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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Invasive Species and Pollinator Health » Research » Research Project #431855

Research Project: Monitoring Seasonal Dynamics of Two Major Crop Pests and Their Resident Natural Enemies in California

Location: Invasive Species and Pollinator Health

Project Number: 2030-22000-029-23-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Sep 30, 2016
End Date: Sep 30, 2018

Objective:
1) To monitor seasonal population dynamics of spotted wing drosophila (SWD) and generalist parasitoids of SWD in crop fields and adjacent non-crop habitats. 2) To examine whether non-crop habitats act as seasonal refuges for SWD and/or its parasitoids. 3) To survey regions in California for resident natural enemies that use bagrada bug as a host or prey.

Approach:
1) To monitor seasonal population dynamics of spotted wing drosophila (SWD) and generalist parasitoids of SWD in crop fields and adjacent non-crop habitats. 2) To examine whether non-crop habitats act as seasonal refuges for SWD and/or its parasitoids. 3) To survey regions in California for resident natural enemies that use bagrada bug as a host or prey. To monitor SWD numbers and parasitism of SWD, the cooperator will use traps baited with apple cider vinegar and sentinel SWD pupae from laboratory colonies, respectively. Traps and sentinel pupae will be deployed at six sites along transects that extend from strawberry fields into adjacent non-crop habitats containing known hosts of SWD (i.e., blackberry in riparian areas) for one week periods in winter, spring, summer and fall. Numbers of the resident SWD pupal parasitoid Pachycrepoideus vindemiae will be augmented in non-crop habitats at three of these sites in early spring, when numbers of SWD are low and before SWD has appeared in the strawberry fields. Numbers of P. vindemiae will not be released at the three other sites, which will act as controls. Pachycrepoideus vindemiae will be mass-reared for this effort at the UC Kearney Agricultural Research Center, Parlier, CA. To survey resident natural enemies that attack bagrada bug, frozen bagrada bug eggs will be glued to index cards and placed in areas of California with high densities of bagrada bug. Cards will be placed on the ground, where the bagrada bug deposits the majority of its eggs, in both crop fields and patches of known weed hosts of bagrada bug.