June bugs and grubs are common insects in gardens and lawns. Understanding their connection and life stages provides clarity on their presence.
Grubs: The Larval Stage of June Bugs
Grubs are the immature, larval form of June bugs. These larvae are creamy white, C-shaped, with a brown head and three pairs of legs. They range from three-quarters of an inch to two inches long when fully grown. Grubs reside underground, feeding on plant roots, particularly grasses, which causes visible damage.
Adult June bugs are half an inch to one inch long, with a thick, reddish-brown to black body. They are known for clumsy flight and attraction to lights at night.
The June Bug Life Cycle
The June bug life cycle involves four stages: egg, larva, pupa, and adult. Females lay 60 to 75 eggs in the soil, two to five inches deep, during late spring or early summer. Eggs hatch into grubs within two to four weeks.
The grub stage is the longest, lasting one to three years as they feed underground. During this period, grubs grow and molt through multiple instars, with the second year often being the most destructive due to increased feeding needs.
After larval development, grubs pupate, forming a protective casing underground, usually three to six inches deep. This stage lasts about three weeks, as the insect transforms into its adult form. Adult June bugs emerge from the soil in late May or early June. Their adult lifespan of one to two months focuses on mating and egg-laying.
Dealing with June Bugs and Grubs
Damage from June bugs and grubs varies by life stage. Grubs feed on grass roots underground, leading to noticeable patches of dead or yellowing turf. Lawns with significant grub populations may feel spongy, and affected sod can be easily lifted, indicating severe root damage. Adult June bugs feed on tree and shrub foliage, generally causing less severe damage than grubs, often leaving irregular holes in leaves. Grubs also attract animals like moles, skunks, and birds, which dig up lawns for food, further damaging turf.
Management strategies for June bugs and grubs begin with maintaining a healthy lawn, as well-cared-for turf can tolerate minor infestations more effectively. Practices such as proper watering during dry periods and appropriate fertilization contribute to overall plant vigor.
Beneficial nematodes, microscopic roundworms that naturally prey on soil-dwelling insects, offer a non-chemical control option. Heterorhabditis bacteriophora is effective against grubs, entering their bodies and releasing bacteria that eliminate the pest. These nematodes are best applied in late summer or early fall when grubs are small and actively feeding near the surface.
Encouraging natural predators can also assist, though the digging activity of some animals might cause additional lawn disruption. Chemical treatments are available for severe infestations, typically considered after non-chemical approaches have been exhausted.