Weevil-Hylobius piceus
From Bugwoodwiki
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: H. piceus is a holarctic species. It occurs in the central and northern Europe, Siberia and the northern part of North America.
Host plants: It favours larches and Douglas fir, occasionally feeds on the Scots pine and Norway spruce.
Morphology: Adults are 12-16.5 mm long. The body is black with sparse brownish hair. Elytrae are with yellowish spots of dense hair. H. piceus looks like H. abietis, but differs in pronotum and legs. Pronotum is with distinct depressions on the sides of the middle line. Femora of front legs are with a small spine on the lower side. Elytrae are with rows of punctures that are bigger in the distal part. Antennae are twice shorter than the body. Eggs are white, oval, 2 mm long. The larva is white, legless, up to 25 mm long.
Biology: Adults, pupae or larvae overwinter in pupal chambers. Adults are active from May through July. Adults have maturation feeding on the bark of young tree stems. They feed often on stumps or fresh timber. Females deposit single eggs into holes made in the root bark or in the basal area of stumps or trees. Larvae hatch 14-20 days after oviposition. They feed in phloem and later also in sapwood. They chew galleries up to 11 mm in width and 30 cm in length. Larvae are usually located in the basal part of the stem or on roots under the ground causing a wide necrosis and damage of the bark. Pupal chambers of 20x15 mm in size are constructed in the bark or in the wood, the most often in hollows between roots. Adults emerge 14-20 days after pupation through the oval exit hole of about 6-8 mm in length. This species has one generation per year, or if larvae develop on roots - two years.
Damage: H. piceus attacks weakened trees, stumps and windthrows. The major damage is caused on roots that die leading to the death of trees. Maturation feeding of adults is also harmful, particularly for young seedlings in nurseries and forest regenerations.
Preventive measures and control: Debarking of infested wood, especially stumps. Harvesting heavily attacked stumps. Trap logs could be used from May through July.
 Photo by Robert Dzwonkowski, , Bugwood.org |  Photo by Stanislaw Kinelski, , Bugwood.org |
 Photo by Stanislaw Kinelski, , Bugwood.org |  Photo by Stanislaw Kinelski, , Bugwood.org |
 Photo by Stanislaw Kinelski, , Bugwood.org |  Photo by Stanislaw Kinelski, , Bugwood.org |
 Photo by Stanislaw Kinelski, , Bugwood.org |
