Efeitos de três análogos do hormônio juvenil aplicados em bicho-da-seda, Bombyx mori L. (Lepidoptera: Bombycidae)
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Data
2002-03-01
Autores
MIRANDA, JOSÉ E. [UNESP]
BORTOLI, SÉRGIO A. DE [UNESP]
TAKAHASHI, ROQUE [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Entomológica do Brasil
Resumo
Análogos do hormônio juvenil (AHJ) têm sido testados como reguladores de crescimento de Bombyx mori L., com vistas ao incremento da produção de casulos. Esses produtos, quando aplicados em doses adequadas, prolongam o período larval. Os efeitos da aplicação de AHJ podem variar com o produto, a linhagem e o momento de aplicação. Este estudo teve por objetivo avaliar o efeito da aplicação tópica, em diferentes momentos, de três análogos do hormônio juvenil sobre o crescimento dos insetos e a produção de seda da linhagem brasileira C115xN108 do bicho-da-seda. Os produtos piriproxifem, metoprene e fenoxicarbe foram aplicados em larvas do bicho-da-seda a 24h, 48h, 72h e 96h após o início do quinto ínstar (HQI) e seus efeitos sobre características biológicas larvais e adultas e a produção de seda foram avaliados. Independentemente do momento de aplicação, os três produtos afetaram todos os parâmetros avaliados. A reserva de nutrientes acumulada durante o período larval prolongado dos insetos tratados foi destinada ao crescimento das glândulas sericígenas e, também, convertida em peso corporal, com conseqüentes incrementos na produção de seda. Aplicações entre 48 e 72 HQI provocaram os maiores incrementos na biomassa e na produção de casulos de B. mori. Variações no momento de aplicação de 24h e 96h não influenciaram a emergência ou a oviposição de adultos de B. mori, nem a viabilidade dos ovos.
Juvenile hormone analogues (JHA) have been tested as growth regulators of Bombyx mori L., aiming to increase the cocoon production. These chemicals, when applied in appropriate doses, promote prolongation of the larval period. The effects of JHA application may vary with the product, strain, and time of application. The objective of this study was to evaluate the topical application in different times of three JHA and their effects on larval growth and silk production of the Brazilian silkworm strain C115xN108. Pyriproxyfen, methoprene and fenoxycarb were applied on silkworm larvae at 24h, 48h, 72h or 96h after the beginning of the fifth instar (HFI) and the effects of the products on larval and adult biological characters and silk production were evaluated. Independently of the time of application, the three products affected all the evaluated parameters. The nutrients stored during the extended period by the treated insects were used for growing the silk glands and were converted in corporal weight, with consequent increments in the silk production. Applications of piryproxyfen, methoprene and fenoxycarb between 48 and 72 HFI promoted, in a general way, the largest increments in the biomass and cocoon production of B. mori. Variations in the time of application between 24 and 96 HFI did not influence adult emergence, oviposition or the egg viability of B. mori.
Juvenile hormone analogues (JHA) have been tested as growth regulators of Bombyx mori L., aiming to increase the cocoon production. These chemicals, when applied in appropriate doses, promote prolongation of the larval period. The effects of JHA application may vary with the product, strain, and time of application. The objective of this study was to evaluate the topical application in different times of three JHA and their effects on larval growth and silk production of the Brazilian silkworm strain C115xN108. Pyriproxyfen, methoprene and fenoxycarb were applied on silkworm larvae at 24h, 48h, 72h or 96h after the beginning of the fifth instar (HFI) and the effects of the products on larval and adult biological characters and silk production were evaluated. Independently of the time of application, the three products affected all the evaluated parameters. The nutrients stored during the extended period by the treated insects were used for growing the silk glands and were converted in corporal weight, with consequent increments in the silk production. Applications of piryproxyfen, methoprene and fenoxycarb between 48 and 72 HFI promoted, in a general way, the largest increments in the biomass and cocoon production of B. mori. Variations in the time of application between 24 and 96 HFI did not influence adult emergence, oviposition or the egg viability of B. mori.
Descrição
Palavras-chave
Fenoxicarbe, metoprene, piriproxifem, regulador de crescimento de insetos, produção de casulos, Fenoxycarb, methoprene, pyriproxyfen, Insect growth regulator, cocoon production
Como citar
Neotropical Entomology. Sociedade Entomológica do Brasil, v. 31, n. 1, p. 19-25, 2002.