US-EPA Grants Section 18 Emergency Exemption Label for Use of Transform™ WG for Control of Sugarcane Aphid on Grain Sorghum in Kentucky.

Doug Johnson, Extension Entomologist, University of Kentucky

The United States Environmental Protection Agency (US-EPA) has granted the use of Transform™ WG for control of the sugarcane aphid, (Melanaphis saccahri) on sorghum.

Update & Correction Concerning Collection of Sugarcane Aphid in Kentucky Grain Sorghum

Doug Johnson, Extension Entomologist, University of Kentucky.

This note is provided for clarification of where in Kentucky Sugarcane aphid has been collected and identified. The first two collections were reported as Fulton and Graves counties. This was incorrect

Sugarcane Aphid Collected in Kentucky

Doug Johnson, Extension Entomologist, University of Kentucky

Sugarcane aphid (SCA) has been collected in two western Kentucky (KY) Counties. County Extension Agents Ben Rudy in Fulton Co. and Trent Murdock in Graves Co. have collected SCA from grain and sweet sorghum respectively. Identity was confirmed by Dr. Lee Townsend, Extension Entomologist, with the University of Kentucky (UK) in Lexington. Thus far, only the two infestations have been reported. The infestation in Fulton Co. is below treatment threshold, but the infestation in Graves Co. is much larger. Regardless of size, this does confirm that this new sorghum pest which likely migrates in from the Deep South can reach Kentucky during, if late, in the production season. Sugarcane aphid is a threat to all forms of sorghum (grain, forage, sweet) and will infest many other grasses including Johnson grass, which can act as a host for reproduction and a source of infestation.

Sugarcane Aphid Reported in Tennessee

Doug Johnson, Extension Entomologist, University of Kentucky @DrDougStinkBugs

Dr.Scott Stewart (@BugStewart) has tweeted the first discovery of sugarcane aphid (SCA) in Tennessee (07/07/15) at the AgriCenter in Memphis. The aphids were found and photographed by Drew Ellis. Numbers are low, but this does indicate that the pest is moving up the Mississippi River valley.

Several of our colleagues to the mid-south have commented on the large number of  lady beetles  & larvae that are feeding on these aphids, helping to keep the pest in check. A single insecticide application will stop all that help. Do not apply until absolutely necessary!

Kentucky producers in counties along the Mississippi River and / or counties contiguous with western Tennessee counties are most likely to see this pest.

SCA was not reported in Kentucky in 2014 but was collected in western Tennessee counties and in counties in the Missouri boot-heel. It is not a foregone conclusion that SCA will reach Kentucky, but it is an important enough pest to keep on your watch list.

Grain Sorghum producers / consultants / scouts, that are Twitter followers are encouraged to follow Dr. Scott Stewart, Univ TN, (@BugStewart) along with Dr. Gus Lorenz, Univ. AR , (@guslor77) and Dr. Angus Catchot, MS. St. Univ. (@acatchot). They will be working to manage this problem in their states before the pest gets to Kentucky; if it gets to Kentucky.

KNOWLEDGE IS MONEY!

New Aphid Pest on Grain Sorghum – Sugarcane Aphid

Doug Johnson, Extension Entomologist, University of Kentucky

Figure 1. Sugarcane aphid on
sweet sorghum; Shelby Co. TN
2014. Univ. TN.

Over the past two growing seasons a difficult new insect pest of grain sorghum has been found across the mid-south. This new pest is an aphid called the sugarcane aphid, Melanaphis sacchari. Be sure not to confuse this with the yellow sugarcane aphid, Sipha flava, which has been around the lower Mississippi river valley for several years. These are two completely different insects. Before we go any further, it is important that you understand that at present, NEITHER of these aphids have been found in Kentucky. My concern is one of preparation, as both of these aphids are found in western Tennessee and southeastern Missouri.

Watch for worms in grain sorghum heads

Doug Johnson, Extension Entomologist

Fig. 1. Corn earworm on Corn

Fig. 2. Sorghum webworm
 on sorghum

It is about the time of year for problems with corn earworm (Fig.1.) to begin in grain sorghum. Though I have not seen or heard of any local problems my colleague in VA, Dr. Ames Herbert, is beginning to see some problems. In Kentucky we generally see these problems in the area west of the Pennyrile Parkway and more importantly in LATE planted fields. You are also likely to see a mixture of worm species including the sorghum webworm (Fig. 2.)