Fall armyworms have invaded Houston County and the surrounding counties. Our calls have come from hay producers seeing them in their fields, but if they are in the hay fields they will soon find their way into your yard.
The damage that they cause to turf is mostly aesthetic, but new sprigged sod can be severely damaged or killed.
There are other caterpillars that can cause damage to turf, but in late summer the culprit is usually the fall armyworm. Fall armyworms migrate north every year from their southern overwintering areas.
Hot, dry weather can intensify fall armyworm problem when egg-laying adults concentrate their eggs in irrigated turf. Adult armyworm moths are active at night. Females lay eggs in masses containing 50 to several hundred. Egg masses on structures around turf can be the first indicator of an infestation.
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Eggs hatch in a few days, and the young larvae begin feeding on leaf tissue. Damage from small larvae may at first look like skeletonizing, but as they grow the entire leaf is consumed.
Small larvae are easier to control than the larger ones. After the larvae are full grown, usually between 2-3 weeks after hatching, they will pupate in the upper soil/thatch layer. At this point they will not be susceptible to insecticides. Moths will emerge 10-14 days later.
Pouring soapy water on the grass ( 1/2 oz of dish soap per gallon of water) is one way to determine if fall armyworms are present. The soapy water will bring them to the top of the turf. Greenish-black fecal pellets are also visible in heavy infestations. Other indicators of the presence of fall armyworms are paper wasp and brides feeding in your yard.
In addition to birds and paper wasp, there are a number of insects that feed on fall armyworms. Parasitic wasp can also cause heavy damage to the fall armyworm population. These natural enemies can be conserved by spot instead of blanket spraying of insecticides and properly timing control efforts.
Controlling fall armyworms and other caterpillars is relatively simple once they are identified. Various pyrethroids, trichlorfon, carbaryl or bacillus thuringiensis are recommended treatments. Most or all of these can be found at any “big box store.” Fall armyworms are most active at night, so pesticide applications should be made late in the evening for best results.
Cutting the grass before applying the insecticide may improve control, but do not cut the grass 1-3 days after application. It is not necessary to water after application, but an application rate of 20-25 gallons of solution per is a minimum to ensure good coverage. Always read and follow labeling instructions.
For more information on any program area, contact Houston County Extension at 478-987-2028 or drop by our office in the old courthouse, downtown Perry, 801 Main St. Office hours are 8 a.m.-5 p.m., Monday through Friday. Visit our website at www.caes.uga.edu/extension/houston/ for more news about your local extension office.
*Check out my blog at http://blog.extension.uga.edu/houston/
Dates to Remember
Aug. 12: CAFO/NPDES permitting meeting, Georgia Farm Bureau Building, Macon, 2-3 p.m.
Aug. 20: CAFO/NPDES permitting meeting, UGA Livestock Arena, Athens, 10-11:30 a.m .
Aug. 28: CAFO/NPDES permitting meeting, UGA Tifton Campus, Tifton. 10:30 a.m.–12 p.m.
Sept. 11: Fall planting class, Houston County Extension Office, Perry. 6:30-8:30 p.m. Cost is $10, Register by Sept. 4
Sept. 18-20: MGCG Fall Plant Sale, State Farmers Market, Macon.