R. C. Reardon

Summary of efficacy evaluations using aerially applied Gypchek® against gypsy moth in the U.S.A.

Abstract Gypchek®, the gypsy moth (Lymantria dispar L.) nucleopolyhedrosis virus product, is manufactured by the United States Department of Agriculture (USDA) Forest Service, and Animal and Plant Health Inspection Service under controlled conditions in a laboratory strain of gypsy moth larvae. Gypchek was registered with the U.S. Environmental Protection Agency in 1978 as a general use pesticide to control gypsy moth. This product has been the subject of intense research and development targeted toward maximizing efficacy while minimizing the cost of production and application. The current Gypchek tank mix is applied at 1.25 × 1012occlusion bodies (OBs) per hectare for each of two applications (3‐days apart) at 18.7 litres/ha per application.

Bacillus thuringiensis field applications: Effect of nozzle type, drop size, and application timing on efficacy against gypsy moth

Abstract In a series of recent studies, we evaluated the influence of delivery systems, drop size and application timing on the efficacy of aerially applied Bacillus thuringiensis against gypsy moth infestations. Use of different nozzle systems including Micronair, Flat Fan or Twin Jet, did not appear to result in significant differences in Bt coverage efficiency, foliage protection or population reduction. Nor was there any significant difference in population reduction when Bt was applied at two different drop sizes with volume median diameters of 110 and 163 μm. The efficacy of different formulations on larval populations were similar when used against the younger 1st and 2nd instar but differed when treatment was delayed until the population matured to the 3rd and 4th instar stages.

Two consecutive yearly applications of orthene medicaps increase protection of grand fir against Western Spruce budworm

Abstract A random sample of Douglas-fir, Pseudotsuga menziesii var. glauca (Beissn.) Franco, and grand fir, Abies grandis (Dougl.), in Idaho in the United States, treated with Orthene Medicaps (acephate) in 1979 was treated again in 1980. One year after the second treatment in 1980, twice-treated (treated in 1979 and 1980) and once-treated (treated only in 1979) grand fir had significantly fewer western spruce budworm larvae per 100 buds than did control trees, and twice-treated grand fir had significantly fewer larvae than did once-treated. Defoliation of new shoots on twice-treated and once-treated grand fir was significantly less than that on control trees; defoliation did not differ significantly between twice-treated and once-treated trees for either species. Residues of acephate and methamidophos, its metabolite, monitored in midcrown foliage were detected 1 year after treatment.

Effects of treating western spruce budworm populations on grand fir and Douglas-Fir with acephate, carbofuran, dimethoate, oxydemeton-methyl, and methamidophos☆

Abstract Systemic implantation cartridges containing liquid formulations of acephate or methamidophos provided 98% and 90% population reduction of western spruce budworm larvae on grand fir. Acephate residue levels in midcrown foliage reached laboratory determined LC 90 values for western spruce budworm larvae within 5 days after treatment. Medicap cartridges containing powdered formulations of carbofuran or dimethoate and Mauget injector units containing a liquid formulation of oxydemeton-methyl provided inadequate population reduction: whereas, Medicaps containing a powdered formulation of acephate provided 93% population reduction. Acephate residue levels in midcrown foliage were sufficient to cause mortality of western spruce budworm larvae by 20 days after treatment.