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ARS Home » Research » Publications at this Location » Publication #65454
Title: 1994-1995 FIELD EVALUATIONS OF GYPCHEK/CARRIER FORMULATIONS

Author
item THORPE, KEVIN
item PODGWAITE, JOHN - USDA FOREST SERVICE
item WEBB, RALPH
item REARDON, RICHARD - USDA FOREST SERVICE
item COOK, STEPHEN - OKLAHOMA BIOL SURVEY

Submitted to: Gypsy Moth News
Publication Type: Government Publication
Publication Acceptance Date: 9/15/1995
Publication Date: N/A
Citation: N/A

Interpretive Summary: The gypsy moth is a serious pest of hardwood forests in the northeastern United States. The gypsy moth virus product, Gypchek, was registered with the U.S. Environmental Protection Agency in 1978 as a general use pesticide to control the gypsy moth. Because it directly affects only the gypsy moth, it has the potential to play an important role in situations where gypsy moth control is needed, but where there must be a high degree of protection of animals other than the gypsy moth. The development of a carrier, or ready-to-spray liquid into which gypchek could be dissolved, is considered to be a potentially important advance in the use of this biological control tactic. The objective of this study was to conduct a field test of a newly-developed commercial carrier at different numbers of applications and application volumes. The study was conducted on potentially defoliating gypsy moth populations in Virginia in 1995. The carrier + gypchek spray provided effective foliage protection at both the one gallon and the 0.5 gallon volumes, and with both single and double applications. The results of this study provide data to assist the effective use of the carrier + gypchek combination against the gypsy moth. This information should also help forest managers, gypsy moth control specialists, and government agencies decide if they should consider this treatment as an option for gypsy moth management.

Technical Abstract: A field test of a commercial carrier for the gypsy moth nuclear polyhedrosis virus product, Gypchek, was conducted in 1995 to test the following treatments: 1) double applications of carrier at one gallon per acre per application; 2) double applications of carrier at 0.5 gallons per acre per application; 3) a single application of carrier at one gallon per acre; 4) double applications of a lignosulfonate-molasses tank mix at two gallons per acre per application; and 5) an untreated control. All treatments except the control included Gypchek at 4 x 10[11] viral occlusion bodies per acre. Larval mortality ranged from 73% with a single application of carrier to 90% with the high volume, double application of carrier. Mortality was significantly lower among larvae collected from plots treated with only a single application. Estimated larval density was 126 per m[2] in the untreated plots, 57 per m[2] in the single application plots, and less than 25 per m[2] in the plots treated with the other treatments. Defoliation in the control plots averaged 38%, which was significantly higher than the 15 to 23% defoliation which occurred in the treated plots. There was no detectable difference between the lignosulfonate molasses tank mix and the double application of carrier at either the 1 gallon or the 0.5 gallon volume.