Integrated Management of Sugarcane Aphid, Melanaphis sacchari (Hemiptera: Aphididae), on Sorghum on the Texas High Plains

Abstract

The sugarcane aphid, Melanaphis sacchari (Hemiptera: Aphididae), is an important pest of sorghum (Sorghum bicolor (L.) Moench) and sugarcane, (Saccharum officinarum L.) in the southern United States and in many parts of the world. Recent invasion by this prolific pest has created demand for evaluation of insecticides that also are favorable for conservation of natural enemies. The objective of this study was to compare currently recommended insecticides in combination with predatory lady beetles to develop a strategy to manage sugarcane aphids. The study was done in a laboratory by using field-sprayed sorghum substrate. Two insecticides, flupyradifurone (Sivanto™) and sulfoxaflor (Transform®) were used in combination with the release of predatory lady beetle adults and larvae onto sugarcane aphids and their efficacies were evaluated. Treatments were Sivanto™, Transform®, lady beetle adult, lady beetle larva, Sivanto™ + lady beetle adult, Transform® + adult, Sivanto™ + lady beetle larva, Transform® + larva, and nontreated check. One day after insecticide spray and release of sugarcane aphids and predators, all treatments killed significantly more (48-83%) sugarcane aphids than did the nontreated check. Three days after treatment, all treatments except Sivanto™ and larvae killed significantly more (41-79%) sugarcane aphids than did the nontreated check. Significantly more sugarcane aphids were killed with predators combined with Sivanto™ (82-91%) and Transform® (96-97%) than with Transform® (59%), Sivanto™ (49%), or larvae (46%) alone. Lady beetle adults killed significantly more sugarcane aphids than did larvae. Seven days after treatment, no significant difference in sugarcane aphid mortality was observed between Transform® and Sivanto™. Fourteen days after treatment, abundance of sugarcane aphids increased in Sivanto™ treatments but no significant differences were found in sugarcane aphid mortality between nontreated check and Sivanto™ treatments. Sivanto™ and Transform® were similar, except Transform® displayed slightly longer residual activity in suppressing sugarcane aphids than did Sivanto™. Overall, a combination of lady beetle larva or adult with Transform® or Sivanto™ suppressed sugarcane aphids better than did Sivanto™ or Transform® alone. Sivanto™ and Transform® had no significant negative impact on predatory lady beetles.