THE EFFECTS OF AZADIRACHTIN-A ON THE MORPHOLOGY OF THE RING COMPLEX OF LUCILIA-CUPRINA (WIED) LARVAE (DIPTERA, INSECTA)

This study investigated the effect of azadirachtin A (AZ A) on the ult rastructure of the endocrine glands (the prothoracic gland, the corpus allatum, and the corpus cardiacum) responsible for controlling moulti ng and ecdysis in Lucilia cuprina larvae. All constituent endocrine gl ands within the ring complex exhibited ultrastructural change after ex posure of larvae to AZ A in the diet. The effects on the nucleus were the most noticeable and included: (1) crenulation of nuclear shape, (2 ) clumping of heterochromatin, and (3) pyknosis. The degenerative chan ges to the nuclei appeared to precede changes within the cytoplasm. It was concluded that the degeneration of all three endocrine glands wit hin the ring complex would contribute to a generalised disruption of n euroendocrine function.