June bugs are one of Florida’s most common warm-season beetles, showing up in large numbers from late spring through summer. They belong to the genus Phyllophaga, which contains nearly 300 species across North America, with over 100 species producing the fat white grubs that chew through Florida lawns. You’ll also encounter the green June beetle (Cotinis nitida), a more brightly colored relative that shares the same seasonal timing.
What June Bugs Look Like
Adult June bugs are stocky, oblong beetles ranging from about half an inch to one inch long. Most species in Florida are glossy and yellow to dark reddish-brown or black. The green June beetle is the flashy exception, with metallic green coloring that makes it easy to spot on fruit or flowers.
The larvae, called white grubs, are what most Florida homeowners actually deal with. These C-shaped, cream-colored grubs grow from three-quarters of an inch to nearly two inches long. They have a brown head, three pairs of legs, and a slightly darkened rear end where soil shows through their translucent body wall. If you dig one up and flip it over, true Phyllophaga grubs have two parallel rows of tiny spines on the underside of their last body segment, which distinguishes them from lookalike larvae.
Why They Swarm Porch Lights
Adult June bugs are nocturnal. They spend their nights feeding on foliage and flowers, sometimes causing visible damage to ornamental plants, and they’re strongly attracted to artificial light. That’s why you’ll find them buzzing clumsily around porch lights, streetlamps, and lit windows during warm evenings from May through July. They’re harmless to people. They don’t bite or sting. The adults are mostly a nuisance, bouncing off screens and accumulating on porches. Switching to yellow-tinted outdoor bulbs or turning off unnecessary lights reduces the swarms considerably.
The Three-Year Life Cycle
What makes June bugs unusual is how long they spend underground. The brown Phyllophaga grubs take a full three years to develop into adults. During that time, they live in the soil beneath your lawn, feeding on grass roots and organic matter. Adults emerge in late spring, mate, and females burrow back into the soil to lay eggs. Those eggs hatch into tiny grubs that spend years growing through three larval stages before pupating and finally crawling out as beetles.
This extended cycle means grub damage can build gradually. A lawn might look fine one year and start thinning the next as the same generation of grubs grows larger and eats more roots. In Florida’s warm soil, grubs remain active for much of the year, unlike in northern states where cold winters force them into dormancy.
Spotting Grub Damage in Your Lawn
The telltale sign of a grub problem is grass that pulls up easily from the soil, almost like lifting a loose carpet. That happens because the grubs have eaten through the root system below. Damage typically becomes most visible in spring, when the lawn is trying to green up but the roots aren’t there to support it. Brown, thinning patches that don’t respond to watering are a classic indicator.
Before blaming grubs, though, you need to check the numbers. Dig up a few square-foot patches in the damaged areas and count what you find. A healthy lawn can outgrow a small grub population. You generally need to find five or six grubs per square foot before they’re the actual cause of the decline. One or two per square foot is normal and not worth treating.
Wildlife That Digs Up Your Yard
Sometimes the first sign of a grub infestation isn’t the grass itself but the animals tearing it apart. Armadillos, raccoons, skunks, and moles all feed on white grubs and will dig through turf to get them. In Florida specifically, white ibis and sandhill cranes are reliable indicators. If you see a flock of ibis methodically probing your lawn, they’re almost certainly after grubs or other soil-dwelling larvae. Even dogs can smell grubs near the surface and will sometimes dig them up.
This secondary damage from wildlife can actually be worse than the grub feeding itself. An armadillo rooting through a lawn in one night can leave it looking like someone took a rototiller to it. Controlling the grub population is often the only lasting way to stop the digging.
When and How to Treat Grubs
Timing matters more than product choice when it comes to grub control. Preventative treatments work best when applied in April or May, before eggs hatch or while grubs are still tiny and vulnerable. If you’ve missed that window, curative treatments applied from July through August can still reduce populations, though larger grubs are harder to kill.
For a chemical-free approach, beneficial nematodes are effective biological control agents. Two species target white grubs specifically: one that actively hunts prey below the soil surface, and another that works best against grubs in the upper soil layers. Apply nematodes in the evening, since they’re killed by sunlight and heat. The soil needs to be moist but not waterlogged, and soil temperature should be above 60°F, which is rarely an issue in Florida. Water the lawn before and after application. A second treatment about two weeks later improves results. The nematodes carry bacteria that kill grubs within a few days of infection.
Nature also provides some control without any effort on your part. Parasitic wasps and flies prey on June bugs, and a naturally occurring fungus called Cordyceps infects grubs in the soil, killing them before they ever reach adulthood. A yard with diverse plantings and minimal pesticide use tends to support these natural predators, keeping grub populations lower over time.
Green June Beetles vs. Brown June Beetles
Florida residents often see both types and wonder if they’re the same insect. Brown June beetles (the classic Phyllophaga species) are the more common lawn pest. Their grubs stay underground, feeding on roots, and adults are drawn to lights at night. Green June beetles are larger, more vividly colored, and behave differently. Their grubs sometimes crawl on the soil surface, and the adults are active during the day, often found feeding on ripe fruit, especially figs, peaches, and tomatoes. Both belong to the scarab beetle family, but if your concern is lawn damage, the brown species are the ones to watch for.