Cryphalus abietis (Ratz.)
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: The southern and central Europe, reaching the United Kingdom, Denmark and the southern Fennoscandia to the north and Morocco to the south.
Host plants: Mainly the Norway spruce, rarely firs, pines and larches.
Morphology: Adults are 1.2-1.8 mm long, similar to Cryphalus piceae, but differ in a size and pattern of setae on elytrae.
Biology: C. abietis is a monogamous species with one generation per year in mountains and two generations in lowlands. Adults are active in April-May and July-August. The nuptial chamber is a few millimeters in size and serves as egg gallery. It is constructed in phloem and upper sapwood. Each female produces 20-100 eggs, laid in clusters. Larval galleries go radially at the beginning, then rather vertically. Larvae or pupae overwinter in galleries, however adults overwinter in the litter or in short tunnels made in branches of old spruces.
Damage: C. abietis attacks mainly weakened trees already infested by other bark beetles. It prefers 20-40 years old trees, but can infest also younger trees and tops or branches of old ones.
Preventive measures: Cutting and removal of weakened trees during winter and early spring. During thinning operations, first of all harvesting of weakened and broken trees is recommended.
Control: Cutting and removal of infested trees during spring and summer. During outbreak the use of trap trees (might be also tops or thick branches) is recommended. They should be prepared in the period from November through April.
 Photo by Robert Dzwonkowski, , Bugwood.org |  Photo by Stanislaw Kinelski, , Bugwood.org |
 Photo by Stanislaw Kinelski, , Bugwood.org |
