Submitted to: Silverleaf Whitefly: 1997 Supplement to the Five Year National Research and
Publication Type: Abstract Only
Publication Acceptance Date: January 28, 1997
Publication Date: N/A
Technical Abstract: Research was conducted to provide supporting information on work conducted in 1994 and 1995 on the impact of a foliar insecticide on abundance of native whitefly parasitoids in vegetables. Crops of cantaloupe, collard, and tomato were each established in three fields. Half of each crop within each field was treated bi-weekly with foliar imidacloprid (Provado) at 0.1 lbs ai/acre for a total of 5 treatments over the season. No other pesticide was used after the crops were planted. Yellow sticky cards were placed in each subplot. These were retrieved after one week and the number of captured adult Bemisia argentifolii and its parasitoids were counted in the laboratory. The majority of the captured parasitoids were Eretmocerus sp. (42%), Encarsia nigricephala (28%), and Encarsia pergandiella (27%). A few Encarsia strenua and Encarsia quaintancei were also captured. The abundance of B. argentifolii and the parasitoids varied among fields. Across all fields and crops, ca. 65% of the parasitoids were captured in the untreated plots compared with the imidacloprid treated plots. Persistence of parasitoids in the treated crops is consistent with what we found in 1994 and 1995 using chlorpyrifos (Lorsban) and Provado, respectively.