Grub Damage

Grubs are small worm-like pests that feed on grass roots and organic material in a home lawn, eventually causing sections of it to die. Grubs are the larval form of several scarab beetles and are typically relatively easy to see. White grubs are pudgy, off-white larvae with brown heads and generally are bent in the shape of the letter "C." Our white grubs' adult beetles are either Japanese or masked chafers. Japanese beetles are shiny metallic green with coppery red wing covers. Masked chafer beetles are tan or straw brown and have a black stripe across their eyes and face. Adult beetles typically emerge and begin flying in June, laying eggs in July. The grubs feed rapidly and are fully grown in August or September. The grubs then move down in the soil to overwinter before moving back to the soil's surface in the late spring to pupate and emerge as adults.
Grub damage typically shows up as dead patches in the yard. The best way to check if grubs caused the damage to your lawn is to pull on the grass. If it comes up easily, you will likely have grub issues. Another sign-up has grubs if animals such as raccoons and skunks are digging up patches of your yard. If you suspect grubs, cut a one-foot square section of your lawn and peel back the grass to reveal the soil underneath (If you have a significant amount of grub damage, the lawn should peel easily). Sift around in the soil and count the number of grubs you find. If you see 10 or more, you have a major grub issue. Replace the area of sod you cut out and water it in thoroughly. If you found many grubs, your best bet might be to treat the lawn. There are two times to control grubs: the first is in April or May with products containing the active ingredient called chlorantraniliprole or use a grub preventer in July to kill the newly hatched grubs before they become a problem.

 

Have questions? Contact our office where our Horticulture Extension Agent will assist you with questions.

Phone: (316) 321-9660

Email: callae@ksu.edu