A Guide to Integrated Pest Management

If skipper larvae are damaging turfgrass, dethatch the turfgrass to eliminate larval habitat. If monitoring indicates treatment is warranted, treatment choices include parasitic nematodes and Bacillus thuringiensis (Bt). photo: www.cirrusimage.com

Integrated Pest Management (IPM) is an effective and environmentally sensitive approach to pest management that relies on a combination of common-sense practices that can significantly reduce or eliminate the use of pesticides.

IPM is applicable to all types of turf and ornamentals. Reliance on knowledge, experience, observation, and integration of multiple techniques can reduce human and environmental exposure to hazardous chemicals, and potentially lower overall costs.

In 2005, the Asian Longhorn Beetle was found in a warehouse in Sacramento. The pest has the potential to destroy millions of acres of hardwood trees such as elm, maple, boxelder, birch, horse chestnut, poplar, willow, mimosa, and hackberry. Infestations in New York, Illinois, and New Jersey resulted in the removal of thousands of trees and cost state and federal governments in excess of $168 million. If you find these killers visit www.wripmc.org/alerts/, which can educate you on how to report and prevent Asian longhorned beetle infestations.

How IPM works

IPM is not a single pest control method but, rather, a series of pest management evaluations, decisions and controls. The practice is studied by entomologists, plant pathologists, nematologists, and weed scientists to further its use. The main focus is usually insect pests, but IPM also encompasses diseases and weeds as well. In practicing IPM, professionals who are aware of the potential for pest infestation must follow a multi-tiered approach. The steps include the following basic components:

If bermudagrass mite is infesting turfgrass, reducing nitrogen fertilization and close mowing or scalping with removal of clippings can slow down reproduction of, or physically remove, bermudagrass mites. To confirm presence of this mite, examine leaf sheaths of stunted plants with a 10X or 30X hand lens for mites and their eggs. If a treatment seems necessary, mow the turf closely and remove clippings first. In addition to physically removing most of the population, it may also displace remaining mites so that they are more readily contacted by the miticide.

Using IPM to Manage Turf Insects

Good cultural practices are the primary method for managing insect damage to turfgrass. Growing appropriate grass species for a particular location and providing lawns with proper care are especially important. Practices such as irrigating and fertilizing have a major impact on lawn health. Physical controls, such as thatch removal, choice of mowing height and frequency, and providing grass with more light by pruning tree branches, are also important in certain situations. Naturally occurring biological control may limit some insect pests.

The need for insecticides is greatly reduced if proper cultural practices are followed. Insecticides should never be applied unless a pest is identified and detected at damaging levels. If insecticides are necessary, choose materials that have minimum impacts on beneficial organisms and the environment.

If you suspect a billbug infestation, look for piles of fine frass at the base of turfgrass plants. In areas where frass or damage is evident, dig up the turfgrass to look for grubs.Treat when one or more grubs are found per square foot of turfgrass. Apply nematodes to moist turf and irrigate following application of either nematodes or chemical insecticides to move the material into the zone of larval feeding activity.

Preventing Pest Problems

The best way to prevent damage from turf pests is to keep grass healthy. Healthy landscapes require few, if any, insecticide treatments. Also, if the turfgrass is under stress and a pesticide is applied, it stands a greater chance of suffering phytotoxic damage from the pesticide itself.

Care for Turf Properly

There are a number of grasses available for planting. These grasses are often referred to as either cool-season grasses (examples include annual ryegrass, bentgrass, fine fescue, Kentucky bluegrass, perennial ryegrass, and tall fescue) or warm-season grasses (bermudagrass, kikuyugrass, St. Augustinegrass, and zoysiagrass). Warm-season grasses produce most of their growth during summer and usually have a dormant period when they turn brown during winter. Cool-season grasses are green year-round, but produce most of their growth in spring and fall. The type of grass and the varieties within each type vary in their shade tolerance, salinity tolerance, water needs, disease resistance, and cultural needs. A formerly thriving turf variety may decline with changes in light, such as more or less shade caused by growth or removal of nearby trees. Selection of the appropriate grass species and variety will allow you to grow a hardy landscape with minimal maintenance inputs.

To detect chinch bugs, adult billbugs, and caterpillars (shown here), perform a drench test by mixing 1 to 2 fluid ounces (2-4 tablespoons) of dishwashing liquid to a gallon of water. If you are using a concentrate version of a dishwashing liquid, 1-1/2 tablespoons per gallon of water is adequate. Two gallons may be required where soils are dry. Apply the solution to 1 square yard of lawn as evenly as possible using a sprinkling can. Test an area that includes both relatively healthy grass and adjoining unhealthy grass. The drench will cause insects to move to the surface. During the next 10 minutes, identify and count the number of pest insects. photo: Jeff Millar,Oregon State University

Care for Turf Properly

Inappropriate irrigation is the most common cause of lawn damage. Overwatering (shallow, frequent sprinkling) retards deep root growth and increases lawn susceptibility to stress. Poorly maintained sprinklers can apply too much water in certain spots while underwatering other areas. Brown spots from uneven water applications occur frequently and are often caused by improperly spaced irrigation heads, sunken or tilted heads, or unmatched heads that apply differing amounts of water. Correcting these physical problems with irrigation systems can decrease water waste by over 50%, decrease water bills, and most importantly, improve the health of your lawn. Lawns should be irrigated deeply and no more often than twice a week.

Appropriate fertilization encourages a dense, thick lawn that allows grass to tolerate some insect feeding. The appropriate timing and amount of fertilizer (primarily nitrogen) varies depending on factors including season, grass species, and local growing conditions. In general, most grasses used for lawns require from 3 to 6 pounds of actual nitrogen over a 1,000-square-foot area annually during their active growing season.

The drench test does not indicate the presence of billbug larvae, black turfgrass ataenius larvae, or white grubs (shown here). To detect white grubs, dig or cut beneath thatch and examine the soil around roots and crowns (where roots and stems meet). Look for the white, legless larvae of billbugs (a weevil) or the C-shaped, six-legged larvae of scarab beetles such as black turfgrass ataenius and masked chafers. When these are numerous, roots are eaten away and turf often can be rolled back like a carpet. If you find more than one billbug larva, six white grubs, or 40 black turfgrass ataenius grubs per square foot, control may be needed. photo: gardensafari.net

Biological Control

Certain insects, other invertebrates, and microorganisms that occur naturally in lawns feed on or parasitize lawn pests. This type of control, called biological control, may help to prevent many lawn-dwelling insects from becoming pests.

To protect beneficial insects, avoid using broad-spectrum pesticides that will kill them along with the pests. Biological pesticides containing organisms such as Bacillus thuringiensis (Bt) and beneficial nematodes are commercially available for controlling specific lawn insects. These materials have minimal impacts on natural enemies of insect pests and other beneficial organisms such as earthworms. Birds, moles, and other vertebrates also feed on lawn insects from time to time.

Detecting Problems in Your Lawn

An indication that a lawn may be infested with insects is when the adults (e.g., moth or beetle stage) of pests are drawn to lights at night or when vertebrate predators (birds, raccoons, or skunks) are digging in your lawn for caterpillars and grubs. However, the insects coming to light may be drawn from far away and vertebrate activity is not a foolproof indicator. They may be feeding on earthworms instead of insects; also, vertebrates will return to where they previously found food, so they may dig in lawns even if insect pests are no longer abundant. If you observe damage, the next step is to determine the actual cause. If you think the damage is caused by insects, confirm your suspicions by looking for the pest.

Sources: www.epa.gov/opp00001/factsheets/ipm.htm, www.ipm.ucdavis.edu, Biocontrol Reference Center: The History of Integrated Pest Management

The History of Integrated Pest Management

The introduction of DDT In the mid 1940’s, along with other chemiThe introduction of DDT In the mid 1940’s, along with other chemicals led to almost total dependence upon chemical pesticides. This dependence however, led to concerns about the adverse effects of excessive use of pesticides on the environment.

The basic biological concepts of Integrated Pest Management have been practiced for years and the philosophical concepts are intertwined in the practice of IPM.

Trial and Error: About the time humans started aggregating into villages and began planting selected food crops in clusters near rivers in fertile valleys, pests became an increasing challenge. They had to live with the ravages of pests of all types that attacked them and their crops. Through trial and error, humans began to learn how to improve conditions and control the environment. People learned to perform cultural and physical control practices for crop protection. Methods such as destroying or using crop refuse, roughing diseased plants, tillage to expose an eliminate soil insects, removal of alternate hosts off pathogens and insects, timing of planting, crop rotation, trap crops, determining optimum planting sites, pruning, dusting with sulphur, and others reduced damage potential to many crops from many pests. These cultural and physical control methods are still viable today.

Charles W. Woodworth, (1865-1940) Emeritus Professor and founder of the Entomology Division at the University of California, Berkeley, made many significant contributions to the science of Entomology. Most notably, he is credited with first breeding Drosophila in quantity while at Harvard.

The 1800’s: These cultural and physical methods of crop protection were developed, refined and used into the late 1800’s. As crop production methods improved, larger and larger acreage of crops were cultivated, an less reliance made on diversified agriculture. Equipment became larger and faster, and cultivation of larger acreage became feasible – monoculture replaced diversification. Some pest problems no longer could be controlled by the known combinations of cultural and physical practices, so the search was on for more effective pest control measures. A great number of noxious mixtures were tried with few beneficial results, until the discovery of “Paris Green” in 1870 for insect control and, in 1882, the discovery of “Bordeaux Mixture” for control of fungi. These discoveries ushered in an age of chemical research leading to the development of inorganic chemicals in early 1900 for pest control in agriculture until the 1940’s. Crops resistant to insects and plant disease were known, but development of resistant cultivated varieties was not pursued until after 1900. The development and use of cultural controls for crop protection almost disappeared from crop production practices.

However, there were some early advocates of less reliance upon pesticides. Stephen A. Forbes, University of Illinois, adopted the word “ecology and applied ecological studies for insect studies in agricultural crops in the 1880’s Charles W. Woodworth, A.E. Michelbacher (University of California, and many others stressed the importance of ecology in insect control. A highly sophisticated system for cotton boll weevil control had been developed by 1920, and economic thresholds were identified to initiate spray treatments with calcium arsenate. In spite off some of these early success stories, there was a gradual shift toward dependence upon chemical pesticides. Although there was some reported resistance of pests to pesticides, these were largely ignored. It was noted that after treatments with the inorganic insecticides, other pests emerge and populations were accentuated. In the mid 1940’s, the introduction of DDT and other organochlorine chemicals and the organophosphates and carbarnates later, led to almost total dependence upon chemical pesticides. This eventually led to concerns about the adverse effects of excessive use of pesticides on the environment, financial burdens from increasing costs of pesticides, and health hazards to applicators and others.

Among the many contributions of A.E. Michelbacher (1899-1991) to agricultural entomology was the development and application of control programs for many of the insect pests attacking important California plants.

Modern Era: In the late 1960’s, a movement to develop more environmentally benign methods began. Although economics was the prime driver to use crop scouting to determine spray schedules, it was a first real step toward an IPM approach. It wasn’t long before some scouting approaches started noticing increased numbers of parasites and predators when sprays were delayed or eliminated. In the 1970’s, researchers began to identify and develop systems that integrated many of measures to reduce pest populations to levels below damaging levels requiring pesticides. IPM was formulated into national policy in February 1972 when President Nixon directed federal agencies to take steps to advance the concept and application of IPM in all relevant sectors. In 1979, President Carter established an interagency IPM Coordinating Committee to ensure development and implementation of IPM practices.

In the 1980’s, some pioneering advocates of IPM began applying IPM principles an practices to urban sites. Since that time, IPM systems have been developed and used successfully at urban sites such as schools, parks, hospitals, and nursing home