Combining host plant resistance and foliar insecticide application to manage Melanaphis sacchari (Hemiptera: Aphididae) in grain sorghum

Authors: LAHIRI, SRIYANKA - University Of Georgia; Ni, Xinzhi; BUNTIN, G. DAVID - University Of Georgia; PUNNURI, SOMASHEKHAR - Fort Valley State University; JACOBSON, ALANA - Auburn University; REAY-JONES, FRANCIS - Clemson University; TOEWS, MICHAEL - University Of Georgia

Submitted to: International Journal of Pest Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/19/2019
Publication Date: 10/31/2019
Citation: Lahiri, S., Ni, X., Buntin, G., Punnuri, S., Jacobson, A., Reay-Jones, F.P., Toews, M.D. 2019. Combining host plant resistance and foliar insecticide application to manage Melanaphis sacchari (Hemiptera: Aphididae) in grain sorghum. International Journal of Pest Management. 67(1):10-19. https://doi.org/10.1080/09670874.2019.1660830.
DOI: https://doi.org/10.1080/09670874.2019.1660830

Interpretive Summary: The sugarcane aphid is an economically important piercing-sucking pest of grain sorghum occurring in over 30 countries from Asia, Africa, Australia, Central and South America for decades. In North America, the sugarcane aphid was previously reported only as a pest of sugarcane before 2013. However, a new strain of sugarcane aphid with preference for sorghum was recorded in Texas in 2013, which has since spread across 19 states in the southern U.S. This current invasive sugarcane aphid outbreak on sorghum cause significant economic losses to sorghum producers. Aphid resistant cultivars have proven to be an effective and economic pest management strategy. Because of explosive nature of the aphid infestation, and limited choices of insecticides available, the efficacy of both technologies (insecticides and aphid resistant varieties) for integrated aphid management was assessed across a variety of geographical locations within its invasive range. Thus, in 2017, five commercial grain sorghum varieties across five geographical locations in the southeastern U.S. states were evaluated for aphid damage and yield loss. The best grain sorghum hybrids with sugarcane aphid resistance were ‘DKS48-07’ and ‘DKS37-07’ across study locations. The most resistant variety, ‘DKS48-07’, required no foliar insecticide. Conversely, the most susceptible hybrids were ‘KS585’ and ‘DKS53-53’. In 2017, a single foliar application of insecticide Sivanto® immediately suppressed aphid populations and no further treatments were required.

Technical Abstract: Sugarcane aphid, Melanaphis sacchari (Zehtner), recently emerged as a severe economic pest of sorghum in the US. This insect was first discovered in the US feeding on grain sorghum in Texas in 2013 and then rapidly spread across 19 additional states. In order to develop management practices to prevent yield loss, the objective of this study was to assess the value of host plant resistance and foliar applications of insecticide in five commercially available grain sorghum hybrids, across five locations in the southeastern US. Field experiments were conducted in 2017 in Tift, Peach, and Pike Counties in Georgia; Barbour County in Alabama; and Darlington County in South Carolina. Foliar flupyradifurone applications were initiated at the action threshold of 50 aphids per leaf for each hybrid. Grain sorghum hybrids ‘DKS48-07’ and ‘DKS37-07’ showed resistance to M. sacchari across study locations. The most resistant variety, ‘DKS48-07’, required no foliar insecticide. Conversely, hybrids ‘KS585’ and ‘DKS53-53’ were highly susceptible. A single foliar application of flupyradifurone immediately suppressed M. sacchari populations and no further treatments were required.