Petiole (insect anatomy) a pedicel, but in entomology, that term is more correctly reserved for the second segment of the antenna; while in arachnology, 'pedicel' is the accepted term to define the constriction between the cephalothorax and abdomen of spiders. The plump portion of the abdomen posterior to the petiole (and postpetiole in the Myrmicinae) is called the gaster. The structure of the petiole is an easy way to visually classify ants, because the major subfamilies of Formicidae have structural differences: some ants have two-segmented petioles, while others have a single-segmented petiole. Petiole may also be used in the context of wing veins,
Insect wing Insect wing Insect wings are adult outgrowths of the insect exoskeleton that enable insects to fly. They are found on the second and third thoracic segments (the mesothorax and metathorax), 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 (extreme examples include the dragonflies and lacewings). The patterns resulting from the fusion and cross-connection of the wing veins are often diagnostic for different evolutionary lineages and