Asian Longhorned Beetle Life Cycle
In China, this species may have a one- or two-year life cycle, depending on the geographical region. The egg, larva, or pupa are capable of overwintering in conditions similar to those in North Dakota. Young adults emerge from infested trees in May and can potentially fly several hundred yards to search for a host, though they tend to attack the same tree from which they emerged.
Adults: Adults are active from early summer to mid-fall. They feed on the bark of twigs periodically throughout the mating and egg-laying period. On sunny days, the adult beetles are most active from mid-morning to early-afternoon. They usually rest in the canopy on cloudy days.
Eggs: In preparation for egg-laying, females chew oval grooves in the bark in which they lay one egg about 5-7 mm in length. Sap stains are often associated with fresh egg-laying wounds. On average, each female will live approximately 40 days and during that period will lay about 25-40 eggs. The wounds may occur anywhere on the tree, including branches, trunk and exposed roots. Eggs will hatch in one to two weeks.
Larvae: Young larvae begin feeding in the phloem tissue. As they mature, they migrate into the wood creating tunnels as they feed. These galleries cause tree stress and dieback, and in high densities lead to tree death.
Pupae: Larvae mature into pupae in the galleries before turning into adults in summer. The new adults exit the tree by creating large round exit holes about 10-15 mm in diameter.
(The above life cycle representation was created by Michael Bohne, USDA, Bugwood)