Scout your lawn for pests of August

It seems that every season of the year has an active pest problem. There is not a season that I can think of that doesn't have a pest that attacks our plants, pets, homes or us. Right now, chinch bugs are attacking St. Augustine grass. In the spring and fall, large patch attacks our grasses. It is a never-ending cycle of pests.

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With that said, we need to get ready for the next set of pests that will be showing up in a couple of weeks. Every year around the last week of August and the first couple of weeks in September, we have problems with fall army worms and red-headed Azalea caterpillars.

Fall army worms (Spodoptera frugiperda) are a tropical species that survives in warmer climates along the gulf coast or South Florida. They start infesting plants in South Florida in February and March and move north as the weather warms. They tend to show up in our area around the last week of August or first week of September, and they can last until frost.

We have some army worms every year, but about once every three years we have a major outbreak. Last year, we didn't have a major outbreak. In our area, fall army worms are major pests to Bermuda grass, millet and fall vegetables. I get the most calls because of damage done to home lawns, hay fields and pastures.

Army worms get their name from the large number of caterpillars that can be in an area. The adult stage is a moth. The female moth will lay about 400 eggs. These eggs are laid at night on plants, flagpoles, stones or anything that is close to the food source. When the caterpillars are small, they will chew on the underside of the leaf and usually doesn't consume the whole leaf. As the caterpillar gets larger, they consume the entire leaf or plant.

When the food source becomes scarce, the entire population of caterpillars will move to a new food source. I have seen a 2,000-square-foot lawn have tens of thousands of army worms in the area. This many caterpillars can eat a lawn this size overnight. The time it takes for the caterpillar to hatch from the egg until is starts to pupate is two to three weeks.

Not every caterpillar that you find this time of year is a fall army worm. The way that you can identify army worms is they have an upside down Y on their heads. If you have a spot in your lawn that is missing the foliage, start looking for army worms. In bright sunlight, army worms will be found near the soil surface.

You can use a soap flush to help find the caterpillars. You will need three to five gallons of water with 2 tablespoons of dishwashing liquid. Fill the container with water then add the soap. You don't want a lot of suds because this will hide the caterpillars. Pour this over a 3-foot-by-3-foot area. If there are caterpillars or other insects in the turfgrass, they will emerge.

If you have armyworms, you can treat them with Bacillus thuringiensis (Bt, Dipel), carbaryl (Sevin) or various pyrethroids found in the garden centers. We can have up to two generations of armyworms in the fall, so you need to watch for them until frost.

The other pest that we encounter is the red-headed azalea caterpillar. This is a serious defoliator of azaleas. The azaleas look great one day and the next they have no foliage. These caterpillars are brightly colored. They have yellow and black bodies with red legs and head. When you touch these caterpillars, they arch backwards forming a C. The female moth, as in the case of army worms, lays a large number of eggs in a cluster, so you have a large number of caterpillars on one shrub.

You can control these caterpillars with the same products that you used to control army worms. Also, you can use acephate (orthene) to control them. You need to make sure that the temperature is in the 80s or lower before using acephate.

The best thing that you can do for now is to scout your plants and lawn for these pests. Scouting is done by looking at your plants or using the soap flush in your lawn to find small caterpillars. When you find the small caterpillars, you then can treat. The smaller the caterpillar, the easier it is to control. If you find some caterpillars and need help identifying them, I will be glad to help.

Reach Columbia County Extension agent Charles Phillips at (706) 868-3413 or charlesp@uga.edu. or the Extension at www.ugaextension.com/columbia.