JUVENILE HORMONE AND SYNTHETIC ANALOGUES: EFFECTS ON LARVAL MOULT OF SILKWORM, BOMBYX MORI

Abstract

Morphogenetic activities of three synthetic compounds, dl-C₁₈-Cecropia juvenile hormone and its two analogues, on larval-larval moult of Bombyx silkworms were evaluated. Allatectomized 4th instar larvae moulted into 5th instar after injection or topical application of a certain amount of each compound. dl-C₁₈-Cecropia juvenile hormone was most active ; the dosage required for 50% larval moult induction was only 0.12μg per insect by topical application. No defect was seen in the adults developed from 5th instar larvae induced by the treatment with these compounds. The results mean that a single treatment with each compound satisfactorily substituted the juvenile hormone secreting organ, corpus allatum.