Evaluation of Homeowner Spray Products for Gypsy Moth Egg Mass Control, 1982

The experimental site was a heavily infested ridge in Frederick Co., Md., before egg hatch in spring. The test materials were applied to individual egg masses until runoff using a 1602 trigger-pump bottle, pressurized aerosol can, or a small paint brush. Some materials were applied to groups of individual egg masses 3 weeks, 2 weeks, and 1 week before hatch. Other materials were tested only once, 2 weeks or 1 week before hatch. Each material-formulation was applied to 20 egg masses. Ten egg masses were brought to the lab where larval hatch and survival were recorded. The remaining 10 were evaluated in the field. Most materials tested resulted in lower survival than the controls. Of the products that were tested on three different dates, the S. C. Johnson products performed significantly better when applied 3 or 2 weeks before hatch than 1 week before hatch. Ficam efficacy was not affected by the time interval between application and hatch. Many of the S. C. Johnson products provided excellent control, as did Ficam at 1 lb/100 gal and 0.5 lb/100 gal. Also among the most efficacious materials were the surfactants Exhault 100, Biofilm, Hydrowet, Triton B-1956, Regulaid, a pine oil (Breath o’Pine), and Neem-seed extract (1:1 in 95% EtOH). Laboratory evaluation allowed accurate 48-h survival counts under artificially controlled temperature and humidity. While field analysis made possible the assessment of product efficacy under realistic natural conditions, only rough estimates of actual mortality could be made. All percentages were transformed to arc sine percentage before analysis.