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 high mechanical power output which in turn, due to biochemical inefficiencies, end up producing large amounts of heat. Thus, a flying insect produces heat which, as long as it does not exceed an upper lethal limit, will be tolerated. However, if the flying insect is also exposed to external sources of heat (for example, radiation from the sun) or ambient temperatures are too high, it should be able to thermoregulate and stay in its temperature comfort zone. The first mechanism that comes to mind for insects to lose heat during flight is convection because higher speeds necessarily increase convective cooling.