Ministry of Agriculture

Ambrosia Beetle
Xyloborus dispar (Fabricius)

 

Ambrosia beetle beside tunnel excavated through heartwood of apple branch

Entry holes (note sawdust) of female ambrosia beetles tunneling into apple tree


Life Cycle
: Overwinter as adults in host. Adults appear in April and after mating, tunnel into a host to lay eggs. Larvae are present May-July. New adults remain in host to overwinter. One generation per year.

Monitoring: Tanglefoot or some other sticky material applied to the trunks may trap adults and indicate their presence. Ethanol-baited Lindgren Funnel Traps can also be used to detect adults. Look for small exit or entry holes (2mm).

Hosts: Native and cultivated trees.

Comments: Ambrosia beetles tunnel into heartwood causing brown strips of dead tissue in the cambium and discoloration in the heartwood. This contrasts to shothole borers that feed on the cambium, leaving a network of tunnels under the bark.

Body length: Adult - 3.0mm; Mature larva - 4.0mm

 

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