Damage caused by June beetle larvae often goes unnoticed in the early stages. During the first and second instars, the larvae feed primarily on fine root hairs and organic matter in the soil, causing minimal visible impact to the plant. However, as they progress into the third instar, the larvae begin feeding on larger, structural roots. This more aggressive feeding interferes with the plant's ability to uptake water and nutrients, eventually leading to visible symptoms such as wilting, yellowing, and stunted growth. Over time, heavily infested plants may decline significantly or die, especially under dry conditions where root damage exacerbates water stress.

An additional sign of June beetle larval activity is the presence of disturbed soil caused by wildlife. Animals such as skunks, raccoons, and possums are natural predators of white grubs and will actively dig in lawns, garden beds, or crop fields to feed on them. These animals can cause significant secondary damage by uprooting plants or tearing up turf in their search for the grubs. Their digging often appears as small holes or overturned patches of soil, which may be mistaken for other issues. Frequent nighttime disturbance by these animals is often a strong indicator of a heavy grub infestation beneath the surface.

Adult Phyllophaga beetles, which represent the majority of June beetle species, are typically similar in appearance. They are reddish-brown in color and range in size from approximately 10 to 25 millimeters, depending on the species. The larvae, or white grubs, are also quite uniform in appearance—characterized by a whitish, milky body and a reddish-brown head, usually measuring about 5 to 7 centimeters in length. While their external features offer only subtle distinctions, accurate species identification often requires a close examination of the male genitalia or, in some cases, the arrangement of setae on the final abdominal segment, though the latter method is not reliable for all species.

These beetles have a notably long life cycle, spanning one to three years depending on the species and environmental conditions. The cycle begins when females lay eggs in the soil near plant roots. Larvae hatch and begin feeding through the summer months, then migrate deeper into the soil as temperatures drop in autumn. In colder climates, they overwinter as larvae and resume feeding in the spring. As they mature, they become more destructive to crops, with older larvae causing the most significant root damage. Once fully grown, the larvae create an earthen cell in which they pupate. After a few weeks, adult beetles form but remain underground until conditions—especially temperature and rainfall—are favorable for emergence. Once they surface, the adults mate, and females lay eggs in the soil, continuing the cycle.

Preventing June beetles in turfgrass is particularly challenging because the adult beetles are strong fliers and can arrive from surrounding areas without warning. Even well-maintained lawns and sports fields can become infested, as adult beetles are naturally attracted to healthy, moist turf for egg-laying. Since the eggs are deposited underground, the initial stages of infestation often go unnoticed until larval feeding begins to impact the roots.

Adding to the difficulty, beetles do not remain confined to a single location. They often disperse widely, making it nearly impossible to create a physical barrier against their arrival. Natural surroundings such as woodlands, fields, and even neighboring properties can act as continuous sources of incoming beetles each year. This means that even if one area is treated or maintained to reduce populations, reinfestation from nearby habitats is highly likely, making long-term prevention an ongoing challenge rather than a one-time solution.

Larvanem, which contains entomopathogenic nematodes (Heterorhabditis bacteriophora), is an effective biological control option that can be used as part of a yearly strategy to manage June beetle larvae in turf and soil. These beneficial nematodes actively seek out and infect soil-dwelling larvae, penetrating through natural openings and releasing symbiotic bacteria that quickly kill the host.

Applying Larvanem during the early larval stages—shortly after egg hatch—maximizes effectiveness, as younger larvae are more vulnerable and closer to the surface. Because June beetles have a long, often multi-year life cycle, consistent annual applications are important to break the cycle and reduce population buildup over time.

Larvanem is a natural, residue-free solution that works well in turfgrass, golf courses, and ornamental landscapes, especially when integrated with good irrigation and soil management practices. As the larvae tend to remain hidden underground, Larvanem offers a proactive and environmentally friendly approach to targeting the pest before visible damage becomes apparent.