Eastern larch beetle

Latin name: Dendroctonus simplex LeConte
French name: Dendroctone du mélèze
Order: Coleoptera
Family: Curculionidae

Description

Distribution

Canada

Micro-habitat(s)

Trunk

Damage, symptoms and biology

An eastern larch beetle infestation can be recognized by the presence on the trunk of long flows of resin and dark brown boring dust from the galleries excavated by the larvae and adults.

During severe attacks, the numerous galleries excavated under the bark can disrupt sap flow, eventually causing the tree to become desiccated and die within the year.

Adults emerge from the bark in May and bore into the trunk of stressed trees in order to feed and lay eggs. A network of galleries results from the tunnelling that takes place throughout the season. The eastern larch beetle can produce two complete generations every summer.

The beetles overwinter as adults beneath the bark of tamaracks and remain sexually immature until spring.

Life cycle (East of the Rockies)

Life cycle (East of the Rockies)
Stage/Month	J	F	M	A	M	J	J	A	S	O	N	D
Egg
Larva
Pupa
Adult

Other information

A species indigenous to Canada, eastern larch beetles are frequently observed following a larch sawfly (Pristiphora erichsonii (Htg.)) infestation or environmental disturbances.

Portions of a forest stand may die following an eastern larch beetle outbreak. In urban settings, tamaracks that have declining vigour are often subject to severe attacks by this beetle.

Prompt removal of sick and dead trees, along with bark stripping, can help prevent larch beetle populations from increasing.