The family Cimicidae includes bedbugs, of which two common species feed onhumans. Cimex lectularius is widely distributed in tropical andnon-tropical countries while C. hemipterus, commonly called thetropical bedbug, is essentially a species of the Old and New World tropicsalthough it can also occur in warm areas of some non-tropical countries, such asin Florida, USA. It is not easy to separate these two species, but in C.lectularius the prothorax is generally 2.5 times as wide as long,whereas in C. hemipterus it is only about twice as wide aslong. Also, the abdomen is more rounded in C.lectularius than in C. hemipterus.

A third species, Leptocimex boueti, is found mainly in WestAfrica but has also been recorded in South America. This species bites bats andalso people, but is much less important as a pest than theCimex species.

Infestations of bedbugs have increased since the 1990s in many countries,possibly due to increased global travel. For instance, after the 2000 OlympicGames nearly every hotel in Sydney was infested with bedbugs. Other factorsinclude insecticide resistance and warmer houses. Bedbugs are not consideredimportant vectors, but in addition to constituting a biting nuisance they havebeen reported as causing iron deficiency in infants.