Abstract Studies were conducted in 1974 and 1975 in naturally infested fields to evaluate the effectiveness of Furadan and Dyfonate against the garden symphylan. Plots (20 x 12 ft) were arranged in pairs and treatments were applied at random in a randomized block design to one plot of each pair and the other was left as a check. Check plots were used to adjust the response in the treated plots for variation in the distribution of symphylans in the fields. Each pair of plots was replicated twice in 1974 and fcJur times in 1975. Granular (10 G) and flowable (4 F) Furadan and Dyfonate were applied with a hand applicator (liquids in I gallon of water) in a 7-inch band to previously marked rows spaced 36 inches apart. Furadan was applied at 1.0 and 2.0 lb a.i./acre and Dyfonate at 2.0 lb a.i./acre. In 1974, four rows of sweet corn (var. Golden Bantam) were planted through the bands immediately after treatment (May 8). In 1975, two rows of sweet corn (var. Jubilee) and two rows of field corn (var. Pioneer 3872) were planted through the bands immediately after treatment (May 14 and May 20 at location one and two, respectively). In 1974, four soil samples (25.4 cm deep) were taken at random with a small spade from each treatment on June 17 and August 6. In 1975, two soil samples were taken at random from each treatment on June 17 and June 30 at location one, and on July 8 and July 16 at location two. Soil samples were placed in plastic bags and symphylans were extracted from the samples in the laboratory by water flotation. In 1974, estimates of sweet corn yield were taken August 27 by picking all ears from the center two rows of each treatment. In 1975, estimates of sweet corn yield were token September 2 from all rows at both locations and estimates of yield of field corn were taken from all rows on September 22.