suggests that sperm plays a role other than fertilizing the egg. Fertilization also allows for egg production through the corpus allatum. Sperm remains viable in a female's spermathecae a better term is conceptacle , a sperm-carrying sack, for a long period of time as long as body temperature is optimum.
The female lays fertilized eggs until she depletes the sperm found in her conceptacle. After the depletion of sperm, she lays a few sterile eggs. The number of eggs a C. Traumatic insemination is the only way for copulation to occur in bed bugs. Females have evolved the spermalege to protect themselves from wounding and infection.
Because males lack this organ, traumatic insemination could leave them badly injured. For this reason, males have evolved alarm pheromones to signal their sex to other males. If a male C. Females are capable of producing alarm pheromones to avoid multiple mating, but they generally do not do so.
Two reasons are proposed as to why females do not release alarm pheromones to protect themselves. First, alarm pheromone production is costly. Due to egg production, females may refrain from spending additional energy on alarm pheromones. The second proposed reason is that releasing the alarm pheromone reduces the benefits associated with multiple mating. Bed bugs must molt six times before becoming fertile adults, and must consume at least one blood meal to complete each molt.
Fertilized females with enough food lay three to four eggs each day continually until the end of their lifespans about nine months under warm conditions , possibly generating as many as eggs in this time.
The abdomens of the sexes differ in that the males appear to have "pointed" abdomens, which are actually their copulatory organs, while females have more rounded abdomens. Since males are attracted to large body size, any bed bug with a recent blood meal can be seen as a potential mate. However, males will mount unfed, flat females on occasion.
The female is able to curl her abdomen forward and underneath toward the head to not mate. Males are generally unable to discriminate between the sexes until after mounting, but before inseminating.
When a bed bug is starved, it leaves its shelter and searches for a host. If it successfully feeds, it returns to its shelter. If it does not feed, it continues to search for a host. After searching—regardless of whether or not it has eaten—the bed bug returns to the shelter to aggregate before the photophase period of light during a day-night cycle.
Reis argues that two reasons explain why C. One is to find a mate and the other is to find shelter to avoid getting smashed after eating. Bed bugs may choose to aggregate because of predation, resistance to desiccation, and more opportunities to find a mate. Airborne pheromones are responsible for aggregations. Another source of aggregation could be the recognition of other C. Aggregations are formed and disbanded based on the associated cost and benefits.
Females are more often found separate from the aggregation than males. Females are more likely to expand the population range and find new sites. Active female dispersal can account for treatment failures. Males, when found in areas with few females, abandon an aggregation to find a new mate. The males excrete an aggregation pheromone into the air that attracts virgin females and arrests other males. Though strictly parasitic, they spend only a tiny fraction of their lifecycles physically attached to hosts.
Once a bed bug finishes feeding, it relocates to a place close to a known host, commonly in or near beds or couches in clusters of adults, juveniles, and eggs—which entomologists call harborage areas or simply harborages to which the insect returns after future feedings by following chemical trails. These places can vary greatly in format, including luggage, inside of vehicles, within furniture, amongst bedside clutter—even inside electrical sockets and nearby laptop computers.
Bed bugs may also nest near animals that have nested within a dwelling, such as bats, birds,  or rodents. They are also capable of surviving on domestic cats and dogs, though humans are the preferred host of C.
Bed bug control techniques Bed bugs are extremely difficult to get rid of. Bed bugs and their eggs will die on contact when exposed to surface temperatures above degrees and a steamer can reach well above degrees. However, biological pest control is not considered practical for eliminating bed bugs from human dwellings. Epidemiology of bed bugs Bed bugs occur around the world.
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. Antenna of the male — C. Haustellum, or sucker, closed — E. Side view of sucker — F.
Under part of head — G. Under lip — GG. Hair of the tube, and outside cases — H. Larva emerging from the eggs C. Pliny's Natural History , first published circa AD 77 in Rome, claimed bed bugs had medicinal value in treating ailments such as snake bites and ear infections. Belief in the medicinal use of bed bugs persisted until at least the 18th century, when Guettard recommended their use in the treatment of hysteria.
Some in the 18th century believed bed bugs had been brought to London with supplies of wood to rebuild the city after the Great Fire of London Giovanni Antonio Scopoli noted their presence in Carniola roughly equivalent to present-day Slovenia in the 18th century.
While diatomaceous earth performed poorly, silica gel may be effective. 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.