Advancing integrated pest management (IPM) strategies for cucumber beetles in California

On-Demand

Presenting Author(s)

Jasmin Ramirez Bonilla

University of California
Sacramento, California

Co-Author(s)

AV

Amber Vinchesi-Vahl

University of California Cooperative Extension
Yuba City, California
Donald C. Weber

USDA-ARS
Beltsville, Maryland
Ian Grettenberger

University of California-Davis
Davis, California

The western striped cucumber beetle (WStrCB), Acalymma trivittatum, and the western spotted cucumber beetle (WSptCB), Diabrotica undecimpunctata undecimpunctata, are key pests of muskmelons in Northern California. Management strategies are limited to broad-spectrum insecticides and costly cultural methods. Although pest managers monitor and scout for these beetles, they are not as effective as possible due to the lack of knowledge on the characterization of the overwintering and non-crop habitat use of the WStrCB. In the early spring of 2020, we conducted descriptive habitat surveys to characterize overwintering and non-crop habitat for the WStrCB. Samples were taken weekly at two farms using yellow sticky cards with a floral lure, sweep net sampling, and visual counts. We also documented weed assessments (by percent cover) to associate weed species with beetle abundance from visual counts. Additionally, we evaluated the efficacy of an aggregation pheromone (vittatalactone) of the eastern striped cucumber beetle, Acalymma vittatum, the sister species of the WStrCB. We deployed clear-sticky traps either baited with vittatalactone or unbaited and recorded beetle counts. Preliminary results indicated that there is a strong preference for broadleaf weeds over grasses. However, no significant preference for specific weed species was determined. Results for the pheromone trial showed that vittatalactone is attractive to the WStrCB and WSptCB. Having a clearer understanding of the overwintering and non-crop habitat use can optimize monitoring and scouting efforts for the WStrCB. And the evaluation of vittatalactone poses opportunities to develop effective IPM strategies for the management of these beetles.