Effectiveness of Microbial and Chemical Insecticides in Control of the Colorado Potato Beetle (Coleoptera: Chrysomelidae) on Potatoes and Tomatoes

Abstract

The control of the Colorado potato beetle, Leptinotarsa decemlineata (Say), by formulations of Bacillus thuringiensis (Berliner) (B.t.) and other microbial agents and chemical insecticides was assessed in field plots of potatoes and tomatoes over a 5-year period. Applications of formulations of thuringiensin, the beta exotoxin of B.t., and of B.t. var. son diego (B.t.sd.) to potatoes reduced numbers of larvae of the potato beetle compared with the nontreated check and resulted in yields significantly greater than from the check plots and, in most cases, similar to yields from plots treated with carbofuran. Treatment of tomatoes with B.t.sd. reduced populations of larvae of the Colorado potato beetle compared with the nontreated check and increased yield of nondamaged fruit from plots. An initial application of carbofuran to potatoes or permethrin to tomatoes followed by applications of thuringiensin or B.t.sd. protected potatoes or tomatoes as well as did the chemical insecticide used alone in a treatment program. Applications of preparations of B.t. var. kurstaki or spores of the fungus Beauveria bassiana (Balsamo) Vuillemin or the microsporidium Vairimorpha necatrix (Kramer) did not reduce populations of the beetle.

Delayed efficacy of Beauveria bassiana foliar spray applications against Colorado potato beetle: Impacts of number and timing of applications on larval and next-generation adult populations

“…Results from foliar spray applications have been positive in some small-scale field tests (Fargues et al, 1980;Campbell et al, 1985;Anderson et al, 1988;Poprawski et al, 1997;Lacey et al, 1999), but in other tests, including pilotscale efforts, efficacy has been marginal to poor (Anderson et al, 1988;Jaques and Laing, 1988;Hajek et al, 1987), We conducted small-scale field tests of B. bassiana strain GHA formulated as BotaniGard in the late 1990s and ultimately reached conclusions similar to those of Hajek et al (1987) that multiple, frequent applications of Bb, even via efficient manually-targeted sprayers, could not be relied upon to control larval populations of this difficult pest (Wraight and Ramos, 2002).…”

Synergistic interaction between Beauveria bassiana- and Bacillus thuringiensis tenebrionis-based biopesticides applied against field populations of Colorado potato beetle larvae

“…A preparation of B. thuringiensis containing thuringiensis ( -exotoxin) as the active ingredient was produced in the Soviet Union under the name Bitoxibacillin (Lipa, 1985). Experimental thuringiensin-based preparations also have been tested in the USA (Anderson et al, 1989;Jaques and Laing, 1989). However, the broad-spectrum toxicity of thuringiensin, combined with its teratogenic and mutagenic properties, has limited commercial development.…”