What Is A June Bug Life Cycle Behavior And More?

June bugs are the beetles you see bouncing off porch lights on warm summer evenings. They are not harmful to people, but they can damage lawns and gardens. The name “June bug” actually covers several species of beetles in the genus Phyllophaga, and their life cycle is a long one that takes place mostly underground.

What Is a June Bug?

A June bug is a type of scarab beetle. They are also called May beetles or June beetles depending on where you live and when they emerge. Adult June bugs are reddish-brown or dark brown, oval-shaped, and about half an inch to one inch long. They are clumsy fliers and are strongly attracted to lights at night.

There are over 100 species of June bugs in North America alone. While they look similar, different species emerge at slightly different times in late spring and early summer. That is why you might see them in May in some regions and in July in others.

The June Bug Life Cycle

The June bug life cycle takes between one and three years depending on the species and the climate. In colder regions, the cycle tends to take longer because the insects develop more slowly in cooler soil.

There are four distinct stages: egg, larva, pupa, and adult. Most of the life cycle is spent underground as a larva, which is commonly called a white grub.

Egg Stage

Adult female June bugs lay eggs in the soil during early summer. They typically choose grassy areas or gardens with loose, moist soil. A single female can lay anywhere from 50 to 200 eggs in her lifetime. The eggs are small, white, and oval-shaped. They hatch in about two to three weeks.

Larval Stage (White Grubs)

When the eggs hatch, the larvae are small white grubs with brown heads and six legs. They immediately begin feeding on organic matter in the soil, especially grass roots. This is the stage that causes the most damage to lawns.

White grubs feed actively through the summer and fall. As winter approaches, they burrow deeper into the soil to escape freezing temperatures. In the spring, they move back up toward the surface and resume feeding. Depending on the species, the grub stage lasts from one to two years.

Pupa Stage

After the grub has grown large enough, it enters the pupa stage. The grub moves deeper into the soil, forms a protective cell, and transforms into a pupa. This stage looks like a resting beetle. It is soft and pale at first. The pupa stage lasts several weeks to a few months. During this time, the insect is transforming into an adult beetle.

Adult Stage

Adult June bugs emerge from the soil in late spring or early summer. They live only a few weeks. Their main job is to mate and lay eggs. Adult June bugs feed on the leaves of trees and shrubs, but this feeding rarely causes serious damage. The adults are most active at night and are strongly attracted to lights.

What Do June Bugs Eat?

June bugs have different diets at different life stages. The grubs feed on roots, grass, and other organic matter in the soil. Adults feed on the leaves of trees, shrubs, and other plants.

Adult June bugs prefer leaves from trees like oak, maple, and walnut. They also eat the leaves of ornamental shrubs and garden plants. While adult feeding can leave ragged edges on leaves, it rarely kills healthy plants. The real damage comes from the grubs.

White grubs feed on the roots of grass and other plants. A heavy infestation can kill patches of lawn. The grass turns brown and can be pulled up easily, like a loose carpet, because the roots have been eaten away.

Are June Bugs Harmful to People or Pets?

June bugs are not dangerous to humans. They do not bite, sting, or carry diseases. They may startle you when they fly into your face or hair on a summer night, but they are harmless.

For pets, the story is slightly different. Dogs sometimes eat June bugs because they are attracted to the movement. Eating a few June bugs is generally not harmful. However, the hard outer shell of the beetle can be difficult to digest. Some dogs may vomit or have an upset stomach after eating several. If your dog eats a large number of June bugs and shows signs of distress, contact your veterinarian.

Signs of a June Bug Infestation

If you have June bug grubs in your lawn, you may notice several signs. The most obvious is patches of dead or dying grass in late summer or early fall. These patches appear because the grubs have eaten the roots.

Another sign is increased animal activity. Skunks, raccoons, and birds dig up lawns to eat the grubs. If you see small holes or torn-up patches of sod, grubs may be the reason.

You can check for grubs by cutting a square foot of sod and peeling it back. Healthy grass should be firmly rooted. If you find more than a few grubs per square foot, you may have an infestation. In most cases, a small number of grubs is not a problem and does not require treatment.

How to Get Rid of June Bugs

If June bugs are damaging your lawn or garden, there are several control options. The right approach depends on the severity of the problem and the time of year.

Prevention and Lawn Care

Healthy lawns tolerate grub feeding better than stressed lawns. Water deeply but less frequently to encourage deep root growth. Mow at the proper height for your grass type, and avoid over-fertilizing, which can attract adult beetles looking for a place to lay eggs.

Some people use milky spore, a natural bacterium that infects and kills grubs. It takes time to establish and only works on certain grub species. It is not a quick fix, and results vary by region.

Insecticides for Grubs

If you have a heavy infestation, insecticides can be effective. Timing matters. Preventive treatments are applied in early summer before eggs hatch. Curative treatments are applied in late summer or early fall when the grubs are small and feeding near the surface.

Always follow the label instructions on any insecticide. Some products are restricted and may require a licensed applicator. If you are unsure, contact your local cooperative extension office for guidance specific to your area.

Traps and Lights

Adult June bugs are attracted to light, so turning off porch lights at night can reduce the number of beetles around your home. Bug zappers kill some adults but will not solve a grub problem. Traps are available, but they may attract more beetles to your yard than they catch.

Are June Bugs the Same as Japanese Beetles?

June bugs and Japanese beetles are both scarab beetles, but they are different insects. Japanese beetles are smaller, have a metallic green and bronze appearance, and feed in groups on the leaves of many plants. June bugs are larger, brown, and feed mostly at night.

Japanese beetles are an invasive species in North America and cause significant damage to ornamental plants and crops. June bugs are native and generally cause less damage. The grubs of both insects look similar, but the adults are easy to tell apart.

Do June Bugs Have Any Benefits?

Despite their reputation as pests, June bugs have a role in the ecosystem. They are a food source for many animals, including birds, mammals, and other insects. Grubs are an important protein source for skunks, raccoons, and some bird species.

June bugs also help with soil aeration. Their movement underground and their feeding on organic matter contribute to soil turnover. In small numbers, they are part of a balanced backyard ecosystem. Problems only arise when their populations grow large enough to damage lawns and gardens.

When to Call a Professional

If your lawn has large areas of dead grass and you find many grubs, professional treatment may be warranted. A lawn care professional can identify the species, assess the population, and recommend the right timing for treatment.

Your local cooperative extension office is a free resource. They can tell you the typical grub pressure in your area and the best time to apply treatments. They can also help you identify whether the damage is actually from grubs or from another cause, such as drought or fungal disease.