Outbreak of sorghum/sugarcane aphid on sorghum: First detections, distribution, and notes on management

Authors: BREWER, MICHAEL - Texas A&M Agrilife; WAY, MO - Texas A&M Agrilife; Armstrong, John; BILES, STEPHEN - Texas Agrilife Extension; SEKULA, DANIELLE - Texas Agrilife Extension; SWART, JAMES - Texas Agrilife Extension; CRUMLEY, CLYDE - Texas Agrilife Extension; KNUTSON, ALLEN - Texas Agrilife Extension; VILLANUEVA, RAUL - Texas Agrilife Extension; PARKER, ROY - Texas Agrilife Extension; ODVODY, GARY - Texas A&M Agrilife; RAGSDALE, DAVID - Texas A&M University

Submitted to: Texas Plant Protection Conference Program
Publication Type: Proceedings
Publication Acceptance Date: 12/11/2013
Publication Date: 12/11/2013
Citation: Brewer, M.J., Way, M.O., Armstrong, J.S., Biles, S.P., Sekula, D., Swart, J.S., Crumley, C.R., Knutson, A.E., Villanueva, R.T., Parker, R.D., Odvody, G.N., Ragsdale, D.W. 2013. Outbreak of sorghum/sugarcane aphid on sorghum: First detections, distribution, and notes on management. 25th Texas Plant Protection Conference Program, December 11-12, 2013, Bryan, TX. 1 p.

Interpretive Summary:

Technical Abstract: An outbreak of an invasive aphid was discovered damaging grain sorghum in Texas and neighboring states in 2013. It may be a new variant of sugarcane aphid, Melanaphis sacchari, that has a high preference for sorghum, or a very closely related species (M. sorghi). We designate it sorghum/sugarcane aphid here (SA). The 2013 outbreak caused severe damage, with producers and crop consultants estimating 25-50% yield loss and total yield loss in some unprotected fields. Infestations were initially observed after sorghum heads were developing, but likely began infesting the crop earlier. Infestations detected were very heavy, often with hundreds of SA per leaf. Leaves became sticky and shiny from honeydew and coated with sooty mold fungus (grows on honeydew) which hampered harvesting operations. Heavy SA populations and honeydew/sooty mold fields were observed in the lower Rio Grande Valley, the Gulf Coast, central Texas Blacklands, and northern counties bordering the Red River, as well as in southern Oklahoma along the Red River and from southwest to northeast Louisiana. Fall populations on remnant sorghum of harvested fields and Johnson grass have been detected in many of these counties, positioning the aphid for possible outbreaks next year. Early insecticide trials have identified early management options, and natural enemies have also been observed feeding on SA.