Spotted cucumber beetle (Diabrotica undecimpunctata howardi) is attracted to vittatalactone, the pheromone of striped cucumber beetle (Acalymma vittatum)

Authors: Haber, Ariela; PASTEUR, KAYLA - Former ARS Employee; Guzman, Filadelfo; Boyle, Sean; KUHAR, THOMAS - Virginia Polytechnic Institution & State University; Weber, Donald

Submitted to: Journal of Pest Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/8/2022
Publication Date: 1/3/2023
Citation: Haber, A.I., Pasteur, K., Guzman, F., Boyle, S.M., Kuhar, T.P., Weber, D.C. 2023. Spotted cucumber beetle (Diabrotica undecimpunctata howardi) is attracted to vittatalactone, the pheromone of striped cucumber beetle (Acalymma vittatum). Journal of Pest Science. https://doi.org/10.1007/s10340-022-01586-1.
DOI: https://doi.org/10.1007/s10340-022-01586-1

Interpretive Summary: Spotted cucumber beetle (also known as southern corn rootworm) is a pest feeding on many crops, including cucurbits, corn, peanuts, beans, and many other crops and wild plants, particularly in the southeastern USA. On cucurbit crops, it occurs with striped cucumber beetle (Acalymma vittatum), and both are key pests which vector bacterial wilt of cucurbits, a destructive pathogen. Sustainable pest management, reducing pesticide applications directed at cucumber beetles, is needed for cucurbits (squash, melon, pumpkin, and cucumber) and other crops. We made and deployed the pheromone of striped cucumber beetle, vittatalactone, to determine its attractiveness in the field in Maryland and Virginia. Not only did traps capture both male and female striped cucumber beetles, as expected, but they also attracted both male and female SPOTTED cucumber beetles, representing cross-attraction of this species to vittatalactone. These findings suggest 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 multiple species of 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: Spotted cucumber beetle (Diabrotica undecimpunctata howardi; also known as southern corn rootworm) is a pest feeding on many crops, including cucurbits, corn (maize), peanuts, beans, and other crops and wild plants in southeastern North America. On cucurbit crops, where it co-occurs with striped cucumber beetle (Acalymma vittatum), both are key pests that vector Erwinia tracheiphila, a destructive pathogen that causes bacterial wilt. Here we deployed synthetic vittatalactone, the male-produced aggregation pheromone of A. vittatum, as lures in the field, to measure attraction of the target and non-target insects. Both sexes of D. u. howardi were strongly attracted to the vittatalactone lures (5 to 7.5-fold compared to blank trap) throughout the growing season in Maryland and Virginia, USA. Moreover, D. u. howardi was more attracted to live A. vittatum males feeding on squash plants, than to plants with females or without any beetles, confirming the genuine organismal cross-attraction between these two key pests. The kairomonal attraction to vittatalactone suggests that it functions as a “keystone semiochemical,” mediating the colonization of cucurbits by multiple herbivore species. Such cross attraction could allow for use of vittatalactone in management of multiple pest species, with potential reduction of pesticide use in cucurbit crops.