Blattodea contains over 4500 species worldwide, with about 150 species in Europe. They are among the most ancient winged insects, the earliest fossils dating back to the Carboniferous. The group is well defined by a combination of characters: eggs usually contained in oothecae (egg cases), leathery forewings, male genitalia asymmetrical and cerci* with one or more segments. Most cockroaches are tropical and found in a wide variety of habitats such as dead or decaying leaves or trees, caves, under stones, in nests of social insects etc. Cockroaches are mostly scavengers eating organic material. Less than 1% (30 species) are associated with humans, but these species contribute to the unpopular reputation of these insects. Cockroaches exhibit diverse reproductive biology. Most species have sexual reproduction, but some populations of Pycnoscelus surinamensis are parthenogenetic. These hemimetabolous insects produce hardened oothecae deposited on a substrate or membraneous oothecae that are incubated in a brood sac within the female’s body. Some species exhibit a high level of parental care.
