Bedbug.= بق الفراش |
bedbugs Cimicidae or bedbugs, are small parasitic insects. The most common type is Cimex lectularius.[2] 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.[3][4]
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 have increased in prevalence since about 1995.[5] Because infestation of human habitats has been on the increase, bedbug bites and related conditions have been on the rise as well.[6][7] 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.[7][8] Bedbugs have been known human parasites for thousands of years.[6] 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.[10] 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).[11] 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.[12] 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).[11] 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.[13] .
Bedbugs are obligatory hematophagous (bloodsucking) insects. Most species feed on humans only when other prey are unavailable.[14][15][16] Bedbugs are attracted to their hosts primarily by carbon dioxide, secondarily by warmth, and also by certain chemicals.[17] A bedbug pierces the skin of its host with two hollow feeding tubes shaped like tounges. 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.[4]It takes between five to ten minutes for a bedbug to become completely engorged with blood.”[18]
Although bedbugs can live for a year without feeding,[19] 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.[20] At the 57th Annual Meeting of the Entomological Society of America in 2009, it was reported that newer generations of pesticide-resistant bedbugs in Virginia could survive only two months without feeding.[21] DNA from human blood meals from bed bugs can be recovered for up to 90 days, which may allow bed bugs to be used for forensic purposes for identifying who the bed bugs have been feeding on.[22][23] |