Effects of fenoxycarb, a juvenile hormone mimic on testis of Poekilocerus pictus (F.)

Fenoxycarb is an insect growth regulator and as a juvenile hormone analogue, it interacts with the natural hormones involved in insect development inhibiting metamorphosis. Fenoxycarb (200μg/5μl acetone) was applied topically on two days old adult male Poekilocerus pictus (F.) and the insects were dissected after 4, 8, 12, 16, 20, 24 days of single dose treatment. During 4 to 24 days of treatment the following deformations were noticed. The basement membrane was distorted, the spermatogonia were pycnotic and degeneration of the primary as well as secondary spermatocytes and dissociation of spermatozoa were seen. The spermatozoa were dissociated from their bundles. During later stages cyst cells were no longer visible, the cytoplasm was weak and clumping of chromatin threads of primary spermatocytes and dissociated sperm heads were observed. The spermatogonia were enlarged and a few of these enlarged spermatogonia were binucleate, some of the secondary spermatocytes were showing division with visible metaphase stage, hypertrophied spermatids and dissociated spermatozoa were observed. As the time period increased, damage to nuclear and cytoplasmic material subsequently increased.