INSECT ID

about four to six weeks for the immature chinch bugs to go through their life cycle or mature. When temperatures begin to cool off in fall, the adults will return to the base of the plants to overwinter.

2. Grubs

Identification: Varying in size from 1/4 inch to 11/2 inches, white grubs have a creamy white, C-shaped body, six legs and a brownish head. The tail end of a grub is called the raster.

Damage: Grub damage looks like brown, thin or dead patches of grass that may be random, irregular or isolated. The grass may be loose and roll up easily. The turf can also feel spongy.

Top lawn care specialists describe early-summer insects and discuss how to control them.

1. Chinch bugs

Identification: Ranging in size from 3/16 to 1/5 inch long, chinch bugs are dark in color with shiny, light-colored wings and a black triangle in the middle along their shoulder (thorax). They have crossed forewings with silver markings.

Damage: Small, irregular yellow patches appear in some areas of the lawn, mostly in full sun exposure. As the insects spread, these patches enlarge up to 2 to 3 feet in diameter. Chinch bugs use their mouth parts to penetrate grass blades, sucking the fluids out and causing it to yellow and wilt. As the grass blades die, they change from green to pale yellow and eventually a reddish brown. Chinch bug feeding damage symptoms often look like drought stress.

Location: The hairy chinch bug occurs in the Northeast and Upper Midwest. The southern chinch bug occurs in Florida and Gulf Coast region. They are primarily found in St. Augustinegrass.

Control: Preventive practices can include moderate nitrogen fertilization, reducing the thatch layer or using resistant varieties of St. Augustinegrass. For chemical control, imidacloprid and pyrethroid insecticides like bifenthrin work well. Chinch bugs should be treated in the summer once the pest has been identified and a threshold of 20-25 insects per square foot has been reached. Use growing degree day models and historic knowledge of where chinch bugs have overwintered.

Additional info: When scouting for chinch bugs, pull the grass back in damaged areas at the edge of healthy turf. They’ll scatter near the soil at the base of the plants. Chinch bugs emerge in the spring and start to lay eggs. In the hottest summer months, it takes

Location: Grubs can be found throughout most of the continental U.S.

Control: Target the adult beetle. In the Southern U.S., treat chemically for adult grubs during June through mid-July to prevent adults from laying eggs into the soil. Using a contact product, eradicate what is in the soil at that time. Earlier-season preventive applications with a residual systemic insecticide can provide seasonlong control. Use a neonicotinoid insecticide or a diamide like chlorantraniliprole in the late spring to middle of summer when the larvae hatch. Diamides can be used in places where neonicotinoids are not allowed. Curative products like carbaryl or trichlorfon can be applied in the soil to control larval stages. For biological control, milky spore bacterium can be used.

Additional info: Adults emerge in midsummer to mate and lay eggs, which hatch in about two weeks. Once the eggs hatch, those grubs feed on the grass roots from late summer into the fall. If it’s known that a specific property is infested, be proactive and make sure that lawn has adequate fertility and moisture.

3. Billbugs

Identification: Billbug larvae are creamy white with a brownish head and are legless. When fully developed, they are 1/4 to 1/2 inch long with an elongated snout.

Damage: Adults will chew a hole in the grass blade and lay an egg. When the larvae emerge, they’ll feed from the inside out of that leaf blade. Early signs of damage are small irregular areas of brown, dying turf that spread. In damaged areas, pull back the grass, and it will break off at the soil. A powdery frass or excrement from the insect will be visible on the soil line.

Location: Billbugs can be found throughout the continental U.S.

Control: Billbug populations can be managed with resistant turf varieties, adequate irrigation and proper fertilization, as well as by raising the mowing height slightly. Pyrethroid insecticides can be used to reduce adult populations, and neonicotinoid and diamide insecticides can be used to target early-stage larvae. Apply insecticides in the spring to treat both larvae and adults. Imidacloprid and thiamethoxam insecticides can help get rid of insects before they move into the crown of the plant.

Additional info: The two common billbugs are the bluegrass billbug and the hunting billbug. Each can be found in warm- and cool-season turfgrass. If a property has a history of billbugs, more treatments may be required. Billbugs don’t fly or walk well.

4. Fall armyworms

Identification: Fall armyworms can be identified by an inverted white “Y” pattern along their face.

Damage: Armyworms cross the turf surface as a group and create a noticeable line between damaged and undamaged turfgrass. Damaged areas will often originate around a site where egg masses can be easily laid, such as sign posts and buildings and expand outward. Newly installed sod is more susceptible to damage.

Location: Found throughout the U.S., fall armyworms are more notorious in the Southeast for the extent of the damage they can cause but are an occasional pest in the Southwest from northern Texas across to California.

Control: Fall armyworms can have multiple hatches that last longer than some product residuals. Insecticides with active ingredients such as chlorantraniliprole and tetraniliprole can be effective for long-term control. Bifenthrin can be a highly effective when used curatively as a rescue treatment.

Additional info: Large armyworm populations can feel like they emerged overnight and do not stop eating from the moment they emerge from an egg until they pupate.

5. Cutworms

Identification: Cutworms are caterpillars that curl into a “C” shape when picked up. The black cutworm is a common species and can be identified by its overall “greasy” appearance, uniform body color and a typically brownish head. Some older larvae have a netting pattern over their eyes.

Damage: Cutworm damage looks like small pock marks. Closer examination reveals a small burrow and several grass plants around the perimeter of the burrow that have been sheared off near ground level. Often, these burrows are lined with green, pellet-like matter. This is caterpillar frass, or excrement.

Location: Cutworms can be found across the entire continental U.S, but this species does not tolerate colder temperatures.

Control: The first and second instars of the larval stages of cutworms and armyworms are small and easily missed. The “dish soap” method can be used to monitor for cutworms present in the thatch and soil surface. In healthy turfgrass, pour a mixture of 1 to 2 tablespoons of dish soap with 1 to 2 gallons of water over 1 square yard area and wait five to 10 minutes and see if any insects emerge.

Additional info: Cutworms get their name because they “cut” through plant stems at the soil surface when they are feeding, usually targeting young plants or seedlings.

Sources: Ben Hamza, Ph.D., product development director, FMC Corp.; Edwin Afful, Ph.D., insecticides product development manager, FMC Corp.; Julia Willingham, SiteOne business development manager, pest management; Amy Agi, Ph.D., field scientist for Corteva U.S. Turf & Ornamental; Matt Giese, technical services representative for the Midwest for Syngenta; and Richard Fletcher, technical services manager for turf & ornamental at Nufarm.

BY SARAH WEBB