: NEW EXOTIC INVASIVE FLY FOUND DAMAGING BERMUDAGRASS FORAGE CROPS IN GEORGIA

Summary

A new exotic invasive fly, Atherigona reversura, also known as the bermudagrass stem maggot, was discovered in Georgia damaging bermudagrass pasture and hay fields. This is the first record of this species in North America and may represent a new serious pest of bermudagrass forage crops and turf.

Situation

Bermudagrass is the most widely grown grass for forage, pasture and hay production in the coastal plain region of the southeastern U.S. Bermudagrass also is widely used as a turf grass in the southern U.S. and around the world and represents the bulk of sod grown in Georgia, a crop worth an estimated $116 million in 2009. In July of 2010, extensive damage to bermudagrass pastures was reported by county agents in southern Georgia. The damage consisted of the death of top leaves and growing point of infested stems in a manner that had not been observed before. Many fields were heavily infested and gave the appearance of frost or cold damage. The damage was quickly associated with very small stem-boring maggots.

Response

Maggots are almost always the larval stages of various species of flies. Infested plants were collected and held in the laboratory to rear adult flies for identification. Infested pastures also were sampled to collect adult files. After several weeks a small gray and brown fly was recovered. It did not correspond with any previously reported pest of bermudagrass in Georgia. Adult flies were submitted to the University of Georgia Museum of Natural History for species identification, where Dr. Cecil Smith identified the flies as members of the family Muscidae but could not make a definitive species identification. Specimens were sent for identification to the Smithsonian Institution, and ultimately to Dr. A. C. Pont at the British Museum, the leading world expert on muscid flies. : The flies were identified as Atherigona reversura. This species is native to Asia. Its presence in Georgia is the first record of this species in North America and represents a new exotic invasive species. The common name used in Asia is the bermudagrass stem maggot. Subsequent reports in August and September revealed that A. reversura now occurs throughout southern Georgia and also is present in northern Florida and parts of Alabama and South Carolina. Several on-farm trials with registered insecticides found that a single application only reduced infestations for short time. We also observed a noticeable difference in damage levels among bermudagrass varieties.

Impact

We are planning a series of laboratory and field research studies for next season to examine the biology and methods of control of this new pest of bermudagrass.

State Issue

Agricultural Profitability and Sustainability

Details

• Year: 2010
• Geographic Scope: Multi-State/Regional
• County: Tift
• Program Areas:
  • Agriculture & Natural Resources