June Beetle

The June beetle, also called a May beetle, refers to a large group of scarab beetles in the genus Phyllophaga, family Scarabaeidae, order Coleoptera. Dozens of species across North America share the common name, all recognizable by their stout, rounded bodies and their habit of appearing in large numbers around porch lights in late spring and early summer.

These beetles are notable for their two-part life cycle: the adults are relatively short-lived nocturnal fliers, while the larvae, known as white grubs, spend one to several years underground feeding on plant roots, particularly grass roots in lawns and turf.

June beetles are a familiar seasonal sight across temperate regions and are often the beetle people encounter bumping clumsily against window screens or porch lights on warm nights.

• Stout, oval, robust body typically 12–25 mm long
• Coloration usually reddish-brown, chestnut, or nearly black, with a glossy or slightly velvety sheen
• Short clubbed antennae that fan open into flat lamellae, typical of scarab beetles
• Clumsy, buzzing flight, often colliding with lit windows and screens at night
• Larvae (white grubs) are C-shaped, cream-colored, with a distinct brown head capsule, found in soil rather than above ground

June beetles are found throughout North America, particularly in regions with grassy lawns, pastures, agricultural fields, and deciduous woodland edges where their root-feeding larvae can develop in soil. Adults emerge from the soil in late spring through early summer, generally from May into July depending on latitude.

Adults are strongly nocturnal and attracted to artificial lights, while larvae remain hidden below ground in turf, garden beds, and open fields year-round.

Adult June beetles are active fliers at dusk and after dark, feeding on the foliage of trees and shrubs such as oak, walnut, and birch, though adult feeding damage is usually minor. Their heavy-bodied, erratic flight and tendency to bump into lit surfaces make them a familiar nighttime presence in early summer.

The larvae, or white grubs, live underground and feed on the roots of grasses and other plants, making them a recognized presence in lawns and pastures. In the wider ecosystem, both larvae and adults serve as a food source for birds, skunks, moles, and other insectivorous animals.

June beetles undergo complete metamorphosis: egg, larva (grub), pupa, and adult. Females lay eggs in the soil in early summer, and the larvae hatch to begin feeding on plant roots, molting through three instars over the course of one to three years depending on species and climate.

Mature larvae pupate in an earthen cell in the soil, typically in late summer or fall, and the adult beetle either emerges that season or overwinters below ground before emerging the following spring. This extended underground developmental period explains why the same lawn can experience sporadic, multi-year population fluctuations.