Fenoxycarb (jha) improve the growth and cocoon quality of tasar silkworm, Antheraea mylitta drury

Topical application of Juvenile hormone analogue, Fenoxycarb on 5th Instar larvae and its Impact on growth and silk productivity In tropical tasar silkworm, Antherses mylitfs Drury was studied. Fenoxycarb @ 1, 2, 5, 10 and 20 μg/larva applied topically at 0 day old 5th instar larvae revealed that topical application of 10 μg/larva was effective and further development and quality improvement. Other doses applied either led to malformation of pupae or prolongation of larval duration. During 1 st crop, Fenoxycarb @ 1 0 μg/larva applied topically at 0 to 8 day old 5th instar larvae. Result indicated that 5 day old treated larvae Improved fresh larval weight 38.33 ±0.53 g (34.74%), cocoon weight 13.18 ±0.13 g (25.070%) and shell weight 1.46 ±0.02 g (38.800%) against control. Larval duration was not significantly differing in 5 day old treated larvae than control. During 2nd crop, same dose was applied topically at 0 to 12 days old 5th instar larvae and results revealed that 7 day old treated larvae improved larval weight 32.75 ±0.80 g (27.57%), cocoon weight 14.36 ± 0.33 g (16.670%) and shell weight 2.21 ± 0.11 g (25.70%) against control without prolongation of 5th Instar larval duration. Hence, it can be inferred that judicious use of Fenoxycarb (JHA) at particular age of 5th instar larvae of tropical tasar silkworm, A. mylitts may be helpful in enhancing silk productivity.