Bed Bug

The common bed bug, *Cimex lectularius*, belongs to the family Cimicidae within the order Hemiptera. Adults are approximately 4-5 mm in length, ovate, and dorsoventrally flattened, changing from a dark reddish-brown to a more distended, purplish hue after a blood meal. Its lifecycle comprises six stages: egg, five nymphal instars, and adult, with each nymphal instar requiring a full blood meal to molt. Under optimal conditions (25-30°C and 70-80% RH), eggs hatch in 6-10 days, nymphs complete development in 14-30 days, and adults can live for 6-12 months, producing 1-5 eggs per day after feeding. These insects are notably resilient, capable of surviving for several months without a blood meal, especially at lower temperatures.

Bed bugs are primarily nocturnal, displaying peak activity in the hours before dawn, coinciding with periods of deep human sleep, although opportunistic feeding can occur at any time if hosts are sedentary. They locate hosts primarily through thermoreception (body heat) and chemoreception, detecting exhaled carbon dioxide and other host kairomones like lactic acid. While not social in a true sense, bed bugs exhibit aggregative behaviors, mediated by arrestment pheromones contained within their fecal matter, leading to the formation of 'harborages.' Their feeding involves a salivary anesthetic and anticoagulant, resulting in painless bites that often manifest as clustered lesions or linear arrangements, commonly referred to as 'breakfast, lunch, and dinner.' Bites themselves rarely transmit pathogens, but reactions to saliva can cause significant dermatitis and secondary infections from scratching.