Field test with helicopter applications of Gardona against gypsy moth in Pennsylvania

Abstract

In 1972, Gardona® WP was field tested against the gypsy moth, Porthetria dispar (L.), in Pennsylvania. Treatments of 1 gal/acre were applied by helicopter on six 100-acre plots, three at 1 pound AI/gal and three at 1.5 pound Al/gal. Check subplots of 0.1-acre were established throughout the area. Before and after spraying, evaluations were made by counting all visible egg masses and estimating defoliation to the nearest 10 percent. Kromekote cards and aluminum plates were used for qualitative and quantitative spray-deposit assessment. Leaves, soil, and water samples were collected at 1, 3, 6, 12, and 24 days after spraying for residue analysis. Analytical methods for determining residues are presented. Increases in both egg-mass density and percentage of defoliation were found after all treatments, Analysis showed no significant differences between the two doses nor between either of the two doses and the check. The kromekote cards and aluminum plates revealed minimal coverage (drops/cm²) and deposits (gpa) at ground level. Data suggest that Gardona failed to affect the gypsy moth because (1) the study area had above-average precipitation, (2) the spray deposit and residue were highly variable, and (3) the residue dissipated rapidly from the leaves.

Citation

Barger, Jack H.; Helrich, Kenneth. 1975. Field test with helicopter applications of Gardona against gypsy moth in Pennsylvania. Res. Pap. NE-314. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 6p.