June bugs, also known as May beetles, are a familiar sight during late spring and early summer evenings across North America. These insects are scarab beetles, typically measuring between one-half to one inch in length, with thick, oval-shaped bodies. While most June bugs appear reddish-brown, some species can be dark green, often with a shiny exoskeleton.
The June Bug Life Cycle
June bugs undergo a complete metamorphosis, progressing through four stages: egg, larva, pupa, and adult. The adult beetles emerge from the soil in late May or early June, initiating their relatively short lifespan above ground, which usually lasts about one to two months. After mating, female June bugs burrow a few inches into the soil to lay their eggs, typically depositing 60 to 75 eggs over a two-week period during July and August.
These eggs hatch into larvae, known as white grubs, within two to four weeks. The grubs are C-shaped, cream-colored, and possess brownish heads, ranging from three-quarters of an inch to two inches long. This larval stage is the longest, lasting from 10 months to up to three years, as grubs feed on the roots of grasses, vegetables, and other plants underground. As temperatures drop, they burrow deeper into the soil to overwinter, resurfacing in spring to continue feeding.
Following their larval period, the grubs enter the pupal stage, in the spring of their second or third year. This transformation occurs underground and lasts three weeks. Once pupation is complete, the adult June bugs emerge, ready to repeat the life cycle.
Their Ecological Purpose
June bugs, through their different life stages, contribute to the ecosystem. The subterranean grubs play a role in nutrient cycling by breaking down organic matter in the soil. Their burrowing activity also helps aerate the soil, which can improve water penetration and support plant root growth. These actions contribute to the overall health and structure of the soil.
Both adult June bugs and their larvae serve as a food source for animals. Birds, such as crows and robins, feed on the protein-rich grubs, while nocturnal predators like bats, raccoons, skunks, and moles prey on both grubs and adult beetles. Lizards, toads, and other insects also consume June bugs, supporting a diverse food web.
Adult June bugs also contribute to pollination, though they are not considered highly efficient pollinators. They feed on flowers, and their movement from one plant to another can facilitate the transfer of pollen. This incidental activity aids in the reproduction of various plant species.
June Bugs and Their Surroundings
June bugs are recognized for their clumsy flight and attraction to light sources. Their bodies are relatively heavy and bulky, and their wings are not designed for highly agile maneuvers, leading to an erratic and bumbling flight pattern. This often results in them bumping into objects like windows or screens.
These nocturnal insects are strongly drawn to artificial lights. They may confuse these lights with natural navigational cues, like the moon, leading to disorientation. Their aggregation around lights is also linked to mating behaviors, as the artificial illumination can signal the presence of potential mates.
Adult June bugs are harmless to humans, as they do not bite or sting. However, their feeding habits can impact human environments. Adult June bugs consume the leaves of trees and shrubs, though the damage is typically minor for healthy plants.
The most significant impact on human surroundings comes from the larval stage. June bug grubs feed on plant roots, which can lead to noticeable damage in lawns and gardens, appearing as brown patches of dead or thinning grass. A lawn with a severe grub infestation may feel spongy underfoot. This root damage can also attract animals like raccoons and skunks, which dig up lawns in search of the grubs.