Wireworm Control with Insecticides in Illinois, 1991

Abstract

Abstract The wireworm trial was established near Hutsonville. This site had been planted to popcorn in 1989 and subsequently suffered from a severe infestation of wireworms. Soybeans were planted in 1990. In 1991 the 3 solar bait stations (each a 20-oz mixture of wheat and corn buried 4-6 inches deep) placed in early spring in this field detected an average of 4 wireworms per station. The experimental design was a randomized complete block with 4 replications. Eight check plots were included in each replication and were averaged for the ANOVA. Treatments were applied to single rows (60-ft long) with 30-inch row spacing. Granular insecticides were applied with Noble units mounted on each of the planter units (John Deere 7000 series, 4-row Max-emerge planter). Granules were applied in-furrow or in a 7-inch band ahead of the firming wheels and were incorporated into the soil at planting (1 May). Seed treatments were mixed with seed on the day of planting. On 31 May, stand counts (in 17.3 ft of row) and 2 trench soil samples were taken from each plot. A soil sample consisted of a trench of soil 3.3 ft (length) × 4 inches (width) × 4 inches (depth) that was removed and sifted from each row. Seeds/seedlings in each 3.3 ft of row were examined for wireworm damage and rated according to the following scale: (1) seed/seedling undamaged, (2) seed/seedling damaged but plant established, (3) seed/seedling damaged, with plant showing some signs of stress, and (4) seed/seedling damaged, with no plant establishment. The percentage of damaged plants was calculated from the rating scale.