Ayman M. Mostafa and Peter Ellsworth
University of Arizona, College of Agriculture and Life Sciences, Cooperative Extension
Over the last two weeks the UA Cooperative Extension IPM team received reports from pest control advisors of an aphid heavily infesting sorghum in many fields. The UA members of the Arizona Pest Management Center collected and field identified several samples from the Maricopa / Stanfield areas. The identification by Gene Hall UA Insect Diagnostician confirmed this invader as sugarcane aphid, Melanaphis sacchari. This is a new pest report for our state.
External identification characteristics of sugarcane aphid.
The infestation in many fields was overwhelming with the plants completely covered in stickiness from the honeydew excreted by the aphids.
Given this heavy infestation, it is likely this aphid has been in the state for longer than just this year, although reports extended only as far west as eastern New Mexico last year. The sugarcane aphid is distributed over the South, Texas and New Mexico; where it is one of the most important insect pests of grain and forage sorghum. Until recently the sugarcane aphid fed only on sugarcane in the US, but in 2013 it was found feeding on sorghum in southeast Texas near the border with Louisiana. This sorghum-feeding sugarcane aphid biotype spread over north Texas, southern Oklahoma, Louisiana, and Mississippi. Sugarcane aphids survived the 2013 winter in south Texas and spread throughout much of Texas and 12 other southern states during the spring and summer of 2014. In 2015, the sugarcane aphid spread through Texas into Oklahoma and Kansas, eventually infesting 17 states. This area encompasses 90 percent of the US sorghum acreage (Click here for 2015 distribution of sugarcane aphid). Giving the severity of this infestation and the rapid distribution of sugarcane aphid in Texas, this could become a serious impediment to sorghum production in Arizona with serious consequences on forage and dairy industries in the state. Giving the challenges facing forage crops, like alfalfa and now sorghum, in the last few years, it is important to bring different interested parties in the forage and dairy industry together for discussion.
Click here for more information from Texas A&M Agrilife Extension and Research about identification biology, damage, sampling and management.