The May Beetle, commonly referred to as the June Bug, is a large, bulky insect frequently seen in North America during the warmer months of late spring and early summer. Its sudden, often clumsy appearance near outdoor lighting and windows prompts many people to question whether this beetle poses any threat to human health. While their size and noisy flight can be alarming, understanding the beetle’s anatomy and natural behavior clarifies its true role in the ecosystem.
Understanding Their Mouthparts
The question of whether a May Beetle can bite a human is definitively answered by looking at its mouthparts. May beetles, belonging to the genus Phyllophaga, possess mandibles that are categorized as chewing mouthparts. These structures are designed for masticating tough plant material, specifically grinding up tree leaves and roots. The anatomy of these mandibles is not adapted for piercing or injecting, making them physically incapable of inflicting a painful or damaging bite on human skin. If a person handles one, the beetle may instinctively grasp or pinch the skin with its legs or mouthparts, which is a harmless, clumsy mechanical action.
Identifying May Beetles
Knowing the physical characteristics of the May Beetle can help distinguish it from other insects. The adult beetles are generally robust and oval-shaped, measuring between one-half to one inch in length. Their coloration typically ranges from a light reddish-brown to a darker, sometimes nearly black, brown. A defining feature is the pair of hard, protective wing covers, known as elytra, which meet in a straight line down the beetle’s back.
These insects also possess distinctive antennae that are clubbed, meaning the segments at the tip can be fanned open. The combination of their stout body and hard shell contributes to their characteristic, somewhat heavy and awkward flight pattern. Their appearance is consistent across the hundreds of Phyllophaga species found throughout the continent.
Seasonal Appearance and Feeding Habits
The name May Beetle or June Bug is derived from the time of year the adults emerge from the soil, typically beginning in late spring. These adult emergence flights are often synchronized, leading to large populations being noticeable for a few weeks. They are primarily nocturnal, becoming active after sunset, which explains why they are frequently observed bumping into porch lights and windows. The adult life stage is spent feeding on the foliage of various trees and shrubs, which is the origin of their genus name, Phyllophaga, meaning “leaf eater.”
The larval stage, commonly known as white grubs, spends one to three years underground, feeding on the roots of grasses, ornamental plants, and trees. This root damage is the most significant harm caused by the species, potentially leading to patches of dead turf that can be easily pulled back from the soil. Adult beetles cause less damage, mainly light defoliation, and their primary threat is to lawns and crops, not to humans.