**June Bugs** (genus *Phyllophaga*), also commonly known as May Beetles, are large, reddish-brown beetles whose larval stage, the **white grub**, is a common and destructive pest of lawns and turfgrass. The adults emerge in late spring or early summer (May/June), feed on tree and shrub foliage, and are a nocturnal nuisance, often clustering around outdoor lights. The major conflict, however, comes from the larvae, which live underground and feed voraciously on the roots of grasses and ornamental plants for one to three years.
Taxonomy and Classification
June Bugs belong to the order Coleoptera (beetles), family Scarabaeidae (scarab beetles). They undergo complete metamorphosis (egg, larva, pupa, adult). Unlike some insects that have a one-year cycle, many *Phyllophaga* species require a **two- or three-year life cycle** to complete development. This means grub damage may be most intense every three years, and multiple generations can overlap in the soil.
Physical Description
Adult June Bugs are robust, clumsy fliers, 1/2 to 1 inch long.
- **Adult Appearance:** Shiny, reddish-brown or dark brown body with hard wing covers (elytra). They are nocturnal, attracted to bright lights, and tend to blunder into objects.
- **Larvae (White Grubs):** Creamy white, thick, C-shaped larvae with a distinct brown head capsule and six legs near the head. They are found burrowed in the soil, particularly in moist, organic-rich areas.
- **Damage Sign (Key ID):** The lawn develops **irregular brown patches** that often feel spongy or can be **pulled up like a rug** because the roots have been severed. Secondary damage comes from natural predators (skunks, raccoons, birds) digging up the lawn to feed on the grubs.
Distribution and Habitat
June Bugs are native to North America and are widespread. The adult habitat is tree and shrub foliage where they feed and mate. The larval habitat is the top 2 to 6 inches of moist soil, especially dense, well-irrigated turf, where they feed on roots. Grubs move deeper into the soil to overwinter.
Behavior and Conflict
Adult feeding causes minimal damage, but the white grub stage is highly destructive.
- **Larval Feeding:** Grubs feed on the roots of turfgrass from late summer through the following spring. Damage is most visible in **late summer/early fall** when the larvae are large and actively feeding, and in **early spring** before they pupate.
- **Attraction to Moisture:** Females prefer to lay eggs in short, moist, healthy turf, often leading to heavy infestations in well-maintained lawns.
- **Life Cycle Length:** Because their cycle can last up to three years, infestations can be persistent and difficult to eradicate quickly.
- **Nuisance:** Adults are a minor nuisance, buzzing loudly and hitting windows when attracted to light at night.
Management and Prevention
Effective control requires targeting the small, newly hatched larvae, ideally in late summer.
- Maintain a deep, healthy root system by watering deeply and infrequently, and mowing at a taller height (3 to 4 inches) to make the lawn more resilient.
- Replace porch lights with yellow or sodium vapor bulbs to reduce the attraction of egg-laying adults.
- Apply **Beneficial Nematodes** (*Heterorhabditis bacteriophora*) in mid-to-late summer when grubs are small and feeding near the surface. The soil must be moist before and after application.
- **Milky Spore** (*Paenibacillus popilliae*) is an effective, long-term biological control primarily used against Japanese beetle grubs, but it may have some effect on other species over several years.
- **Preventive:** Apply a systemic insecticide (containing imidacloprid, clothianidin, or thiamethoxam) in late spring/early summer to prevent newly hatched grubs from causing damage later in the year.
- **Curative:** Use a faster-acting contact insecticide in late summer if high numbers of active grubs are detected, but timing is crucial for success.
Conservation and Research
June Bugs are managed as high-priority turfgrass pests. Research focuses on refining the timing of biological and chemical treatments, particularly the use of nematodes, and developing turf varieties that exhibit greater tolerance or resistance to grub feeding.