South Georgia Crop News

Crop News Covering Crisp, Turner, Worth, and Wilcox Counties

Bermudagrass Stem Maggot

The Bermuda grass stem maggot is a rising pest in some of our South Georgia hayfields.  Damage from BSM is a bronzing of the Bermudagrass, generating damage similar to that of severe drought or frost damaged Bermudagrass. The bronzing is the result of chlorosis and necrosis in the top two to three leaves of the plant. The damaged leaves could easily be pulled from the sheath and the end, inside the sheath either showed evidence of insect damage or obvious decay. This damage was clearly not that of abiotic stress but rather a consequence of larval feeding.

So the question arises as to what we should do about it. The answer to that question is all contingent upon the timing; if the Bermuda grass is 6-8 inches tall when infestation is observed, then harvesting the grass and following it with a chemical application would be the way to go. If BSM are observed while the grass is short 1-3 inches then chemical application prior to harvesting would be effective allowing the insecticide to cover the entire surface area.

Chemical suppression technique:

  • 1st application: 7-10 days after harvesting hay
  • 2nd application: repeat 7-10 days later or (14 to 20d after cutting)

Growers should apply a labeled rate of an insecticide.  Examples include: pyrethroids such as Baythroid, Karate, Mustang Max, and Tracer.