Forest Pests: Insects, Diseases & Other Damage Agents

Norway spruce weevil - Pissodes harcyniae (Herbst)

From: Kolk A., Starzyk J. R., 1996: The Atlas of Forest Insect Pests
(Atlas skodliwych owadów lesnych) - Multico Warszawa, 705 pages. Original publication in Polish. English translation provided by Dr. Lidia Sukovata and others under agreement with The Polish Forest Research Institute.

Occurrence: The mountain regions of the central and northern Europe, and the Altai Mountains.

Host plants: Mostly the Norway spruce, rarely pines and firs.

Morphology: Beetles are narrow, brownish-black or black, 5-7 mm long. Antennae are attached to the rostrum in the middle of its length. The rostrum is longer than the head and pronotum together. On the pronotum there are rounded dots and two light stripes. Elytrae have two yellowish bands, the first of which is disrupted in the middle. Elytrae have distinct ridges. The larva is up to 10-12 mm long, white, with the yellowish brown head. The pupa is also white.

Biology: Newly formed adults start maturation feeding on spruce stems, making holes in the bark and reaching cambium. Resin oozing from wounds makes the stems white. They look like sprayed with a lime. Adults fly from April through September with a culmination in June and July. Females oviposit in clusters of 1-5 eggs into holes made in the bark. Larval galleries run radially in phloem or sapwood, often crossing each other. The fully developed larva makes the pupal chamber of 7-10 mm in length within bark and wood. It is filled with white fibres. Overwintering occurs in the larval, pupal or imaginal stage. Larvae and pupae overwinter under the bark, however adults do it in soil or litter. Pupation usually occurs after overwintering and lasts about 3 weeks. This species has one generation per year, but in mountains and unfavorable conditions the development might take 2 years.

Damage: P. harcyniae attacks mainly weakened trees. When abundant, it becomes more aggressive and can infest healthy trees. Characteristic "white stems" and fading needles indicate infested trees. This species attacks spruce trees of different age, but prefers 50-100 year old trees weakened by defoliators, pollution or drought.

Preventive and control measures: Cutting and removal of infested trees before new adults emerge. The exposure of trap trees from early-March is recommended. They should be debarked before larvae enter the wood.

Diagram, Adult and galleries, Poland Image by Robert Dzwonkowski	Damage Image by Stanislaw Kinelski
Damage, Pitch flow on spruce bark resulting from adult feeding Image by Stanislaw Kinelski	Adult(s) Image by Stanislaw Kinelski

Galleries, ending in pupal chambers Image by Stanislaw Kinelski

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