Publications by authors named "Michael D Doerr"

The response of field-collected populations of the obliquebanded leafroller, Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae), to chlorantraniliprole, spinetoram, spinosad, and azinphosmethyl was assessed using a diet incorporation bioassay. Populations of obliquebanded leafroller were collected from nine orchards in Chelan, Douglas, Grant, and Okanogan counties of Washington. The neonates of the F1 or F2 generation were used in all assays.

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The obliquebanded leafroller, Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae), is a serious pest of apples and other tree crops throughout North America. A review of temperature dependent development and models show that five different lower thresholds for development are published and used as the basis of heat-driven phenology models. We present a small lab data set of C.

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The phenology of Lacanobia subjuncta (Grote & Robinson) (Lepidoptera: Noctuidae) was investigated in 30 apple orchards in central Washington state and northeastern Oregon from 1998 to 2001 (57 total orchard-yr). Adult captures in pheromone-baited traps were fit to a Weibull distribution to model emergence of the first and second generations. Initial capture of first generation adults was observed at 216.

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Article Synopsis
  • Insecticide bioassays conducted on leafrollers, Choristoneura rosaceana and Pandemis pyrusana, revealed resistance levels to azinphosmethyl among field populations compared to laboratory colonies.
  • Resistance to azinphosmethyl ranged from 5.2 to 26.8 times higher in C. rosaceana and 8.4 to 24.9 times in P. pyrusana from commercial orchards.
  • Cross-resistance was primarily noted between azinphosmethyl and insect growth regulators like tebufenozide and methoxyfenozide, while no cross-resistance was observed with chlorpyrifos, and responses to spinosad and indoxacarb
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Bioassays of Lacanobia subjuncta (Grote and Robinson) larvae established baseline LC50 values and identified the potential of reduced-risk, organophosphate replacement and naturally derived insecticides (eg chloronicotinyls, spinosyns, oxadiazines, insect growth regulators, microbial insecticides and particle films) to control this pest. The toxicities of these products were compared with those of organophosphate, carbamate, chlorinated cyclodiene and synthetic pyrethroid insecticides used in the management of lepidopteran pests in Washington apple orchards. Field trials were conducted comparing candidate insecticides to conventional alternatives.

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