Development and silk production by silkworm larvae after topical application of methoprene

Juvenile hormone analogues have been tested as insect growth regulators in silkworm (Bombyx mori), seeking an increment of silk production. These chemical products, when applied in small or moderate rates, promote the extension of the last larval instar. To understand the physiologic consequences on silk production by the silkworm strain C115 x N108, the application of methoprene, a juvenile hormone analogue, was performed to evaluate its effects on larval development and silk production. Methoprene was topically applied 48h after the fourth larval ecdysis, on the dorsal integument of the 2nd thoracic segment of the insects, at seven rates between 0 and 20 ng a.i. Methoprene influenced positively the duration of the fifth instar and the weight gain of the insects. The application of 1ng methoprene resulted in the heaviest silkglands, cocoons, shell cocoons and pupae weights. Comparatively to the control, the increment on silk production (approximately 24%) by the use of 1ng methoprene was more accentuated than the corresponding negative effects on the cocooning rate (approximately 12%).

Saved in:
Bibliographic Details
Main Authors: Miranda,José Ednilson, Bortoli,Sérgio Antonio de, Takahashi,Roque
Format: Digital revista
Language:English
Published: Escola Superior de Agricultura "Luiz de Queiroz" 2002
Online Access:http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162002000300026
Tags: Add Tag
No Tags, Be the first to tag this record!