Biological Effectiveness of Insecticides to Control Cone Beetle in Pinyon Pine Plantations

Abstract

Pinyon pine plantations are attacked by insects that feed on conelets and seeds, a phytosanitary problem that causes economic losses in production. The study evaluated the biological effectiveness (BE) of chemical insecticides to control Conophthorus edulis Hopkins in a Pinus cembroides Zucc. forest plantation. The treatments abamectin (18 g of active ingredient (a.i.) L-1), emamectin benzoate (19.2 g of a.i. L-1), azadirachtin (738.4 g of a.i. L-1) and an untreated check with water were applied randomly with 5 repetitions. The application was repeated 56 days later. Each repetition consisted of applying a treatment to a tree with a cohort of 20 strobili. The BE of the insecticides was determined by the percentage of healthy conelets for each treatment in 8 evaluations: 0, 19, 32, 50, 65, 83, 109 and 144 days. No significant differences were found between treatments at 5% error by the ANOVA F test. Between the months of August and September, general averages were found between 0.25 to 2.5% of attacked conelets. An increase of 21.25% was observed in the average number of dead conelets between the initial and final evaluations in September.