Oogenesis in immature stages and sterile castes of Kalotermes flavicollis (Fabr.) (Isoptera: Kalotermitidae

Ovaries of winged and dewinged imagos, 2nd instar nymphs, pseudergates, presoldiers and soldiers of Kalotermes flavicollis were investigated. During the normal developmental cycle, after the imaginal moult, the ovary starts to produce eggs as a result of the activation of oogenic processes. In pseudergates, presoldiers and soldiers oogenesis is blocked at the first previtellogenic stage and the oocytes undergo degeneration. In nymphs a block is also observed, but it happens at the second previtellogenic stage and without any hint of oocyte degeneration. The evidence suggests that in pseudergates, presoldiers and soldiers, the oogenesis block is related to a lack of differentiation of follicular cells which may be one of the main targets for control factors. .