Parasitization of the sugarcane aphid, Melanaphis sacchari, by commercially available aphid parasitoids

Abstract

Identification of natural enemies of novel pests is important for the development of effective integrated pest management. Commercially available parasitoids used for control of arthropod pests have potential for enhancing biological control of invasive pests. The sugarcane aphid, Melanaphis sacchari (Hemiptera: Aphididae), is a new pest on sweet sorghum, Sorghum bicolor, in the USA. Surveys of M. sacchari have not detected any parasitoids in central Kentucky. In North America, Aphelinus abdominalis (Hymenoptera: Aphelinidae), Aphidius ervi (Hymenoptera: Braconidae), Aphidius colemani, and Aphidius matricariae are sold for aphid management. This study’s objective was to determine the host acceptance and suitability of M. sacchari for these parasitoid species. Host acceptance was assessed by counting attacks and oviposition strikes by parasitoids on M. sacchari. All parasitoid species accepted M. sacchari as a host in the parental generation (purchased adults) and the F1 generation (reared from M. sacchari). Host suitability was evaluated by transferring M. sacchari from host acceptance trials to caged sweet sorghum plants. Cages were monitored for aphid mummies and emerged adult parasitoids. Parental A. colemani produced the most mummies and adult parasitoids and reduced final M. sacchari numbers by 75%. A. ervi had a similar impact on M. sacchari populations but produced fewer mummies and adults. A. matricariae and A. abdominalis did not reduce M. sacchari populations. F1 parasitoids produced few adults and did not reduce M. sacchari populations. A. colemani demonstrated potential for field releases with the ability to use M. sacchari as a host and reduce aphid population growth.