This article is meant to be used in conjunction with the article entitled Insects and Other Common Pests of Lawns. It is intended to supply information for the control of the more common pests found in lawns.

Pests of lawns fall into two categories--those that live in the soil, such as white grubs and ants, and those that live near or at the surface of the soil, such as chinch bugs, sod webworms, cutworms, birds and skunks. The chemical control of lawn pests requires that the pesticide be applied where the pest will come into contact with it. Therefore, chemicals applied for the control of soil-inhibiting pests must be moved into the soil. This is accomplished with water. Chemicals applied against pests living at or near the surface of the soil must remain on the surface of the plant to be effective. Read and follow label instructions when using any pesticide.

White Grubs

White grubs can be controlled by treating the lawn with liquid or dry formulations of trichiorfon, imidacloprid, and halofenozide. Imidacloprid and halofenozide work best when applied from mid-June through July. Both products work best when applied as a preventative treatment. Applications should be applied before or during egg laying of the adult beetle. Trichiorfon insecticide works curatively. Applications of this product is made after eggs hatch, usually late July through September in the Northeast. Curative products work best when applied early when grubs are still small (first to second larval stage).

Milky spore disease, caused by the bacteria Bacillus popilliae, is used to control Japanese beetles and some strains of European chafer grubs. The success of this disease depends on a number of factors, especially soils temperature and moisture. The disease-causing bacteria develop best at soil temperatures between 60 and 97 F. Where soil temperatures remain above 70 F for several months, the disease can build up in a year. Unfortunately, Connecticut does not fall into this category, and it may take three or more years for a build-up. Once established, the milky spore bacteria will spread to adjoining untreated areas. Studies in Connecticut suggest that milky spore disease is not as virulent as it once was, that grubs have become resistant to it or that different species of grubs are present that are resistant to milky spore disease. It is known that the Asiatic garden beetle is present in increasing numbers and that it is not affected by milky spore disease.

Milky spore disease powder is sold as powder or granules. Apply as directed on the label. Do not use on areas treated with an insecticide. Grubs must be present to maintain and spread the disease. It has no effect on non target organisms such as earthworms, caterpillars or warm-blooded animals.

Chinch Bugs Apply either carbaryl, chlorpyrifos, diazinon, acephate, or pyrellin, a mixture of the botanical insecticides rotenone and pyrethrin. Do not cut the grass for one to three days after treatment. A repeat application may be necessary in three weeks.

Sod Webworms Sod webworms can be controlled by the insecticides acephate, carbaryl, chlorpyrifos, diazinon, or trichlorfon. The bacteria Bacillus thuringiensis var. Kurstaki (B.t. var. Kurstaki) and parasitic nematodes are biological alternatives to chemical control of sod webworms.

Photos provided courtesy of University of Nebraska-Lincoln, Entomology Department

Ants

Apply carbaryl, chlorypyrifos, diatomaceous earth, or diazinon granule or wettable powder. In some areas it may be advisable to use baits. If baits are to be used, floor label instructions carefully. Keep all pesticides out of the reach of children.

Moles

Moles require a constant food supply and cannot live long when it is not available. Since white grubs are a main food source for moles, controlling the white grubs will reduce the moles' food supply. Earthworms are another major source of food for moles, but the beneficial effects of the worms may outweigh the harm committed by the moles.

Materials such as moth balls, rat poison and mole knots are not effective in controlling moles, and it is illegal to use the first two as a rodenticide. If a few moles persist after the grubs have been controlled, use traps to eliminate them completely. Properly set traps are the surest method of eliminating moles. To be effective, set traps in those runways that are used daily by the moles. You can locate active runways by rolling or tamping down runways in the early morning. Then set traps in those runways which have been raised again by the afternoon of the same day. Mole traps are available at hardware and garden supply stores.

Edmond Marrotte, Consumer Horticulturist, University of Connecticut
Updated 6/10/04 by Steven L. Rackliffe, Extension Instructor Turfgrass Science, University of Connecticut

This information was developed for conditions in the Northeast. Use in other geographical areas may be inappropriate.

The information in this material is for educational purposes. The recommendations contained are based on the best available knowledge at the time of printing. Any reference to commercial products, trade or brand names is for information only, and no endorsement or approval is intended. The Cooperative Extension system does not guarantee or warrant the standard of any product referenced or imply approval of the product to the exclusion of others which also may be available.All agrochemicals/pesticides listed are registered for suggested uses in accordance with federal and Connecticut state laws and regulations as of the date of printing. If the information does not agree with current labeling, follow the label instructions. The label is the law.Warning! Agrochemicals/pesticides are dangerous. Read and follow all instructions and safety precautions on labels. Carefully handle and store agrochemicals/pesticides in originally labeled containers immediately in a safe manner and place. Contact the Connecticut Department of Environmental Protection for current regulations.The user of this information assumes all risks for personal injury or property damage.Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture. Kirklyn M. Kerr, Director, Cooperative Extension System, The University of Connecticut, Storrs. The Connecticut Cooperative Extension System offers its programs to persons regardless of race, color, national origin, sex, age or disability and is an equal opportunity employer.