Browsing by Author "MacRae, Ian V."

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    Floral Plantings in Large-Scale Commercial Agroecosystems Support Both Pollinators and Arthropod Predators
    Middleton, Eric G.; MacRae, Ian V.; Philips, Christopher R. (MDPI, 2021-01-21)
    Beneficial insect populations and the services that they provide are in decline, largely due to agricultural land use and practices. Establishing perennial floral plantings in the unused margins of crop fields can help conserve beneficial pollinators and predators in commercial agroecosystems. We assessed the impacts of floral plantings on both pollinators and arthropod predators when established adjacent to conventionally managed commercial potato fields. Floral plantings significantly increased the abundance of pollinators within floral margins compared with unmanaged margins. Increased floral cover within margins led to significantly greater pollinator abundance as well. The overall abundance of arthropod predators was also significantly increased in floral plantings, although it was unrelated to the amount of floral cover. Within adjacent potato crops, the presence of floral plantings in field margins had no effect on the abundance of pollinators or predators, although higher floral cover in margins did marginally increase in-crop pollinator abundance. Establishing floral plantings of this kind on a large scale in commercial agroecosystems can help conserve both pollinators and predators, but may not increase ecosystem services in nearby crops.
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    Managing Colorado Potato Beetle Insecticide Resistance: New Tools and Strategies for the Next Decade of Pest Control in Potato
    Huseth, Anders S.; Groves, Russell L.; Chapman, Scott A.; Alyokhin, Andrei; Kuhar, Thomas P.; MacRae, Ian V.; Szendrei, Zsofia; Nault, Brian A. (Entomological Society of America, 2014-12-01)
    Neonicotinoid insecticides have been the most common management tool for Colorado potato beetle, Leptinotarsa decemlineata (Say), infestations in cultivated potato for nearly 20 yr. The relative ease of applying neonicotinoids at planting coupled with inexpensive, generic neonicotinoid formulations has reduced the incentive for potato growers to transition from these products to other mode of action (MoA) groups for early-season L. decemlineata control. Continuous use of neonicotinoids has resulted in resistant L. decemlineata populations in some production areas of the eastern United States. Continued reliance on neonicotinoids will accelerate L. decemlineata resistance development and result in additional insecticide inputs to manage these populations. Resistance management recommendations for L. decemlineata have focused on rotation of insecticides within the growing season. Growers using at-plant neonicotinoids for early-season L. decemlineata control are encouraged to rotate MoAs for later generations to delay resistance development. Although this short-term insecticide rotation has likely prolonged the utility of neonicotinoid insecticides, reducing reliance on a single MoA soil application at planting will improve the longevity of newer, more reduced-risk alternatives. The objectives of this article are twofold: 1) to provide a review of the current status of L. decemlineata neonicotinoid resistance, and 2) to propose long-term resistance management strategies that arrange reduced-risk MoA groups into several, multiyear sequences that will maximize L. decemlineata control and reduce the probability for resistance development. This recommendation maintains practical and economical approaches for L. decemlineata control, but limits reliance on any single MoA group to minimize selection pressure for resistance development.