Horticulture Hotline 07/13/21
By Bill Lamson-Scribner
Army worms, sod webworms, mosquitoes, gray leaf spot, chinch bugs, nutrient deficiencies, weeds, heat, vines, fire ants, lace bugs, rats, flies, fleas, termites and roaches seem to be dominating the questions at the counters at all three Possum’s. That Elsa brought us more than rain and wind!
Army worms will affect the aesthetic value of the green grass on athletic fields, golf courses, and home lawns, and the worms thin the canopy of the grass Prostrate growing weeds like spurge, lespedeza and Virginia Buttonweed seem to come in the fastest. I have seen or heard reports of these worms from Summerville to West Ashley to Isle of Palms.
The army worm female can lay over 1000 eggs. She usually lays them in groups of 50 to several 100. The eggs hatch in 2 to 10 days. The larva then eats your grass for 14 to 21 days before they return to the soil and pupate. New egg laying moths emerge in 10 – 14 days. With several hundred larvae eating your grass at once, you can imagine how quick army worms can ruin your grass.
Look for areas that appeared to have been mowed low and with a dull blade. You can see that the leaf blades have been chewed. Also thatch type debris will be churned up on the surface. Birds and low flying wasps are also predators of army worms.
Since army worms are in direct contact with the ground, they are very easy to control. Bug Blaster, Bifen, Sevin, Cyonara and Acephate will all put a hurting on army worms. Thuricide (Bt), EcoVia EC and Spinosad are organic products that will also work well if you get them while the worms are small. Since the population of worms is so high and hit so hard, keep your eye out for a second hatching. 08-00-08 with Acelepryn is a long residual product with a little fertilizer to help the grass recover quickly.
For those of you with St. Augustine, zoysia, bermuda, bahia or centipede, keep your eye out for the sod web worm. Watch for moths in your yard around dusk. If you begin to see a moth that gets out of the grass, flies for 6-10 feet then lands again (like a bobwhite quail for you bird hunters) you may want to consider using one of the above-mentioned products. Usually sod web worms would not come out until September / October; however, with the crazy weather we are having, scouting for them could not hurt.
We just had a wind event that came up from the south. The moths of these worms will often catch a ride on wind currents from areas that they are active year-round. Watering first to bring the worms to the surface and applying products in the evening when the larvae are about to feed, will often help your success depending on the product.
If your yard has thatch, drainage, or compaction issues, now is a great time to aerate your lawn (and beds where possible) before you apply your fall preemerge. Aeration is a great cultural practice, which will among other things help your roots grow throughout the winter giving you a head start for the spring.
The “nasty rascal the chinch bug” is still sucking the life out of many lawns. Gray leaf spot is still alive and doing well. With the rain, fire ants are mounding up everywhere – be careful where you step! Mosquitoes are out and biting especially in the evening. Flies are causing many backyard grill master’s grief.
Always read, understand and follow product label. The product label is a Federal Law.
