Impact of Pesticides on Leafminers and Their Associated Parasites on Tomatoes, 1984

Seedlings were transplanted on 10 Jul at the University of California’s South Coast Field Station in Santa Ana, California. Experimental plots were 4 rows wide (5-ft centers) by 40 ft long and separated by a 5-ft buffer. The tomato transplants were sprinkle irrigated for 2 wk, and drip irrigated thereafter. Treatments were replicated 4 times in a randomized complete block design. Weekly applications were initiated at flowering. Application dates included 17, 24, 31 Aug, and 7 and 14 Sep. A tractormounted boom sprayer with 6 nozzles incorporated D3 orifice disks, #25 cores and 50-mesh screens. All treatments included 0.4% spreader-sticker (Leaf Act 40). Leafminer populations were evaluated by weekly counts of larvae and pupae in 4 pupal trays/replicate from 23 Aug through 13 Sep. On 21 Sep, 200 mature-green to ripe fruit were harvested from the center 2 rows of each replicate and examined for internal damage (primarily H. zea), external damage (primarily S. exinua), and K. lycopersicella.