Effect of dose and trap type on captures of striped and spotted cucumber beetles using synthetic vittatalactone

Authors: PASTEUR, KAYLA - Former ARS Employee; Haber, Ariela; Weber, Donald

Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/19/2023
Publication Date: 8/3/2023
Citation: Pasteur, K., Haber, A.I., Weber, D.C. 2023. Effect of dose and trap type on captures of striped and spotted cucumber beetles using synthetic vittatalactone. Environmental Entomology. https://doi.org/10.1093/ee/nvad075.
DOI: https://doi.org/10.1093/ee/nvad075

Interpretive Summary: Striped and spotted cucumber beetles are serious pests of vegetable crops, especially cucurbits (squash, cucumbers, pumpkins, and melons). Pesticide applications, directed against cucumber beetles and other cucurbit insect pests, can jeopardize bee pollination that is essential to the crop yield. Alternative selective tactics, including behavioral control for managing cucumber beetles, are needed in order to improve pest management. The striped cucumber beetle pheromone, called vittatalactone, is attractive to both male and female adults, and is also attractive to spotted cucumber beetles. We tested different doses of synthetic vittatalactone in Maryland, and different types of traps, to determine which would be most effective in monitoring and/or suppressing these two beetle pest species. Both species' capture increased with pheromone dose, and traps varied widely as to how many beetles each type caught. The boll weevil trap baited with vittatalactone dose of 1 milligram was superior to other non-sticky traps, and did not catch bees and other nontarget insets that some traps, especially yellow ones, did. These findings indicate that the synthetic pheromone vittatalactone will be useful to the monitoring and possibly mass trapping or baits for both species of cucumber beetles, and thus to help manage the cucurbit pest complex in North America. The results will be of interest to researchers and pest managers, as well as pheromone providers, in regard to using behavioral pest control for protection of this important group of vegetable crops.

Technical Abstract: Vittatalactone, the aggregation pheromone of the striped cucumber beetle, Acalymma vittatum (F.) (Coleoptera: Chrysomelidae) was attractive to spotted cucumber beetles (Diabrotica undecimpunctata howardi Barber) as well as striped cucumber beetles in field trapping experiments in Maryland, and both showed a strong dose response during experiments in May-June and October 2020. Among 12 trap types tested, captures during a two-week experiment in June, using 1mg mixed vittatalactone, sticky panel traps caught the most of each species, with baited traps exceeding unbaited traps by >8-fold for striped and >2-fold for spotted, and with significant response to yellow vs clear color absent in striped, but strong in spotted. Among non-sticky traps, those with yellow or yellow-green exceeded those without for both beetle species, and a ground-placed boll weevil trap captured the most striped cucumber beetles. Bucket-style traps caught excessive non-target bumblebees (Bombus spp.) if yellow, and few beetles, if all green. Rubber septa research lures were attractive for at least two weeks when deployed with sticky traps. Results allow field monitoring with a choice of sticky and non-sticky traps and a suggested lure loading of 1 mg mixed vittatalactone, containing approximately 90 µg of active isomer of vittatalactone. These findings contribute to multi-species behavioral monitoring and control as a component of integrated pest management in cucurbit crops.