According to the Florida Lawn Handbook, several insects and insect relatives live in Florida lawns, but not all of them hurt the grass. Many are harmless, some are beneficial, and some are pests. Only a few cause significant damage and need immediate control. For example, chinch bugs, spittlebugs, and grass scales live on the plant foliage and suck plant juices. Other pests, including sod webworms, grass loopers, and armyworms, eat the grass leaves. Mole crickets, white grubs, and billbugs live in the soil and primarily damage grass roots, in addition to creating tunnels and/or mounds. Other insects and related pests (e.g., fleas, millipedes, chiggers, sowbugs, and snails) are nuisances because they may bite people or pets or invade houses, garages, or swimming pools.

Preventive or by-the-calendar treatments (pesticide applications made every 4 to 8 weeks) may kill many beneficial organisms and contribute to a persistent pest problem. Thus, pesticides should be applied only when damage is apparent. Research has demonstrated that the need for pesticide applications to control insect outbreaks can be drastically reduced by following these management practices.

Monitoring

  Early detection of insects is vital to any management program. Check the lawn for pest activity every 14 days in the winter and every 7 to 10 days in the spring, summer, and fall, especially in “hot spots” where damage tends to reoccur.
Factors other than insect outbreaks may also result in thin or brown grass, including diseases, nematodes, drought, and nutritional disorders. Correct identification of the problem can save money, prevent excessive damage to the grass and unnecessary pesticide applications.

Nutrition

Over-fertilization generally increases plant susceptibility to sap-feeding insects. Some insects tend to feed more on actively-growing plant parts, rather than the older, slower-growing ones. Incidence of damage from these pests can be greatly reduced with applications of minimum amounts of slow-release nitrogen fertilizers in combination with other macro-and micronutrients. Contact your local county Cooperative Extension office for fertility recommendations and sources of slow-release nitrogen fertilizer for each of the turfgrass species in your particular area of the state.

Mowing

Improper mowing, coupled with over-watering and improper fertilization can cause lawn grasses to develop a thick, spongy mat of live, dead, and dying shoots, stems and roots which accumulate in a layer above the soil surface. This spongy mat, called thatch, is an excellent habitat for chinch bugs and turf caterpillars, and chemically ties up insecticides, therefore reducing their effectiveness. When a serious thatch problem exists, it may be necessary to remove the thatch mechanically (vertical mowing, power raking, etc.). Proper mowing practices can make grass more tolerant to pests and greatly improve the appearance of a lawn. The best recommendation is to mow often enough so that no more than one-third of the leaf blade is removed at each mowing.

For more information on lawn insects, including identification and control of specific insects, visit 
http://edis.ifas.ufl.edu/lh034