Acephate Reduces Populations of Needlemining Larch Casebearer in Laboratory

摘要

Acephate was effective in reducing populations of needlemining larch casebearer (Coleophora laricella) in potted larch (Larix occidentalis) seedlings in the laboratory. A dose range of 9 to 11 g/ha resulted in 50 percent mortality, and one of 34 to 43 g/ha in 90 percent mortality. Because specific densities of needlemining larvae in live larch seedlings were necessary to increase the precision of the observations, rearing procedures were developed to infest groups of seedlings. The optimum density and distribution of eggs were obtained with small (25 by 30 by 41 cm) cages, screened on three sides and the top, and holding 2 to 4 trees, infested for 3 to 5 days with 10 to 75 adult moths collected without regard to sex.