Ovary and testis development in different stages and in the caste of Kalotermes flavicollis (Fabr.) (Isoptera Kalotermitidae)

The structure of gonads during normal development and in the sterile caste of Kalotennes flavicollis (Fabr.) was studied using light and electron micro- scope. The typical organization of the ovary is acquired between the 2nd and 3rd larval stage, and by the testis between the 4th and the 5th stages. Ovary development gradually advanced to the 5th larval stage; in 1st and 2nd stage nymphs, presoldiers, soldiers and pseudergates, oogenesis is blocked at the beginning of previtellogenesis with terminal oocyte degeneration. After the imaginal moult, terminal oocytes begin to store yolk. Spermatogenesis up to mature spermatozoa is already completed at the 5th larval stage. Mature spermatozoa are also observed in the testes of 1st and 2nd stage nymphs, presoldiers, soldiers and pseudergates. The testis reaches a maximum size and is fully functional in reproductives through an extensive recruitment of secondary spermatogonia.