English names: Lodgepole Terminal Weevil
Nordic names: (DK), (FI), (NO), (SE)
Major host plants
Pissodes terminalis is confined to pine trees and attacks mainly lodgepole pine (Pinus contorta).
Mainly trees that are 2-6 m tall are attacked. Feeding punctures by adults can be observed at the base of the current year’s leader, where the female adults lay their eggs. Egg punctures are noticeable due to the presence of resin droplets and necrotic tissue. Initially, larval mines fill with resin, and when needles are elongating the shoots appear purplish in contrast to the pale-green healthy shoots. Repeated attacks can produce multiple leaders and the tree eventually dies.
This species is limited to the western part of North America.
A map can be downloaded from EPPO´s website. See instructions here.
Adults emerge from June to July and they feed on new shoots. Eggs are laid in elongating leaders during summer and they hatch about 2 weeks later. Larvae mine just below the epidermis, destroying the cambial area. During late summer, larvae move to the pith where they overwinter and pupate the following spring.
The natural spread of Pissodes spp. is determined by their flight ability which seems to be up to 100 km. International spread would most probably occur via the shipment of living conifer plants, including Christmas trees. P. terminalis only attacks young growth and is unlikely to be carried by wood.
Detection and inspection
Symptoms are visible when needles are elongating. Look for larvae or pupae in the growing months, and the pupal chambers and adult emergence holes in older attacked stubs. Identification should be made in the laboratory.
Pest status and importance
P. terminalis kills the current year's terminal leader. Its hosts are planted to a certain extent in northern Europe, and it could very probably establish on these species under European conditions.
Source of information
See further information here:
Author: Christiane Scheel and Elise T. Yamamoto Buch
Editor: Dorthe Vestergaard