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 thermoregulation Insect thermoregulation Insect thermoregulation is the process whereby insects maintain body temperatures within certain boundaries. Insects have traditionally been considered as "poikilotherms" (animals in which body temperature is variable and dependent on ambient temperature) as opposed to being "homeothermic" (animals which maintain a stable internal body temperature regardless of external influences). However, the term "temperature regulation", or "thermoregulation", is currently used to describe the ability of insects and other animals to maintain a stable temperature (either above or below ambient temperature), at least in a portion of their bodies by physiological or behavioral means. While many insects are "ectotherms" (animals