BioControl (2001) 46, 419-426

L.T. Kok and J.A. Acosta-Martinez (2001)
Differential susceptibility of Cotesia orobenae, a parasitoid of the cross-striped cabbageworm, to commonly used insecticides in Cruciferae
BioControl 46 (4), 419-426
Abstract: The larval endoparasitoid Cotesia orobenae Forbes (Hymenoptera: Braconidae) is an effective natural enemy of the cross-striped cabbageworm, Evergestis rimosalis (Guenée) (Lepidoptera: Pyralidae), in southwest Virginia. Routine use of insecticides to control Plutella xyostella (L.) and other lepidopterous larvae in commercial plantings of cabbage, cauliflower and broccoli can disrupt populations of C. orobenae, causing localized outbreaks of the cross-striped cabbageworm to occur. Since the use of insecticides is the choice insect pest management tactic of growers in southwest Virginia, we examined the differential susceptibility of this hymenopteran parasitoid to four frequently used pesticides, methomyl (carbamate), permethrin and esfenvalerate (pyrethroids), and Bacillus thuringiensis Berliner subsp. Kurstaki (bacterium). Filter paper dipped into four different concentrations of methomyl, permethrin, and esfenvalerate were left to dry and then exposed to C. orobenae. Two concentrations of B. thuringiensis were also tested by contact bioassay, and an additional test was conducted by mixing B. thuringiensis with honey and water as a food source for the insects. Ten adult parasitoids were exposed to each treatment, replicated 10 times. Significant differences in mortality among insecticides tested (p < 0.05) were found. Most toxic to C. orobenae was permethrin, followed by esfenvalerate and methomyl. The parasitoid was not affected by B. thuringiensis when placed in contact with B. thuringiensis-treated broccoli leaves, or by ingestion of honey mixed with it (p < 0.05).
(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): Loke T. Kok

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
health/environmental effects of pesticides
Research topic(s) for beneficials or antagonists:
resistance to pesticides

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Plutella xylostella		U.S.A. (NE)
	Evergestis rimosalis		U.S.A. (NE)
Cotesia orobenae (parasitoid)	Evergestis rimosalis		U.S.A. (NE)