Evaluation of insecticides for the control of Melanaphis sacchari (Zehntner, 1897) (Hemiptera: Aphididae) in Sorghum bicolor (L.) Moench (Poales: Poaceae) under greenhouse conditions

Abstract

The yellow sugarcane aphid, Melanaphis sacchari (Zehntner), is an important pest due to its high reproductive capacity and the damage it causes by feeding on plant sap. The objective of this study was to evaluate the efficacy of the insecticides sulfoxaflor, spirotetramat, flupyradifurone, and imidacloprid, applied at different rates, for the control of M. sacchari in sorghum under greenhouse conditions. Two experiments were conducted using a randomized complete block design with 13 treatments and six replicates. Aphid abundance per leaf, biological efficacy, and dry weight of treated plants were evaluated. All insecticides reduced aphid populations compared with the control. At 24 h after application, sulfoxaflor and imidacloprid achieved efficacy rates of up to 93.81% and 96.26%, respectively, whereas at 72 h, several treatments exceeded 98% efficacy. From 5 days after application onward, no aphids were recorded in the insecticide-treated treatments. In Experiment I, dry biomass ranged from 48.57 to 56.23 g with spirotetramat, compared with 31.5 g in the control; in Experiment II, flupyradifurone recorded values ranging from 44.73 to 56.93 g, with no significant differences. No consistent dose-response relationship was observed.