Pesticide mixtures can reduce the rate at which insects evolve pesticide resistance. However, with live biopesticides such as the naturally abundant pathogen Bacillus thuringiensis (Bt), a range of additional biological considerations might affect the evolution of resistance. These can include ecological interactions in mixed infections, the different rates of transmission post-application and ...

The following stress factors were tested for their effect on the susceptibility of Plutella xylostella (L.) to Bacillus thuringiensis Berliner: (a) exposure to low doses of the synthetic pyrethroid cypermethrin, (b) treatment with low doses of the secondary plant compound, azadirachtin and (c) development on partially resistant cabbage cultivars. B. thuringiensis-related mortality of cypermethr...

XIN-GENG WANG, JOHN DUFF, MICHAEL A. KELLER, MYRON P. ZALUCKI, SHU-SHENG LIU AND PETER BAILEY School of Agriculture and Wine, University of Adelaide, SA 5064, Australia; Institute of Applied Entomology, Zhejiang University, Hangzhou 310029, China; Gatton Research Centre, Queensland Department of Primary Industries, QLD 4343, Australia; School of Life Sciences, University of Queensland, QLD 4072...

We report the occurrence of natural enemies of Plutella xylostela (L.) in organically farmed kale in Pernambuco, Brazil. Seven natural enemies were observed parasitizing or preying on larvae and pupae of P. xylostella--three parasitoids: Cotesia plutellae Kurdjumov (Hym.: Braconidae), Conura pseudofulvovariegata (Becker) (Hym.: Chalcididae) and Tetrastichus howardi (Olliff) (Hym.: Eulophidae), ...

Although the mode of action of Cry1A toxins produced by Bacillus thuringiensis is fairly well understood, knowledge of the molecular mechanisms by which lepidopteran species have evolved resistance to them is still in its infancy. The most common type of resistance has been called "Mode 1" and is characterized by recessive inheritance, >500-fold resistance to and reduced binding by at least one...

Attempts to control diamondback moth Plutella xylostella (L.) using insect parasitoids have not been entirely successful. Parasitoids which have been utilized include Diadegma species and Cotesia plutellae. A better understanding of the systematics of these Hymenoptera could lead to their more effective exploitation in biological control. Diadegma is a very large and difficult genus of lchneumo...