Insect Wiki
Beetle grub

A beetle/cicada larva.

The juvenile beetle is called a grub, most grubs spend their lives underground until emerging as an adult, they spend their lives as a pupa and as a juvenile underground only, they feed on small decaying organisms and act as a potentially saprophytic organism.

Life cycle[]

Much like lepidopterans, beetles undergo a complete metamorphosis, the female lays the eggs deep within the roots of a shrub. As the beetle hatches during July or August generally, it will start consuming the potential host plant and continue cause the plant damage and will eventually destroy the plant. Then the grub will pupate by surrounding itself with a sticky glue like substance which hardens around the grub and transforms it into a pupa. The adult beetle which eventually emerge out of the soil and gain the pigmentation as their pigmentation wears off after immediately leaving their pupa.


They tend to generally curl into a "C" shape upon being disturbed by predators, they burrow into the ground througout fall and spend the winter in their nice and cozy home.

Signs of infestation[]

Damaged sections of lawn appear burned and can be lifted with ease; upon doing so the culprits will be exposed. From your lawn, grubs may move into your vegetable garden and proceed to eat roots and bases of plants, especially in early summer. They can cripple or ruin plants without being detected.


Grub problems can be prevented or reduced by keeping your lawn healthy with proper watering and fertilizing. Keep in mind that adult beetles lay their eggs in July and August and prefer moist, lush lawns; keep the lawn on the dry side during this period and mow it high. While your lawn may briefly go dormant without lots of water, its roots won't be damaged Reduce overwintering grubs by removing all old plants and overgrown weeds as you harvest each crop in the fall. Cultivate the bare soil thoroughly to a depth of 6 to 8 inches. 2 to 3 weeks later, cultivate the soil shallowly to a depth of about 2". At this point you can plant a cover crop or lay down 4" to 6" of winter mulch. In early spring, about 2 weeks prior to planting, give the garden another shallow cultivation to about 2". Upon planting, give soil a final cultivation.