This BIOAg funded project focused on critical knowledge gaps in the use of plant volatiles as attractants for two different beneficial lacewing species (Chrysopa nigricornis and Chrysoperla plorabunda). The purpose was to investigate whether it was possible to manipulate the spatial distribution of natural enemies in agricultural systems to augment biological control in areas with large pest populations of woolly apple aphid (WAA).
Results found spatial effects of the lures increased the activity 8-10 fold compared to control areas, but the effects were limited to less than 3.3 meters from the source tree. Flight activity around the lures was highest at dawn and dusk, and relatively low throughout the rest of the day. In addition, the lures did not result in lacewings spending significant time on the lures, which would
disrupt their population growth and suppression of pest populations. Evaluation of WAA population growth between trees with lures and control trees showed that the lures suppressed colony establishment and growth compared to the control trees, but to date they have not been tested for the ability to reduce high populations. This demonstrates the feasibility of using this approach to attract lacewings to orchards for biological control and justifies further experiments to evaluate the operational factors necessary for commercial adoption.
Funds were leveraged for an additional research grant from the Washington Tree Fruit Research Commission to further research this pest management possibility. More information on these project findings are available HERE. For more information on pest management, visit the WSU Orchard Pest Management Online site.
Principal Investigators: Vincent P. Jones and Conor O’Leary (graduate student).
This article is reprinted from the CSANR 2016 Annual Report.