Sugarcane aphid (SCA) infestations have been documented in sorghum fields in 5 Virginia counties (Suffolk, Southampton, Surry, Sussex, and Isle of Wight—see infestation map, below). The area of the infestation likely includes more counties, but this is just a guess. Fortunately we are late into the season and many fields have either been harvested or desiccated in preparation for harvest. We maintain that there are fields still at some risk—those that will not be harvested for several weeks, especially any late planted fields. We are not concerned about loss caused by direct feeding, but the build-up of honey dew and sooty mold on leaves and heads. SCA infestations begin on lower leaves and these are not as important at this point in the season and pose less risk if they get covered with sooty mold. But if infestations move up the plant to upper leaves and heads, problems with combining could occur.
If you have been keeping up with pervious advisories you know that the insecticides most commonly recommended for control of SCA are Sivanto (Bayer CropScience) and Transform (Dow). But only Sivanto is currently labeled. We attempted to secure a Section 18 Emergence Exemption for the use of Transform but hit a snag. Following are the recent comments from the EPA reviewer regarding the status of our request. “Due to the federal court’s recent (September 10th) decision vacating EPA’s unconditional registration of sulfoxaflor the authorization of our request is on hold and remains pending. The EPA is reviewing the court’s opinion to determine their next steps”. So, right now it does not sound promising for the Section 18 use of Transform in Virginia before the end of the use season. It definitely means we don’t have use of the product for the recently found infestations. So Sivanto would be the best alternative, but hopefully, fields will not have to be treated.