White, C-shaped grubs found in soil often raise questions about their identity and connection to the familiar buzzing beetles that appear in late spring and early summer. This article explains the relationship between these subterranean dwellers and adult June bugs, detailing their shared life cycle.
Are Grubs June Bugs?
White grubs found in garden beds or damaged lawns are the larval stage of various scarab beetles, commonly known as June bugs. The term “June bug” refers to several species, including the European chafer (Rhizotrogus majalis) and various Phyllophaga species. These grubs are simply the immature form of these beetles. They develop underground before transforming into their winged adult stage.
The June Bug Life Cycle
June bugs undergo complete metamorphosis, a four-stage process: egg, larval, pupal, and adult. This cycle typically spans one to three years, depending on species and environmental conditions.
Adult female June bugs lay pearl-like eggs several inches deep in the soil during June and July. Within weeks, the eggs hatch into the larval stage.
The larval stage, or grub, is the longest phase, lasting one to three years. Grubs live underground, feeding on the roots of grasses and other plants. They grow and molt multiple times, increasing in size with each instar.
As fall approaches, mature grubs move deeper into the soil to overwinter. In late spring or early summer, the grub transforms into a pupa within an earthen cell. During this quiescent stage, the insect develops its adult structures. The adult beetle emerges from the pupal case in late May or June.
Spotting Grubs and June Bugs
Recognizing grubs and adult June bugs involves understanding their distinct characteristics and behaviors. Grubs have creamy white bodies, often with a darker posterior from ingested soil. They assume a characteristic C-shape when disturbed.
These larvae have a distinct brown head capsule and three pairs of legs near their head. They range from half an inch to over an inch long, depending on age and species. Grubs are commonly found in the top few inches of moist soil, especially in lush grass or garden beds.
Adult June bugs are robust, oval-shaped beetles, typically measuring half an inch to an inch long. Their hard exoskeletons range from reddish-brown to dark brown or black. These beetles are known for their clumsy, buzzing flight patterns, especially at dusk.
Adult June bugs are strongly attracted to lights at night, often congregating around porch lights or illuminated windows. They are most prevalent during late spring and early summer, particularly in June. While many white grubs are June bug larvae, similar-looking grubs can belong to other beetle species.