Laboratory and field studies in Chile on the control of Epinotia aporema (Lepidoptera: Olethreutidae) and Rachiplusia nu (Lepidoptera: Noctuidae) on Phaseolus vulgaris beans with growth regulators, Bacillus thuringiensis, and avermectin

Abstract

Laboratory and field trials were conducted to evaluate the effectiveness of control of the larvae of Rachiplusia nu and Epinotia aporema (Lepidoptera: Noctuidae, and Olethreutidae, respectively), on Phaseolus vulgaris beans, by avermectin, Bacillus thuringiensis, diflubenzuron, triflumuron, and endosulfan. Two days after application in the laboratory, endosulfan resulted in 90% mortality of R. nu; avermectin, B. thuringiensis, triflumuron and diflubenzuron caused 48, 36, 28, and 16% mortality, respectively, on R. nu larvae. Triflumuron and diflubenzuron had a low initial activity against the larvae of E. aporema (10 and 4% mortality 2 days after application). All treatments obtained high final mortality levels (84–98%) of R. nu. Diflubenzuron and triflumuron caused slow initial effects on R. nu and E. aporema, but a high final cumulative mortality, in part attributable to malformation of pupae. In the field trial, all treatments had generally fewer larvae than the control. Fewer pods were damaged by E. aporema with endosulfan and avermectin 12 days after application than in the other treatments. The percentage of damaged pods increased largely thereafter in the controls, reaching 16.3% 26 days after the application date. Triflumuron was the only treatment that did not differ from the control 15 days after application, corroborating its slow insecticide action on E. aporema in the laboratory.