Abstract
Effect of juvenile hormone analogue (methoprene) (isopropyl (2E, 4E)-11-methoxy-3, 7, 11-trimethyl-2, 4-dodecadinoate) at concentrations of 0.003, 0.005 and 0.01ppm on Dok-Bua, Thai hybrid strain of the silkworm, Bombyx mori L, topically applied on thoracic segment, at 48, 72 and 96 hour was studied. The results showed that the mature larvae treated at 96 hr did not spin cocoons and died in the mountage. In larvae treated at 48 and 72 hour, larval duration was prolonged for two days compared with controls. Cocoon weight and cocoon shell weight increased when larvae at 48 hour were treated with 0.01 ppm methoprene. The length and the weight of fiber from treated larvae at 48 and 72 hour increased from controls.
