What Are June Bugs?
The June bug is also called the May beetle or June beetle. There are over 100 species of June bugs, and all of them start their lives as white grubs once they hatch from their eggs. These grubs can sometimes damage crops and young trees by eating the roots. People tend to lump June bugs, green June beetles, and Japanese beetles together as "white grubs", but they are three different insects.
What do June bugs look like? The adult June bug is about 1/2 inch to 1 inch long with a thick, oval-shaped body. All June bugs are brown, ranging from a lighter reddish-brown to a brown so dark it looks almost black. Adult June bugs come out at night to eat and mate. They are attracted to light and often buzz loudly around lighted doorways and cling to screened doors with their thin, jointed legs. June bugs are clumsy flyers and often run into walls and windows with a thud.
In the larval (grub) stage, they are 3/4 to 1 3/4 inches long, and their bodies curve into a C shape at rest. The larvae have brown heads and white bodies with six legs up near the head. The other end of the larvae is often enlarged and darker. To tell them apart from other types of grubs, look at their hind end. On the last segment of their bodies, June bug larvae have two rows of tiny spines that run side by side like railroad tracks.
What do June bugs eat? Adult June bugs eat the leaves of shrubs, trees, and other plants but don't usually cause major damage. For most types of June bug, one full life cycle takes three years. They live underground for most of their lives.
Year One: Adults come out of the soil in spring to mate and lay eggs. Larvae hatch from the eggs after about 3 weeks. The larvae eat the roots of many kinds of plants, especially grasses, vegetables, ornamental (decorative) shrubs, and tree seedlings. They will also eat rotting bits of plants they find in the soil. In fall, the larvae burrow down far from the surface and wait out the winter.
Year Two: In the spring, the larvae come back up near the surface to feed on plant roots again. This is the year of their lives in which they do the most damage, as they stay near the surface and continue to eat roots until the fall. They then burrow down to spend the winter deep underground again.
Year Three: The next spring, the larvae return to the surface to feed yet again on the roots of plants. In late spring, they cover themselves in a protective layer for the pupa stage, in which they turn into adult June bugs. These adult beetles do not come up out of the ground yet, though. They spend the winter underground, then appear as full-grown adults in May or June.
Where Do June Bugs Live?
June bugs are common throughout North and South America.
You might not notice June bug larvae in your yard unless you're digging in the garden or flower beds. The June bug spends most of its life cycle underground. Even in the adult flying stage, the June bug spends the daylight hours burrowed into the soil. You will likely only see the adult June bug buzzing and bumping around your porch lights at night in the summer. If you go looking for them at dusk or at night, you may find adults on the leaves of your trees.
Signs You Have June Bugs
As June bug larvae feed on the roots of your lawn, uneven patches of dead or dying grass may appear. The damage to the roots keeps the grass from taking in enough water for it to handle extreme heat or dry periods. If you can roll the sod back, there are not enough roots left to attach the grass to the ground. This is a sign that you are dealing with a large number of grubs.
You may notice birds pecking for the grubs when they are near the surface of the soil. Skunks, raccoons, and moles may come during the night and dig up the grass to eat grubs. If that happened, you would see a section of grass flipped over in the morning.
Adult June bugs leave small, uneven holes in the leaves of trees and other plants. The damage is usually so light that the beetles have moved on by the time you notice it.
Why Do You Get June Bugs?
June Bug larvae prefer pasture grasses. Damage to tree leaves (from adult June bugs) tends to happen near pastures. Grubs are most likely to damage new lawns planted where there was a pasture not too long before. The grubs from the pasture are still there and come up to eat the tender young roots of the new grass.
June bug grubs are most likely to damage grass that is not frequently watered. Grub problems at golf courses and in lush, well-watered lawns are probably from the larvae of a different type of beetle.
Are June Bugs Dangerous?
Do June bugs bite? No, they don't bite, sting, or otherwise harm humans.
How to Get Rid of June Bugs
Plant care. Fertilize your lawn in spring and fall. Water during dry stretches. The healthier a plant is, the better it'll be able to survive and recover from insect damage.
Identification. If you find grubs and are concerned about the damage they're causing, call your local Cooperative Extension office for help in identifying the insect. It can be hard to tell one type of grub from another, and there are different treatments for the grubs of different beetles.
Biopesticide. This is a spray that contains organisms that kill June bug larvae. Choose a biopesticide with either entomopathogenic nematodes or Beauveria fungal spores.
Insecticide. Use chemical sprays only when there's a lot of damage to the lawn. Most insecticides are poisonous, so store them out of reach of young children. When you are mixing or spraying insecticide, wear rubber gloves, safety goggles, a long-sleeved shirt, long pants, and rubber boots. Water the lawn after you spray insecticide to wash the chemical into the soil, then keep people and pets off the grass until it dries.
Spray insecticide mid-May to early August the year after damage occurs. Two insecticides people use on June bug larvae are halofenozide and imidacloprid. Don't spray unless you've figured out which insect is causing the problem. Broad-spectrum insecticides kill helpful insects as well as the ones you're trying to stop. You need those helpful insects to keep the number of pests under control.