Cutworms

If you are/were related to a farmer, when you think of cutworms you invision them attacking your corn and beans. Typically these little caterpillars don’t do enough harm for damage to be visible but in rare cases they can cause damage that may go mistaken as drought issues or be misdiagnosed as another insect.

There are many different cutworms that attack turf, but not all cutworms have the same life cycle. For example, the black cutworm overwinters in warmer climates and the moths (adult form of the cutworm) migrate north in the early spring and deposit clusters of eggs on grasses and weeds. Both Bronzed and variegated cutworms also overwinter. The Bronzed cutworm overwinters as an egg while the variegated cutworm will overwinter as a partially grown larvae. Knowing the life cycle is important when scouting for turf damaging insects and using control methods.

Both the moth and the cutworm are night time creatures. Moths can lay up to 2000 eggs in its life span. You can find clusters of 10 to 100 eggs on any given leaf. Identifying the moth flight at night can give you an idea when to start looking for damage in your turf. The life cycle chart shows it only takes a minimum of 35 days for a cutworm to complete its life cycle.

When scouting for insects in your lawn it will help to pull back the canopy of the turf to reveal the thatch layer. In the case of cutworms you will have to force them out of the ground by using soapy water. Mix a few tablespoons of dish soap to a gallon of water and pour over the area you are inspecting. The soap will irritate the cutworm and force it to the sunlight.

Because cutworms are surface feeding caterpillars they are easy to control with liquid sevin, Bifenthrin, and other permethrins. As always if you have something wrong with your lawn and you cannot diagnose the issue do not hesitate to call in a professional you can trust.