Three different control methods, row cover, staggered plantings, and the release of a parasitic wasp, Pediobiusfoveolatus, were used to test effectiveness at controlling Mexican bean beetle (MBB) infestations on snap beans. The study consisted of six plots, on five different farms in the Morgantown, W. Va. area, three with and three without the application of the control methods. Releases of 15 adults and 100 larvae during flowering of the bean crop occurred at each plot. Weekly counts of the three MBB life stages, parasitized MBB larvae, and bean yields were taken. The results showed that the release of the parasitic wasp maintained the MBB populations below economic thresholds throughout the growing season. The average yield from plots that received wasp treatments was 34.2 kg, compared to 15.2 kg harvested from untreated plots. Plots that received row cover treatments were shown to be slightly more effective than staggered plantings at controlling MBB populations. Row cover plots yielded an average of 15.3 kg, in comparison to the 11.8 kg yield from untreated plots, while staggered plantings in treated plots yielded 9.5 kg, compared to 6.0 kg from untreated plots. End of season MBB populations in treated plots consisted of 75 adults, 57 pupae, 275 larvae, and 94 parasitized larvae compared to untreated populations, 98 adults, 214 pupae, 420 larvae on average. In conclusion, increased yields can likely be correlated to decreased MBB populations, indicating the release of P. foveolatusas a viable option for control of MBB, especially in organic systems.
Evaluation of Foliar Insecticides for the Control of Mexican Bean Beetle on Snap Beans, 2015*
