A decade or two ago, bedbugs had all but disappeared as a major American pest. Then they began to return, and within the last few years their presence in American homes has burgeoned into a modern pest epidemic. What are bedbugs, what are their life habits, and why have they returned, that is the subject of this article.
Bedbugs are classified as part of the insect family Cimicidae. Three bedbug species feed on people. The most important bedbug species in human infestations is Cimex lectularius. Bedbugs may infest any type of warm-blooded mammal, such as bats, birds, and mice.
Cimex lectularius is most usually found in the northern temperate weather of North America . Europe, and Central Asia and is most easily adapted to city dwelling areas. It dwells less often in southern temperate regions. In Florida and tropical areas it is replaced by C. hemipterus. At one time, thanks to effective insecticides such as DDT, bedbug infestations were greatly diminished in number. In recent years, however, because of the ban on the most powerful insecticides, greater urban congestion and the increase in international travel, bedbugs have made a comeback.
IDENTIFICATION AND LIFE CYCLE
Adult bedbugs are wingless 1/5 inch long oval rusty red or mahogany in color. Bedbug bodies are very thin and they have long antennae. Bedbug eyes are tiny, and the area behind their head expands forward on either side giving the appearance of a renaissance ruff collar. The immature bedbug appear identical to the adults except for their size, thinner cuticle, and a lighter, yellowish white color. Bedbugs are readily distinguished from kissing bugs, the vector of Chagas disease by their smaller size, more rounded shape, and lack of wings as adults.
Bedbugs are known for spread rapidly because even a single pregnant female can infest a home. This is because the female bedbug lays anywhere from 200 to 500 eggs (in batches of 10 to 50). They lay their eggs in very commonly available places, including rough surfaces such as wood or paper. Bedbug eggs are covered with a sticky substance and hatch in about 10 days. Even after the egg hatches, the shells frequently remain on the substrate. Subsequently, bedbugs pass through five nymphal stages of growth. Bedbug nymphs require a single blood meal before molting to the next stage. The entire bedbug life cycle from egg to adult stretches over a span of time lasting anywhere from 5 weeks to 4 months, depending on temperature. Bedbugs develop more rapidly in a warm climate with thermometry readings between 72 to 80 degrees. Both bedbug nymphs and adults usually feed on mammals at night and hide in dark places during the day. Common bedbug hiding places include mattresses and box spring seams, cracks in bed frames, behind loose wallpaper, on the back of picture frames, and inside sofa and chair fabric covering.
Bedbugs can live for 80 to 140 days without any external nutrition; bedbugs at later stages of development can survive longer without nutrition than younger bedbugs. Adult bedbugs have survived without food for as long as 550 days. An adult bedbug can ingest six times its bodily weight in blood, and a bed bug blood snack can extend 3 to 10 minutes. Mature bedbugs live about 10 months and because of the average age when bedbugs start breeding there can be up to 3 to 4 generations of bedbugs during the course of a year.
Bed bugs may be picked up in theaters, buses, trains, and other public places, and subsequently brought into the home on clothing, bedding, luggage, or even firewood. Additionally, although much less commonly, bed bugs that feed on other mammals and birds, (chickens, mice, rats, and rabbits), that live near the home may under some circumstances feed on humans if, for example, their primary hosts disappear.