Identify the Asian Longhorned Beetle

Asian longhorned beetle is not known to occur in Iowa; however this insect is one that we want to catch early if accidentally introduced. Listed below are the characteristics of the beetle and what to look for.

Eradication attempts and quarantines have been successful regarding this pest, especially when it was found in the beginning stages of infestation. If you live in Iowa and suspect Asian longhorned beetle as a new introduction to your area, please contact us, and we would be happy to take a look.

1.) How to Identify the Adult Beetle


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The complete life cycle from egg to adult may take 1-2 years depending on temperature and climate. In Iowa the life cycle will be about 2 years and there will be considerable overlap between insect stages.

Link - Asian Longhorned Beetle Look-Alikes

The majority of adult beetles appear beginning in the month of May through June, and some may continue to emerge into late summer.


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The adults are stout and handsome looking beetles that are ¾ to 1¼ inches long. They have a jet black body and mottled white spots on the back.

The long antennae are 1½ to 2½ times the body length with distinctive black and white bands on each segment.

The feet have a bluish tinge that is especially more noticeable when beetles first emerge.

The most likely native insect to be confused with ALB would be the pine sawyer beetle. Pine sawyer beetles are smaller in size, lighter in color, and have only faintly discernable white bands on their antennae. To see more Asian longhorned beetle look-alikes, please click here.

1.) How to Identify the Larva or "Grub"


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Larvae excavate trough the tree and compromise the structural integrity causing broken limbs and eventually dead trees. Early stage larvae tunnel through the outer sapwood. As larvae mature, they turn and make long tunnels deeper into the branches and trunk of the host tree.

The larva are legless, a creamy white color, with a brown hardened plate on the first body segment where the mouth parts are located. Only the mouth parts are visible from the larva's head. Larva can reach lengths of 2½ inches.

The most likely native larva that could be confused with ALB larva is the carpenter worm. Carpenter worms are moth caterpillars that borer into many stressed or injured trees. They have legs and a distinct caterpillar head, which is not the case for ALB larva.