Pissodes terminalis (Curculionidae)

lodgepole pine terminal weevil


Adults:

Pissodes terminalis adult. 5-7 mm long, mottled yellowish brown in colour. Notice the well-developed snout and clubbed antennae, which are characteristic of this family.



Larvae:

Pissodes terminalis larvae feeding in pith; larvae are apodous and typically Curculionid in appearance. Very similar to P. strobi. Larvae make cocoons in the pith of current year's leader.



Damage:

Death of leader caused by Pissodes terminalis larval mining. Egg deposition is on the current year's leader. Young larvae mine individually in the phloem-cambial region in an upwards direction towards the expanding bud. Mature larvae feed and pupate in the pith region. This activity results in the death of the current years' leader, in contrast to P. strobi, which damages two or more years of growth.



Principal Hosts:

Lodgepole pine.

Economic Importance:

Infestation of saplings by P. terminalis results in forking and heavy branching. This leads to a non-merchantable stand. This insect is of concern to foresters in the interior since it thrives on the thicker leaders of trees in well spaced stands.

References and Links:

EAG: 556, 558; FC: 334.

See HForest for the PFC pest leaflet, or JP17.

And, see the BC Forest Practices Code Terminal Weevils Guidebook (1996), which describes the life history, impact, survey methods, and management options of the terminal weevils, Pissodes strobi, the spruce weevil and Pissodes terminalis, the lodgepole terminal weevil, in young stands in BC.

Additional Images:

Infested leader. Current P. terminalis attack. Deformity of bole as a consequence of weevil attack.