Cockroaches are insects belonging to the order Blattodea (Blattaria). About 30 cockroach species out of 4,600 are associated with human habitats. Some species are well-known pests.
A Turkestan cockroach (Shelfordella lateralis) next to an approximately 108-million-year-old fossil cockroach from the Cretaceous Period.
A 40- to 50-million-year-old cockroach in Baltic amber (Eocene)
Domino cockroach Therea petiveriana, normally found in India
Head of Periplaneta americana
Insect wings are adult outgrowths of the insect exoskeleton that enable insects to fly. They are found on the second and third thoracic segments, and the two pairs are often referred to as the forewings and hindwings, respectively, though a few insects lack hindwings, even rudiments. The wings are strengthened by a number of longitudinal veins, which often have cross-connections that form closed "cells" in the membrane. The patterns resulting from the fusion and cross-connection of the wing veins are often diagnostic for different evolutionary lineages and can be used for identification to the family or even genus level in many orders of insects.
Original veins and wing posture of a dragonfly
Hoverflies hovering to mate
A cockchafer's hardened forewings raised, hindwings unfolding
Outstretched wing of a bumblebee