Yea! The air is finally warm, and many of us are out late, enjoying the evening. That’s when it happens: Seemingly huge (well, not mammoth) insects buzz past – and maybe even bump into or land on you (especially if you’re near street or porch lights). While it can freak some people out, it’s really not all that bad. It’s just that time of year for Junebug adults to be buzzing about – enjoying the night just like the rest of us. Although these big beetles may startle you, they’re pretty harmless.

Junebug on hand

These clumsy beetles are attracted to lights at night, so turn off your porch light so you can enjoy the warm evenings without the flybys.

Photo Credit: ©2004 Buglady Consulting

Junebug on leaf

Adult Junebugs munch on tree and shrub leaves, but they generally don’t do any damage.

Photo Credit: ©2005 Buglady Consulting

Junebugs, or May/June beetles, are the adults of a particular group of white grubs in the genus Phyllophaga. They range in length from ¾-1¼ inches, depending on the species. They’re oblong and usually shiny, reddish-brown to almost black.

White grubs in this genus take three years to complete their life cycle. The adults that emerge in late spring or early summer fly around in the evening looking for food and mates. Like many nocturnal creatures, they’re attracted to light – including the one on your porch. After mating, females go into the grass and lay their eggs in the soil. After three or four weeks, the eggs hatch, and lil’ itty-bitty white grubs emerge to feed on grass roots and grow throughout the summer.

As fall approaches, the grubs move down deeper into the soil. This is where they remain until next spring. Once the soil warms up a little, the grubs move back up in the soil to feed on grass roots again. They spend the second entire summer feeding. Then, like the year before, the grubs move back deeper into the soil when fall returns.

In their third year, the grubs move back up in the soil to feed on grass roots until May or June. Then they pupate (the process of changing from larva to adult) right in the soil. By late summer, they’ve already made the change into adults, but they remain in the soil until the following spring – when they emerge to mate and feed (and try to get into your hair).

Junebugs don’t feed on turf, but they do eat the leaves of many other plants, including trees and shrubs. This typically results in small holes left in young leaves, but it usually doesn’t damage your plants. In fact, it’s really not necessary to do anything to control the adults unless infestations are overwhelming.

But do keep in mind that the beetles’ offspring may be damaging to your lawn, so remember to check your grass during summer for the presence of white grubs! Your local Extension office or garden center should have information on how many grubs per square foot your lawn can handle. They’ll also share the best management methods if you need help.

So as the weather heats up and you find yourself enjoying the great outdoors – along with the occasional Junebug run-in – please try to remember that these seasonal guys are pretty harmless. Like you, they’re just trying to enjoy the warm air!