In this guide, you’ll learn about the most common lawn pests and how to control them. Insects that damage turf grass can be categorized into two groups: Surface Pests and Subsurface Pests. Surface pests, as you can guess, feed on turf grass above the surface of the plant and can easily be seen. These include chinch bugs, sod webworms, armyworms and cutworms. Subsurface pests are trickier to identify, and feed below the surface on the roots of healthy turf grass. These include white grubs and billbug larvae.
For the purpose of this article, we are going to identify the most common surface pests and how to control them.
Surface Activity Clues
- Turf is yellow, brown or orange.
- Striped caterpillars are present
- Grass blades are chewed off or have notching along the blades
- Birds are frequently feeding in the turf
- Moths are flying low and frequently along the turf
Subsurface Activity Clues
- You have the ability to pull turf up like a carpet. The roots have been destroyed and come up easy.
- Turf is spongy when you stand on it (in well drained soil)
- Turf is not responding to irrigation
- Moles, skunks and raccoons are digging up turf (to feed on larvae)
Insect Control Methods For The Most Common Lawn Pests
While chemicals are probably the go-to instinct for how to control the most common lawn pests, there are other options. In the pest control industry, we urge clients to first adhere to Cultural Controls. Cultural controls with turf grass is keeping the turf grass extremely healthy, so that insects or weeds can not gain a foothold. Cultural controls for insect management consist of fertilizing, proper irrigation (an inch of water per week), turf aeration, and thatch control. When lawns are compact, have lots of thatch, and are not being fertilized, insects will have no problem taking over a lawn.
Biological Controls are the introduction of biological organisms into the environment to control pests, such as a predator or Biorational Insecticides. Biorational insecticides are insecticides that are derived naturally, and are much less toxic to the environment. These insecticides will also have a lesser impact on other insects which may be causing no harm to your turf grass.
Chemical Controls are used for when a pest population is too great for Biological controls and Cultural controls. Chemical controls are used to either prevent or treat an insect problem. If you are curing an insect problem, turf grass damage has already been done. Preventative controls for white grubs are less toxic to humans than the products available to for curative treatment, so we tend to include a preventative grub control product in treatment plans.
Pest Identification And Management For How To Control Lawn Pests
The sad reality is that pests love healthy turf grass. The nicer your lawn is, the more likely pests are going to try to nest and feed on the precious turf grass you have worked hard on creating.
Here, we identify the most common pests in turf grass and how to manage them.
In the larvae stage, sod webworms range from a cream to dull gray color. They can grow about 3/4 of an inch long, and the bodies feature many pairs of dark spots.
The larvae chew off leaves and stems just above the crown of turf grass. The crown is the area sticking out just above the surface. These areas, if left unchecked, will discolor into a brown patch that can grow to the size of a hockey puck. Another indicator sod webworms are large numbers of moths flying above the surface during the night.
How To Control Sod Webworms
The good news is that sod webworms rarely will kill turf unless the turf is being stressed by drought. Because the larvae are not attacking root systems, the chance of survival is increased. Sometimes heavy watering can even mask the sod webworms damage.
Most control measures for sod webworms are used on an as-needed basis. This means monitoring the turf grass for infestations, and making sure a chemical application is needed. If you are adhering to proper cultural controls, the use of biological and chemical controls is most likely not needed.
Armyworms and Cutworms
Similar to the sod webworm, these worms can cause damage in their larvae stage. When fully matured, they become moths. The caterpillars are dull colored and smooth, and can grow one to two inches long. At this size, these larvae are ferocious feeders and can cause issues. An easy way to know if you are dealing with armyworms or cutworms is by poking the caterpillar, and if it curls up into a “C”, that’s how you know it’s a cutworm.
Damage Signs Of Armyworms and Cutworms
The larvae chew off leaves close to the base of the turf grass. These areas, if left unchecked, will discolor into a brown patch that can be one to two inches in diameter. Another indicator of armyworms and cutrowms, similar to sod webworms, are large numbers of moths flying above the surface during the night. Large numbers of birds feeding also can indicate cutworm presence.
How To Control Armyworms and Cutworms
Wet weather favors the bacteria that is lethal to armyworms and cutworms. These pests tend to thrive in drought stricken lawns. The best way to control the most common lawn pests, armyworms and cutworms, once again is by using proper cultural controls. These pests are rarely a problem when turf grass is cut higher. They tend to infest golf courses and lawns that are cut too short. They can be easily controlled with insecticides, but that should be reserved until an outbreak is noticed. Apply the insecticide as late in the day as possible since these pests like to feed at night.
Chinch bugs are one of the most common lawn pests. The most damaging stage of a chinch bug’s life is during the nymph and adult stage. These bugs do not undergo a metamorphosis like the armyworm or sod webworm, and can be damaging to turf grass in the nymph stage. The nymphs are bright red-orange with a white band around the abdomen. Older nymphs progress to an orange brown, then to a grey, and finally as adults, black. They are tiny insects, only about 1/6 of an inch long.
Damage Signs Of Chinch Bugs
Grasses will turn yellow and then brown from chinch bugs because they suck the juices from the plant. Damage is most severe during drought stressed lawns. They prefer to feast on fescues, ryegrass and zoysia grass, all very common in Pennsylvania. Damage from chinch bugs will usually be seen in late June to mid-July, and a second generation of nymphs can also strike through August.
How To Control Chinch Bugs
Endophyte-enhanced grasses can help prevent chinch bug damage. As stated before, proper cultural controls will help mask the damage done by chinch bugs. Proper irrigation, fertilizing, and mowing at a healthy height will reduce stress on turf grass and make them more resilient to chinch bug feeding. Heavy rainfall in June and July will also reduce the amount of eggs that hatch.
Chemical controls can make quick work of chinch bugs, but make sure to properly identify the density of chinch bugs before treating. The earlier you treat chinch bugs in their life cycle the better. These bugs are surface and thatch dwellers so excess watering after an application can reduce the effectiveness.
How To Control The Most Common Lawn Pests
Utilizing all three pest control methods (cultural, biological and chemical) can be the best way to treat surface pests. We encourage healthy cultural control practices before moving on to biological or chemical controls. When dealing with surface pests, the greater your cultural control, the less likely you are to have an issue with surface pests. Visit these articles on the importance of lawn aeration or broadleaf weed control in order to better understand cultural control methods.