BioControl (1998) 43, 65-75

Angelika Hilbeck, Craig Eckel and George G. Kennedy (1998)
Impact of Bacillus thuringiensis - insecticides on population dynamics and egg predation of the Colorado potato beetle in North Carolina potato plantings
BioControl 43 (1), 65-75
Abstract: Field studies to assess the impact of Bacillus thuringiensis var. tenebrionis (Btt)-insecticides on Colorado potato beetle populations, egg survivorship and levels of predation on egg masses were conducted in replicated field research plots during two years. Stage-specific abundance of the Colorado potato beetle and predation on egg masses were monitored in Btt-treated and untreated potato plots in both years. The Btt-treatments significantly reduced densities of large (third and fourth instar) Colorado potato beetle larvae. The densities of large larvae remained below 0.5 and 3 per plant in the Btt-treatment while peak densities of 4.5 and 21 large larvae per plant occurred in the untreated control in 1992 and 1993, respectively. Regular sampling of egg masses indicated that predation rates in Btt-treated and untreated plots did not differ significantly although, in 1993, predation rates of up to 100% were recorded, only in Btt-treated plots. In a predator exclusion study carried out in 1992, survivorship of protected eggs was consistently higher than of eggs exposed to predation. Seasonal survivorship of exposed eggs was significantly lower in the Btt-treated than in untreated plots. Btt insecticides for control of Colorado potato beetles provided direct protection of the crop and were compatible with naturally-occurring biological control of Colorado potato beetle eggs due to predation.
(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): Angelika Hilbeck, George G. Kennedy

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
non-target effects/fate in environm.

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Leptinotarsa decemlineata	Potato (Solanum tuberosum)
Bacillus thuringiensis var. tenebrionis (entomopathogen)	Leptinotarsa decemlineata	Potato (Solanum tuberosum)