PI(s): Pfeiffer, Douglas G (Co-Project Leader), Kuhar, Thomas P (Co-Project Leader)
Abstract: In spring 2007, we will establish plantings (~0.1 acre) of each of three commercial insectary plant mixes in randomized complete blocks with 4 replications in vineyards in Virginia (The Vineyard at Point Breeze, Belle Haven, VA) tfoster populations of natural enemies.
Description:Our study will record the beneficial arthropods present in three different commercially available beneficial insect habitat seed mixes (Clyde Robin's Border Patrol, Heirloom Seed's Beneficial Insect Mix, and Peaceful Valley's Good Bug Blend) planted around vineyards in Virginia. Identifying what organisms are attracted to the beneficial plants is an important first step in determining the potential impact of the strategy on grape pest management. Potential pests that may be impacted by natural enemies include grape berry moth, aphids, leafhoppers. Seaman et al. (1990) reared several egg parasites from grape berry moth, including one species of Trichogramma, T. pretiosum. While not always present, it was capable of causing the highest level of parasitization. It would be worthwhile trying to modify the habitat to allow greater levels of Trichogramma survival. It is likely that alternative food sources would improve parasite survival. Greater levels of parasitization of cranberry fruitworm by either endemic or released T. pretiosum have been seen in neglected sites. T. minutum adults lived longer and produced more offsping when plant nectar souces were available (in this case, peach extrafloral nectaries). T. dendrolimi and T. maidis attack eggs of the European grape berry moth, Eupoecilia ambiguella; in that species, eggs have been shown to be most attractive to parasites when young; once the head capsule develops, eggs are no longer attractive. Egg-parasitic wasps can also be a mortality factor in sharpshooters that transmit Pierce's disease.