Institute of Food and Agricultural Sciences
Hendry County Horticulture News
Lawn Pests Are Common in Florida
Several insect pests are common in Florida lawns. Southern chinch bugs suck plant juices. Mole crickets, and white grubs live in the soil and damage the grass roots. Other pests, including sod webworms, and armyworms, eat the grass leaves. Additional insects and related pests such as fleas, millipedes, chiggers, sowbugs, and snails do not damage the lawn but may become nuisances by biting people or crawling into houses, garages and swimming pools.
Studies have demonstrated that the need for pesticide applications to control chinch bugs and other insects can be drastically reduced by following certain management practices. Inspect the lawn weekly during the spring, summer, and fall months and biweekly during the winter months to determine if damage is beginning to occur and if insects are the problem.
Cultural practices can influence the susceptibility of lawn grasses to chinch bugs and turf caterpillars. Rapid succulent growth, resulting from frequent or high applications of water-soluble inorganic nitrogen fertilizers substantially increases the chances of insect attack. Contact the Hendry County Cooperative Extension office for fertilizer recommendations. Improper mowing and excessive watering and fertilizing can cause lawns to develop a thick, spongy mat of thatch. This is an excellent habitat for chinch bugs and turf caterpillars, and chemically ties up insecticides, reducing their effectiveness.
Proper mowing practices can make the grass more tolerant to pests and greatly improve the appearance of a lawn. The best recommendation on mowing is to mow often enough so that no more than one-third of the leaf blade is removed at each mowing. Insects are only a few of the many causes of yellowish or brownish areas in grass. Disease, nematodes, dry weather, and nutritional disorders are sometimes responsible for such injury. It is important to be sure of the cause so the proper treatment can be applied to correct the trouble without the needless use of pesticides and damage to the grass.
An effective way to survey for chinch bugs, lawn caterpillars, mole crickets and beneficial insects is by the use of a soap mixture applied with a 2-gallon sprinkling can. Mix 1½ fluid ounces of dishwashing detergent in a 2-gallon sprinkling can full of water, and drench 4 square feet with this solution. Observe the area for about 2 minutes. If pests are present, they will come to the grass surface and can be detected
Several species of mole crickets are prevalent in Florida. They have become a serious statewide turf pest in recent years. Mole crickets damage turfgrass in several ways. They tunnel through the soil near the surface and this tunneling action loosens the soil so that the grass is often uprooted and dies due to the drying out of the root system. They also feed on grass roots, causing thinning of the turf, eventually resulting in bare soil.
The southern chinch bug is the most important insect pest of St. Augustinegrass in Florida. Adults are about 1/5 inch long, and black, with white patches on the wings. Chinch bugs are seriously damaging only to St. Augustinegrass but will feed on other grass species. When chinch bugs are present in sufficient numbers they cause yellow or brown areas in lawns. The St. Augustinegrass varieties Floratam, Floralawn, and Floratine provide various degrees of resistance to chinch bug feeding
Several kinds of caterpillars, the immature or larval stage of moths, including sod webworms, armyworms, cutworms and grass loopers may cause damage to all turfgrasses. Bermudagrass is their favorite grass while bahiagrass is the least desirable.
White grubs can damage grass. These pests are the larval stage of beetles such as June beetles and masked chafers. White grubs larvae have three pairs of small legs near the head. They are white, with brown heads and a dark area at the rear of the abdomen. They rest in a C-shaped position. Grubs damage the grass by feeding on the roots.
Several predatory and parasitic insects attack lawn pests. The most prominent predator of chinch bugs is the big-eyed bug. One of the earwigs is a very good predator of both chinch bugs as well as several other turfgrass insects. It is known to eat as many as 50 adult chinch bugs in one night. Spiders and ground beetles are efficient predators of several harmful lawn insects and are considered extremely beneficial. Certain wasps are also a very common parasites of the lawn caterpillars. Big-eyed bugs are about the same size as chinch bugs and are often confused with them. Beneficial insects are often misidentified as being harmful and a pesticide is applied when it is not needed.
Apply insecticides properly. Read and understand all directions on the container label regarding dosage rates, application information, and precautions. To help prevent environmental contamination and the reduction of beneficial insects, spot treatments can be applied when infestations are first noticed and the damaged area is small. Treat the off-color area and about a 10-foot buffer area surrounding it. If damage is widespread over the yard or if many infested areas are detected, the entire yard should be treated. Inspect the area two to three times at biweekly intervals to determine if infestation is under control. Careful observation coupled with an understanding of your lawn pests will go a long way in helping you have a better lawn. Good luck and good gardening.
Gene McAvoy is the horticulture agent with the Hendry County Extension Service. Direct your horticulture questions to PO Box 68, LaBelle, FL 33975, e-mail - firstname.lastname@example.org or phone 863-674-4092 or 863-983-1598. You are also welcome to visit the Hendry County Extension Office at 225 Pratt Blvd., LaBelle. Office hours are from 8:00 - 5:00.
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