Phosphite is a general term used to describe the salts of phosphorous acid H3PO3. It is effective in suppressing a number of plant diseases caused by oomycetes and has been shown to reduce populations of several insect species. We investigated the effects of phosphite on the Colorado potato beetles in the field and laboratory. Beetle […]
Novaluron is a chitin synthesis inhibitor (a benzoylphenyl urea) that kills larval stages and causes reversible cessation of laying viable eggs in adults of the Colorado potato beetle, Leptinotarsa decemlineata (Say). Previous studies also suggest that it has ovicidal properties, but not on all tested egg masses. We investigated if egg maturity at the time of exposure
Response to odours plays an important role in resource location by natural enemies, particularly by parasitoid wasps. While a considerable research effort has been dedicated to studying the effects of insecticide intoxication on natural enemy search behaviour, it is yet unknown if the odours themselves interfere with distant chemoreception. We investigated this issue using the
The Colorado potato beetle, Leptinotarsa decemlineata (Say), is one of the most damaging insect pests of potato. Novaluron is a relatively new benzoylphenyl urea insect growth regulator with good activity against this pest. Earlier studies revealed that feeding on potato foliage treated with novaluron induces reversible egg hatch inhibition in adult Colorado potato beetles. We investigated if
The Colorado potato beetle, Leptinotarsa decemlineata (Say), is widely regarded as the most important insect defoliator of potatoes. Its current range covers about 16 million km2 in North America, Europe, and Asia and continues to expand. This insect has a complicated and diverse life history, which is well-suited to agricultural environments, and makes it a complex and challenging
BACKGROUND: Novaluron is a benzoylphenyl urea chitin synthesis inhibitor that combines good activity against larval stages of the Colorado potato beetle, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), with low mammalian toxicity. Previous studies suggest that it has deleterious sublethal effects on adults. RESULTS: Continuous exposure of adult Colorado potato beetles to novaluron-treated foliage as both ovipositional and feeding substrate
Reduced fitness among resistant versus susceptible individuals slows resistance evolution and makes it easier to manage. A loss of resistance costs could indicate novel adaptations or mutations contributing to resistance. We measured costs of resistance to imidacloprid in a Massachusetts resistant population compared with a Massachusetts susceptible population in 1999 in terms of fecundity, hatching
One of the major challenges in managing the Colorado potato beetle, Leptinotarsa decemlineata (Say) is its remarkable ability to develop insecticide resistance to virtually every chemical that has ever been used against it. Resistance is particularly common throughout northeastern U.S. as far north as Maine. The first instances of resistance to imidacloprid have been already reported from
Repeated use of neonicotinoid insecticides has resulted in the first reported cases of Colorado potato beetle (Leptinotarsa decemlineata (Say)) resistance to imidacloprid. In the laboratory we determined susceptibility of the imidacloprid-resistant Colorado potato beetles from a population in Southern Maine to other insecticides currently registered for use on potato. This population was about 30-fold resistant to