As Dr. Ames Herbert mentions in his July 25, 2016 blog, we are seeing a mixture of aphids in Virginia sorghum fields this season, but we should guide control decisions based on white sugarcane aphid (Melanaphis sacchari) numbers and product recommendations (I recommend re-reading Dr. Herbert’s advisory and viewing the aphid images that he attached back on July 25).
As Dr. Mike Brewer of Texas A&M mentioned to us earlier this week, corn leaf aphids (Rhopalosiphum maidis) are rarely worth concern–they are just good food for beneficial natural enemies!
The Tidewater AREC Entomology crew, Virginia Cooperative Extension Agents, and other Virginia Tech faculty and staff (e.g., Dr. Joseph Oakes) have been hunting for white sugarcane aphid. We have confirmed it in Greensville (through ANR Agent Nikki Norton), Nottoway (through Jim Riddell, and ANR Agent Haley Norton), Southampton (via ANR Agent Livvy Preisser, and Mike Arrington at the Tidewater AREC), and Sussex (via Mike Arrington).
You may notice that last week I reported white sugarcane aphid in Dinwiddie–that has been removed for the time being, but ANR Agent Mike Parrish is following up on a lead as I am writing this report. In some locations, we have found yellow sugarcane aphid (Sipha flava) along with the white sugarcane aphid.
I have indicated on the attached map where these have been reported, and also where we have scouted sorghum, but have not found any sugarcane aphids (to date). Please keep up the scouting efforts in your sorghum fields!