Anyone who’s been in the green industry for more than a year knows that controlling turf pests is a complicated and multifaceted endeavor. Sports turf managers often find themselves smack dab in the middle of the delicate balance of effectiveness versus a multitude of complications including cost, timing, pollution prevention and interruptions in sports play.
The often-neglected step in pest control is scouting and monitoring. Actually, for veteran managers, it’s more often a “skip over” step. They know scouting should be carried out on a regular basis, but it always seems like there’s something more important to do.
Visual “on hands and knees” inspection.
One of the reasons why integrated pest management (IPM) works so well is because if one of the many components fails or is cost prohibitive, there are more options to choose from; that’s where scouting and monitoring fit in. When appropriate soil improvements, cultivar selection, cultivation, topdressing, fertilization, irrigation and mowing fail to adequately control an insect infestation, embarking on a thorough scouting and monitoring campaign can really bring results.
Scouting and monitoring
For the most part, the terms scouting and monitoring can be used interchangeably. Monitoring involves regular inspections to detect early signs of insects and their damage. Its primary goal is to detect, identify and describe pest infestations. All fields should be monitored on a regular basis during the growing season. The scouting interval may vary from one to two days to several months depending on the value of the field and nature of anticipated pest problems.
Sampling is a key step in determining the nature and status of pest issues. Sampling involves the use of specific techniques designed to detect and identify insect pests and assess their damage potential. Sampling may be initiated when an insect infestation is suspected, at appropriate times during a pest’s life cycle, or in historically infested areas. Enough samples must be taken to assure a reasonably accurate estimate of pest numbers in the sampled area.
When to look
Because it is difficult to remember, records on insect infestations should be maintained for each field. Information that should be included in this record are: dates of first detection and peak infestation; control attempts – product, rate and timing; weather conditions; and overall effectiveness of control.
Sampling for white grubs.
PHOTOS BY JAMES KALISCH, UNL.
Where to look
The anecdote about the boy looking for a lost nickel under the streetlight instead of where he dropped it because the light was better illustrates the importance of knowing where to look. The key to successfully locating developing infestations depends on knowing the history of the field, the life cycle of pests that have been a problem in the past and knowledge about where each potential pest lives and feeds.
How to look – monitoring protocol
In most turf maintenance situations, one or more of three basic monitoring techniques will provide the backbone of the diagnostic activity.
Visual inspections – Certain turf insects are most readily detected by visual inspections. Billbug adults, for example, can be observed as they wander across paved areas and pathways during warm spring weather. Annual bluegrass weevils can be detected by inspecting the clippings in mowing boxes from low-cut turf, and chinch bugs can sometimes be found by separating grass plants with the thumb and forefinger and examining the base of the plant. While visual inspections can be used to detect many insects, this approach is rarely as effective as other observation techniques.
Cup cutter samples – Make digging easy with something that golf course superintendents use every day – a cup cutter. Sampling with a cup cutter is perfect for determining how many subsurface insects are present in a random sample. Start by mapping the affected area. Take a sample from the center of the area, the edge of the area and 10 feet beyond it. Count the number of grubs (or other subsurface feeders) and compare it with the other samples to obtain an estimate of average infestation levels.
Turfgrass plug examination.
Soap and suds – If you suspect damage from sod webworms, cutworms, armyworms or chinch bugs, a simple soap and suds routine will help flush them out. Combine 1/4 cup of lemon-scented dishwashing detergent with 2 gallons of warm water. Evenly distribute this mixture over a square yard of affected turf. Using a watering can will help ensure the disclosing solution will be evenly spread over the target area. Wait five to 10 minutes after application for the insects to move to the surface, where they can be easily counted. As with the cup cutter technique, sample the center of the affected area, around the edges and beyond.
Tools of the trade
In any business, certain tools are germane to effectiveness. Fortunately, when it comes to monitoring for insects on sports fields, they’re not expensive or exhaustive. Here’s a rundown:
Your eyes – Probably the most important tool of all, being able to spot movement of little critters or the presence of feeding injury is crucial. Training under the tutelage of a veteran sports manager is one of the best ways to learn to utilize your eyes to key in on insects.
Hand lens – Most insects that feed on turf are fairly small. Magnification can be useful in helping you distinguish between, say, a chinch bug and a soil particle. Even with larger insects, a hand lens is often helpful in seeing important body features. In the case of white grubs, using a hand lens to observe the arrangement of hairs on the terminal abdominal segment will help you distinguish between pest and nonpest species.
Pocketknife – About as low-tech as you can get, but a pocketknife can be a useful tool for the sports turf manager. The obvious use is to cut out chunks of turf to inspect them more closely, but poking through thatch to look for surface feeders, such as sod webworms, and probing the soil for moisture content are other good uses.
Sweep net – Low-flying sod webworm adults can be easily collected with a sweep net. Using one will help you accurately identify the insect in question and provide a sense of the severity of the infestation.
Shovel – On some fields, it’s easier to use a shovel to inspect the thatch and sod than a pocketknife. A small shovel comes in handy when inspecting for moles and pocket gophers, as well as for obtaining soil samples.
Tin can and dish soap – A 5-pound coffee can with the top and bottom removed can aid in the detection of surface feeders. Sharpen the bottom edge, and then press it into moistened soil and fill with water. Insects such as billbug adults, chinch bugs and caterpillars will float to the surface where they can be identified and counted.
Use everything available
When you look at it closely, effective turf pest control is largely a matter of managing a jigsaw puzzle of factors. Reliance on just one or two of these factors is a sure path to failure. Successful turf pest control will always involve a rigorous and regular program of inspection and monitoring to confirm the presence of damaging pests and, if they are necessary, determine the best time to apply pest control agents.
John Fech is an extension educator specializing in turf and ornamentals at the University of Nebraska-Lincoln. Frederick P. Baxendale is a professor and extension entomologist with the University of Nebraska-Lincoln.