“June bug” refers to any of the 100 species of beetles that are related to the scarabs familiar from ancient Egyptian iconography. There are many common names for the June bug such as: “June beetle” and “May beetle.” The most common June bug is reddish-brown in color and one-half to five-eighths inches long. Because they are part of the beetle family, they have shiny wing covers, called elytra.
The June bugs are classified as chafers, meaning they feed on any vegetation, specifically leaves. June bugs are known to cause damage to gardens, lawns and pastures.
Their diet involves flowers, fruit, grass, food crops such as grains (wheat, corn, etc.), decaying organic material and sap. (Their scientific name is, Phyllophaga, which is Greek for “leaf eater.”) They begin feeding at dusk through the evening hours in order to avoid predators. Therefore, June bugs are nocturnal.
June Bugs and Light Attraction
These bugs are attracted to light but are generally harmless. It does make sitting outside on your patio or porch very unpleasant as the June bugs love to bump and buzz against the window or even your window screens. As they seek light even the light inside your home can attract June bugs in big numbers. These daily activities are a favorite pastime in the Summer months in the United States which can make it challenging to enjoy the Summer nights outdoors.
Scientists are still unconvinced on the precise explanation for this illumination behavior. There have been many speculations regarding this theory, but no single theory can account for why so many different nocturnal insect species gravitate to sources of light.
The Life Cycle of a June Bug
Adult June bugs are able to lay 75 to 100 eggs underground in early to midsummer. After about 18 days, larvae surface from the eggs. The larvae are legged worms about 1 inch long with brown heads, and it is during this exact time that the insect can be extremely damaging. Depending on the species, the grubs can spend one to three years underground, chewing plant roots as they make their way through three molt phases. During the colder winter periods, the grubs retreat deep into the soil and hibernate before becoming active again in the spring. At the final metamorphosis of the larval stage, the grubs form pupae that will hatch into new adult beetles the following spring as the cycle then repeats itself.
These annoying flying beetles that you will see on summer evenings are only the beginning of a larger problem. Sadly, you will begin to see where the eggs and root-destroying grubs are next up as a larger problem. Depending on the species, the time from egg to grub to pupa to adult can take one to three years. The real reason to rid your yard of June bugs is not just to make your evening recreation more pleasant but to save all of your flowers, plants, garden and trees on your lawn from grubs.
How To Spot Grubs And June Bugs
There are several signs that indicate you may have a problem either with adult June bugs or their larvae:
- You have spreading brown patches on your lawn. This is a sign that underground grubs are likely feeding on the roots of turfgrass plants. Large patches of dying grass may be so loosened from the severed roots that you can lift them up by hand.
- If you see large flying beetles on Summer evenings after dark. June bugs are insects that are attracted to light and are nocturnal insects. They will appear after the sun sets on summer evenings.
- Any of your plant or tree leaves have tattered holes. The adult beetles will feed on above-ground plants. Japanese beetle damage can be especially harmful.
- You see divots that have been dug all over your yard lawn overnight. These small holes are often created by raccoons, skunks, or other carnivorous animals searching for grubs to eat. In some regions, armadillos are the culprit as they are eaters of grubs.
- Perhaps you have gophers or a mole problem. Gophers and moles also eat grubs, so, if you have an issue with either of these, the cause of them may be a grub problem.
Be sure to monitor your entire landscape for such signs and follow up upon their detection by confirming the presence of these insects. For verification that grubs are present, simply dig up some grass or earth in your lawn, and inspect the soil for grayish-white, caterpillar-like bugs that curl up into a “C” like shape when disturbed. For proof that the adults are present, walk your entire landscape carefully, and inspect the leaves of your trees and plants for beetles and their destruction.
How To Get Rid Of June Bugs
You will need to detect the tell-tale signs of a June bug infestation, such as damaged plants or dead patches of grass, you may have a problem with ground-dwelling June bug larvae. To assist in June bug control you will need an effective method for helping curb your lawn from attracting their larvae. The best thing you can do is to create and maintain a healthy lawn which involves overseeding thinned-out areas of your grass or turf.
Then follow these steps to rid your landscape of June Bugs:
Trap Adult Insects
Not all June bug infestations are regarded as major enough to require serious remedies. Experts suggest that an otherwise healthy lawn can support as many as five to 10 grubs per square foot—the number of grubs will be evident if you dig up a 1-square-foot patch of turf. This number of grubs indicates you will probably face a few adult beetles cruising around the nighttime landscape come the following summer, but these can be trapped with a mixture of 1/2 cup molasses and 1/2 cup water placed in a narrow-necked container. There is also a variety of commercial beetle traps available for purchase that do much the same thing: lure and trap beetles in a container holding a sweet concoction.
Trapping adults will stop the reproduction cycle. But if you have larger numbers of grubs, trapping adults won’t be sufficient to control the population.
Apply Milky Spore To Get Rid of June Bugs
Another grub-control measure considered to be organic is milky spores, a bacterium that can be effective at controlling many types of grub beetles, including Japanese beetles. It depends on soil that is fairly warm, however, so it may not be the best choice for northern climates. Fall is considered a good time for application since the grubs are usually fairly close to the surface at this time. Milky spores will not have much success if applied in the spring and summer or when the soil is too dry.
Milky spores are mixed with water, applied with a sprayer or as a granular powder, and then watered thoroughly. It may take several years of repeated treatment to bring severe infestations under control.
Apply Beneficial Nematodes
Nematodes are microscopic soil worms that feed on the larvae of various insects. They are increasingly popular as a natural, non-toxic control for various damaging pests. There are many species of nematodes, but for lawn grubs, choose a species such as Heterorhabditis bacteriophora, which will also control Japanese beetle grubs. Nematodes should be applied when the grubs are active and present; in most regions, midsummer to late summer is the ideal time. If applied too early or too late, the application will be wasted.
Mix the nematodes with a garden sprayer, and then apply to a wet lawn in the evening. Immediately water the nematodes thoroughly so the solution drains down into the soil. You may need several applications over a period of two or three years to fully control grubs and the subsequent June bugs, but, used correctly, nematodes are a very good control measure.
Apply a Preventive Insecticide in June or July To Prevent and Infestation of Grubs
Another option is to apply an insecticide containing imidacloprid, thiamethoxam, clothianidin, or chlorantraniliprole in early to midsummer. However, be aware that these are preventive insecticides that kill only the newly hatched grubs. They will not kill mature grubs, eggs, pupae, or burrowing beetles. Thus, timing is quite critical with these products; too early or too late, and their effectiveness is largely lost.
Apply a Curative Insecticide in September
Although it’s always better to avoid chemical insecticides if possible, a serious grub and June bug infestation is one case in which insecticides may be necessary if you want to save your lawn. The most effective chemical remedy is to apply a product that contains carbaryl or trichlorfon in September. These are contact chemicals that will kill grubs and prevent them from pupating into adults. And, in September, the grubs are still close enough to the surface to be killed by the insecticide. These are known as curative chemicals rather than preventative since they will kill the insects in all their life cycle phases. Applied in September, these insecticides will kill as many as 80 percent of the grubs, thereby greatly reducing the following year’s June bug emergence.
Make sure to water these chemicals thoroughly. Toxicity to humans and most animals is moderate but well documented. Carbaryl is toxic to fish, so avoid applying it where run-off to lakes and rivers is possible. Trichlorfon in large concentrations is a central nervous system stimulant and should be used cautiously. Immediate watering will remove the chemical from the surface and reduce the hazard.