Bed bugs are parasitic insects in the genus Cimex that feed exclusively on blood. Cimex lectularius, the common bed bug, is the best known as it prefers to feed on human blood; other Cimex species specialize in other animals, e.g., bat bugs, such as Cimex pipistrelli (Europe), Cimex pilosellus (Western United States), and Cimex adjunctus (entire Eastern United States)
The name bed bug derives from the preferred habitat of Cimex lectularius: warm houses and especially near or inside beds or other sleep areas. Bed bugs are mainly active at night but are not exclusively nocturnal. They usually feed on their hosts without being noticed.
A number of adverse health effects may result from bed bug bites, including skin rashes, psychological effects, and allergic symptoms. Bed bugs are not known to transmit any pathogens as disease vectors. Certain signs and symptoms suggest the presence of bed bugs; finding the adult insects confirms the diagnosis.
Bed bugs have been known as human parasites for thousands of years. At a point in the early 1940s, they were mostly eradicated in the developed world, but have increased in prevalence since 1995, likely due to pesticide resistance, governmental bans on effective pesticides, and international travel. Because infestation of human habitats has begun to increase, bed bug bites and related conditions have also been on the rise.
Physical Description of bed bugs
Adult bed bugs are light brown to reddish-brown, flat, oval, and have no hind wings. 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. Adults grow to 4–5 mm (0.16–0.20 in) long and 1.5–3 mm (0.059–0.118 in) wide.
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 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; they can survive for at least five days at −10 °C (14 °F), but die after 15 minutes of exposure to −32 °C (−26 °F). Common commercial and residential freezers reach temperatures low enough to kill most life stages of bed bugs, with 95% mortality after 3 days at −12 °C (10 °F). They show high desiccation tolerance, surviving low humidity and a 35–40 °C range even with the 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 45 °C (113 °F); all stages of life are killed by 7 minutes of exposure to 46 °C (115 °F).Bed bugs 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.