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Acute and sublethal toxicity of novaluron, a novel chitin synthesis inhibitor, to Leptinotarsa decemlineata (Coleoptera: Chrysomelidae)

Author:
Cutler, G.C., Scott-Dupree, C.D., Tolman, J.H., Harris, C.R.
Source:
Pest management science 2005 v.61 no.11 pp. 1060-1068
ISSN:
1526-498X
Subject:
mechanism of action, ovicides, insect pests, biosynthesis, insecticides, longevity, oviposition deterrents, insecticidal properties, Solanum tuberosum, plant pests, novaluron, Leptinotarsa decemlineata, toxicity, insect control, mortality, chitin, larvae, Canada
Abstract:
The acute and sublethal toxicities of novaluron, a novel chitin synthesis inhibitor, to a laboratory-reared insecticide-susceptible strain of Colorado potato beetle, Leptinotarsa decemlineata (Say), were determined. Novaluron exhibited excellent residual (120 h LC50 = 0.42 mg litre(-1)) and good direct contact (120 h LC50 = 27 mg litre(-1)) activity against second-instar larvae (L2). Hatch of eggs exposed by direct contact to novaluron solutions greater than or equal to 100 mg litre(-1) was significantly reduced, as was the ability of emerged first-instar larvae to moult. L2 from eggs exposed to greater than or equal to 100 mg litre(-1) novaluron weighed significantly less (P < 0.0001) than those from untreated eggs. However, L2 from eggs treated with 1 mg litre(-1) novaluron weighed significantly more (P less than or equal to 0.05) than those from untreated eggs, suggesting novaluron can have a hormetic effect on L decemlineata larval development. Leptinotarsa decemlineata mating pairs fed foliage treated with novaluron at 25 or 75 g AI ha(-1) produced approximately 25% fewer egg masses and eggs per mass. Hatch of eggs on treated foliage was almost completely suppressed, and longevity of male beetles was reduced by approximately 50% when fed foliage treated with novaluron at 75 g AI ha(-1).
Agid:
679506