The ALB Life Cycle Page 1 of 2

Egg

Bark of recently cut logs, drying trees, stressedand even healthy trees can serve as egg layingsites. In this photo, the bark was removed in asquare, exposing the single egg. The eggs arerice-like and are found right below the bark. Theoviposition niche can be of variable shape.

Larval Stages

After about two weeks the eggs hatch and theworm-like larvae will feed (tunnel) just beneath thebark for a short time. Then the larvae tunnel to theheartwood in the central portion of the tree andfeed. It is here that they can cause extensivedamage.

Pupal Stage

Toward the end of the larval stage, the insect willexpand its feeding tunnel (so it has more room) andgo into a non-feeding stage. It is then called a pupa.It is during this stage (inside the wood) that ittransforms into the adult that most are familiarwith.

The ALB Life Cycle Page 2 of 2

Adult Stage

Side view of adult Asian longhorned beetle. Thebody of the adult beetle (excluding antenna) is about1 1/4 inches in length, and shiny black with smallwhite markings on its wing coverings. The longantennae are banded in black and white.

Adult beetle and emergence holes on a dead Norwaymaple tree. Note the emergence holes which areabout 7/8" in diameter. The adult beetles are heavy-bodied insects. Although they are capable of flight,they probably will not fly great distances to feed ontree twigs, especially if suitable tree hosts arepresent. Adults can probably be expected to bepresent from late May through October. The adultbeetles will feed on the twig bark of healthy trees.The female beetle chews a small funnel shapeddepression in the tree bark and inserts an egg underthe bark.

Looking face to face with the Asian longhornedbeetle. The adult beetles will feed on the twig bark ofhealthy trees. The adult feeding wounds arepossible sites for the introduction of branchpathogens that can eventually kill branches.