Biocontrol Science and Technology (1999) 9, 487-498

B. Amiri, L. Ibrahim and T.M. Butt (1999)
Antifeedant properties of destruxins and their potential use with the entomogenous fungus Metarhizium anisopliae for improved control of crucifer pests
Biocontrol Science and Technology 9 (4), 487-498
Abstract: Destruxins A, B and E, produced by the entomogenous fungus Metarhizium anisopliae, are insecticidal but comparatively low doses have antifeedant properties. Treatment of cabbage leaf discs with destruxins significantly reduced feeding by larvae of Plutella xylostella and Phaedon cochleariae in both choice and no-choice assays. The Antifeedant Index (AI) was dose related and there were significant differences between treated and untreated leaves. The AI and acute toxicity assays suggest that insect death was due to a combination of the starvation and toxicity effects of destruxins. In whole plant experiments, adults and larvae of P. cochleariae were found to be more susceptible to infection by M. anisopliae V245 if it was used in conjunction with a crude destruxin mixture. Destruxins drove larvae off the plant, irrespective of which leaf surface was treated. Adults could be forced to the adaxial or abaxial surface of leaves using the crude destruxin. Mortality was usually more consistent and generally greater if adults were forced to abaxial than adaxial surfaces inoculated with the fungus. High humidity on the abaxial surface favoured conidia germination and infection. Mortality was also greater for adults dusted with the pathogen and forced to the abaxial rather than to the adaxial leaf surface. The increased movement and starvation associated with destruxin treatment may also have stressed the insects making them more susceptible to infection.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Ludmilla Ibrahim, Tariq M. Butt

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
control - general
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Plutella xylostella	Cabbage (Brassica oleracea)
	Phaedon cochleariae	Cabbage (Brassica oleracea)
Metarhizium anisopliae (entomopathogen)	Phaedon cochleariae	Cabbage (Brassica oleracea)