Susceptibility of Different Instars of the Spruce Budworm (Lepidoptera: Tortricidae) to Bacillus thuringiensis var. kurstaki Estimated with a Droplet-Feeding Method

Effect of Insect Larval Midgut Proteases on the Activity of Bacillus thuringiensis Cry Toxins

“…These differences could possibly result, at least in part, from the fact that the brush border membrane vesicles (17,36) and midgut juice were isolated from fifth-instar larvae, the electrophysiological experiments were carried with midguts isolated from thirdinstar larvae, and in vivo toxicity data were obtained using neonate larvae. Numerous authors have reported differential effects of the larval instar on the potency of B. thuringiensis toxins (2,3,9,12,18,19,21,24,31,39,42). For example, Gilliland et al (12) observed that M. sexta third-instar larvae had significantly fewer binding sites for Cry1Ac than neonates while no significant changes were observed for Cry1Ca.…”

A brief review of the past use of baculoviruses for the management of eruptive forest defoliators and recent developments on a sawfly virus in Canada

“…Ingestion of baculovirus OBs from a baculovirus has been known to sometimes induce mortality in closely related species (e.g., Gröner 1986, Doyle et al 1990, Hostetter and Puttler 1991, Cory 2000. Indeed, laboratory bioassays using a dropletfeeding method (van Frankenhuyzen et al 1997) indicated that the ingestion of a dose of 1 ϫ 10 6 OBs of NeabNPV by third-instar larvae of the pine false webworm reduced survival to the ultimate larval stadium by 51% compared with larvae that had ingested water only . Therefore, a ground spray trial using a mistblower was conducted in a 1-ha red pine plantation located in Ontario in 2002.…”

<htm> <i> Bacillus thuringiensis</i> var. <i>kurstaki</i> (Bacillaceae): potencial no controle, no desenvolvimento e reprodução de <i>Oxydia vesulia </i>(Geometridae), em laboratório</htm>

“…(Lepidoptera: Tortricidae), ocorre o contrário. VAN-FRANKENHUYZEN et al (1997) VAN-FRANKENHUYZEN (1994) constatou que o aumento da temperatura aumenta a velocidade de mortalidade das lagartas contaminadas de C. fumiferana e que o efeito da temperatura foi na proliferação das células vegetativas. Já HWANG et al (1995) afirmam que substâncias, como taninos condensados e glicosídios fenólicos, encontradas nas folhas afetam a patogenicidade do B. thuringiensis var.…”