The Asian Longhorned Beetle is a wood boring insect that is a very destructive pest on a variety of hardwood trees. Females often feed on tree bark, where they also lay eggs. After egg hatch, the larvae bore into the tree and begin to feed on the living tree tissue, before pupating. Damage from larvae feeding can kill trees after several generations.

Asian Longhorned Beetle Life Cycle Stages

Asian Longhorned Beetles usually take one year to complete a generation and they overwinter as larvae in the tree. When temperatures are sufficient, the larvae resume feeding activities spring or late winter. These larvae then pupate and adults emerge in late spring or early summer. Adults feed on bark, before depositing eggs in the soil.

The period of adult emergence is key for insect prevention, both for placing traps and for using insecticides, if necessary. Researchers have created the Asian Longhorned Beetle Adult Emergence Growing Degree Day Model to better predict when the adults will emerge from the soil.

Calculating Growing Degree Day Units

The Asian Longhorned Beetle Emergence Growing Degree Day model uses a lower threshold of 50F and an upper threshold of 95F . It can be calculated with daily high and low temperatures, using the sine model to estimate growing degree day units, or the Pest Prophet app can be used to calculate GDD accumulation from hourly temperature data for a specific field.

Using Jan. 1st as a default “biofix” date, or starting point for accumulation, the overwintered larvae begin pupation at about 533 GDD (F). The first adult emergence occurs at approximately 757 GDD (F), peaking at about 1551 GDD (F). After adults are caught consistently, control measures should be taken.

Source:

This model was developed and tested in Oregon by Len Coop at Integrated Plant Protection Center, Oregon State University with the following primary references:

Smith, M.T., P.C. Tobin, J. Bancroft, G. Li, and R. Gao. 2004. Dispersal and Spatiotemporal dynamics of asian longhorned beetle (Coleoptera: Cerambycidae)in China. Environ. Entomol. 33:435-442.

Keena, M.A. and P.M. Moore. 2010. Effects of temperature on Anoplophora glabripennis (Col.: Cerambycidae) larvae and pupae. Environ. Entomol. 39:1323-1335.