1. Turfgrass Pest Management (Category 3A)

Pest Management Techniques

Chapter 3

2. After identifying a pest and understanding its biology and economic significance, you

are ready to develop a strategy for managing it. There are two types of pest management tactics: immediate, short-term suppression, and long-term maintenance of non-damaging pest levels. Most pest problems require the use of both types of tactics.

3. For example, Rhizoctonia brown patch attacks the new growth of grass plants. Rhizoctonia fungi can enter and infect only blades that are moist. Applying fungicide to protect susceptible turf from Rhizoctonia infection is a short-term suppression tactic that provides immediate, but temporary control. Without changing the environmental conditions to discourage moist conditions and limiting tender growth during infections periods, Rhizoctonia can be an on-going problem.
4. Lessen the humidity around turf susceptible to Rhizoctonia by removing sheltering plants, tree limbs, structures and clippings. Do not over water turf! Avoid high nitrogen fertilizer that produces succulent growth susceptible to Rhizoctonia.
5. The first step in discouraging turf pests is to assure the healt and vigor of the turf. Healthy turf is better able to combat pests and withstand pest injury. Matching the grass plant variety or species to site conditions is essential to turf vigor. Carefully consider site characteristics such as drainage and sun exposure when establishing new turf and use grasses that are tolerant to them. Improve growing conditions of established stands to favor grass development and deter pest establishment.
6. Basic maintenance practices such as mowing, fertilizing, and irrigation are important cultural activities. Turf managers also commonly incorporate cultural controls such as raking, thatch removal, aeration and topdressing to improve turf performance. Know how to properly implement these practices to benefit, rather than stress turf.
7. Many cultural controls used on turf limit disease inoculum and pest habitat. Diseases like leafspot live in, and form fruiting bodies on grass plants and debris. Collecting and disposing of inoculum-infested clippings reduces their spread. Other cultural practices for pest management include providing adequate but not excessive fertility, removing thatch (fusarium patch), improving air movement (powdery mildew), and avoiding heavy watering (summer patch).
8. Probably the most common cultural control for turf is mowing. Weeds are reduced in turf stands by an average of 90% when turf is mowed at its preferred height.
9. Mechanical and physical controls are tactics that physically separate the pest from the host plant. These tactics are easy to do and totally non-toxic.

• Hand removal: Larvae of sod webworm and cutworms, and chinch bugs can be removed when the insects are actively feeding by cutting at a low height and removing the clippings. Controlling slime mold is simply a matter of raking or mowing it out.
• Traps: Moles, skunks, and other animal pests can be removed by trapping. Note: the Michigan Department of Natural Resources requires a permit to trap wild animals. Mice, voles, rats, moles and chipmunks are exempt.
• Barriers: Underground barriers to keep tunneling animals out of valuable turf have been only somewhat successful.
• Repellents: Taste, odor, visual, hearing or vibration repellents are designed to frighten or annoy pests. As yet, repellents for vertebrate turf pests provide only limited protection. Over time, pests become used to the repellent and do not leave the area.

1. Biological controls limit pests with naturally-occurring and introduced parasites, predators and diseases of pests. Natural enemies abundant in turfgrass include species of fungi, parasitic wasps, ants, beetles, spiders, and nematodes.
2. People seldom appreciate th importance of natural enemies until the biological balance of the system is upset. Chinch bugs often become damaging after an insecticide application, because of the reduction in predators. One of which is the big-eyed but. Typical of insect predators, big-eyed bugs are more sensitive to insecticides than turf pests. When monitoring turf, do no confuse chinch bugs (left) with their big-eyed predators (right).
3. Protect established populations of beneficials by avoiding unnecessary environmental disturbances, especially pesticide applications. Remember, only 10% of homeowner lawns develop insect infestations requiring insecticide. When pesticides are necessary, target the application and avoid broad-spectrum and highly toxic products.

Because natural enemies depend directly upon the availability of pest to survive. Do no attempt to eradicate pests. Use only the amount of pesticide necessary to prevent unacceptable injury to turf and bring the pest population below threshold level.

4. The United Sates government imports and studies natural enemies of pests. Researchers are currently exploring the use of weed-feeding insects and fungal diseases to suppress weeds. Since releasing exotic organisms can result in new pest problems, natural enemy release is restricted to government personnel. There are several pest pathogens, however, on the market as microbial insecticides.
5. The most commonly used microbial insecticide is Bacillus thuringiensis or Bt. This bacterial disease kills many insect larvae including armyworm, cutworm, sod webworm and other caterpillars. Microbial insecticides do no rapidly suppress high, damaging population of pests. However, when used properly, pathogens maintain low levels of pests with very little risk to the environment or nontarget organisms.

Milky spore disease, Bacillus popullae, attacks Japanese beetle, European chafer and other white grubs. There are several naturally occurring pathogens in the soil that help suppress pest species.