On the body outgrowths and the phenomenon of ‘sweating’ in the nymphal instars of Tingidae (Hemiptera: Heteroptera)

Summary

The nymphal instars of the summer species of Tingidae possess body outgrowths which are morphologically different from those of the winter forms. The peak population of the summer species coincides with the onset and progress of monsoon. Histological studies of the body outgrowths of the nymphal instars of these two forms reveal that the summer forms bear special sub-hypodermal globule-secreting cells that exhibit differential secretory activity during the stadial period. The secretion, in the form of fine globules that accumulate in the subcuticular space on the dorsal surface, is exuded as sticky globules through the globulated spines, giving the dorsal surface of these instars the appearance of ‘sweating’. These globule-secreting cells are here suggested to be osmoregulatory in function.