The term “June bug” or “June beetle” is a common, non-scientific name used across North America for several species of insect in the family Scarabaeidae, often called scarab beetles. They are known for their sudden emergence in late spring and early summer, which gives them their seasonal name. Because this common name covers multiple species, their appearance varies significantly, leading to confusion over whether the insect is brown, green, or another color. This variation is rooted in the distinct life cycles of the two primary groups that share the “June bug” moniker.
The Appearance of the Common June Beetle
The insect most widely recognized as the classic June bug belongs to the genus Phyllophaga, which encompasses hundreds of species sometimes called May beetles. These beetles generally display a muted, earthy palette, ranging from a light reddish-brown to a dark chestnut or mahogany color. Their bodies are stout, oval-shaped, and relatively heavy, typically measuring between one-half and one inch in length.
The wing covers, known as elytra, are hard and armored, usually possessing a slightly dull or subtly glossy finish without bright iridescence. Phyllophaga beetles are strictly nocturnal, emerging from the soil at dusk to feed on the foliage of trees and shrubs. They are strongly attracted to artificial light sources, such as porch lights, which is why they are often seen bumping clumsily against windows on warm summer nights.
Addressing the Green June Bug Confusion
The confusion over color is primarily due to the existence of a distinctly different species, the Green June Beetle, Cotinis nitida, which shares the common seasonal name. This beetle is characterized by a brilliant, velvety, metallic green coloration across its upper body and wings.
The sides and margins of their elytra often feature a contrasting trim of gold, yellow, or bronze, creating a striking, iridescent effect. Unlike their brown counterparts, Green June Beetles are diurnal, meaning they are active during the day, often seen buzzing low over lawns and turf. They are slightly larger and stouter than many Phyllophaga species, and their preference for soft, ripe fruits and tree sap sets them apart from the leaf-feeding brown June bugs.
Key Identification Features Beyond Color
Beyond the obvious difference in color, several structural and behavioral features help reliably identify the various June beetle species. Both the brown Phyllophaga and the green Cotinis nitida share a characteristic body shape, including a prominent, heavy abdomen covered by the hard elytra. A universal feature of scarab beetles is their antennae, which are clubbed or lamellate, meaning the last few segments fan out like small, layered plates.
The flight pattern offers another clue, as both types are known for their loud, distinctive, and often clumsy buzzing, which contributes to their reputation for “dive-bombing” objects. Furthermore, the common Phyllophaga species can be identified by the presence of fine, dense hairs, or setae, covering the underside of their body. The Green June Beetle, conversely, has a unique behavioral trait where its larva, known as a white grub, crawls on its back using stiff bristles.