The Bedbugs Never Left

Lawrence Charles Parish, MD, Editor in Chief; Joseph A. Witkowski, MD

In This Article

Introduction and Entomology

Night night, sleep tight
Don't let the bedbugs bite.
If they do...
Take a shoe and slap them
Till they're black and blue.

Bedbug bites are back, and perhaps they never left.[1] A recent issue of Meeting News calls attention to bedbug infestations in hotels in at least 27 states.[2]Traditionally, infestations of Cimex lenticularis were limited to hotels earning notably fewer than five stars. At one time, clean, upstanding citizens might have contracted clusters of the three red papules on the legs when traveling overnight in a Pullman car, but DDT nearly eliminated that problem. DDT has been banned, and sleeping cars barely exist. Why are bedbugs a problem today?

The bedbug is a member of the Hemipteran order of the family Cimicidae, is considered wingless, belongs to the genus Cimex, and is related to the more widespread bat bug. A cousin to the traditional bedbug is C. hemipterus or the tropical bedbug. Together, these bedbugs cover the world, creating intense itching wherever they bite.

C. lenticularis is 4-7 mm long as an adult, yellowish to brownish in color, oval, and flat. After feeding it is longer, plumper, and reddish brown (Figure 1). The bug's mouth has a three-segment proboscis that is used for piercing and sucking blood (Figure 1). The bug also has ventral stink glands that produce a pungent smell.

An engorged bedbug seen after feeding. Photo courtesy of the Department of Entomology, Soils, & Plant Science, Clemson University, Clemson, SC.

Whereas nymphs are nearly colorless, C. lenticularis eggs are white and approximately 1 mm in length. Females cement their eggs to anything at hand and produce between six and 10 eggs per week -- up to several hundred eggs in a lifetime. Females tend to cluster together, so the aggregate eggs counted at any one time may approach 500.[3] Males determine whether a female has recently copulated by "taste."[4]

The life cycle of C. lenticularis ranges from 4 to 6 weeks. In conditions of temperatures higher than 10°C and good humidity, eggs hatch in 6 days, after which there are five nymphal stages. Blood meals are requisite for progressing to the next stage[5](Figure 1). Bedbugs live for about 10 months and can go weeks without a blood meal. In laboratory conditions, bedbugs have been found to live for up to 4 years and without food for 550 days.[3]