Wood borer - Pityophthorus pityographus (Ratz.)From: Kolk A., Starzyk J. R., 1996: The Atlas of Forest Insect Pests Occurrence: The European species, which has a widespread distribution in the south-western range of its natural host, Norway spruce (Picea abies). It was also recorded from Asia Minor, the western Africa and the Caucasian Mountains. Host plants: Conifers: firs, spruces, pines, larches, including the Scots pine, white pine, Douglas fir. Recorded on deciduous species like Padus sp., Frangula sp., etc. and mistletoe. Morphology: Bark beetles are 1.2-1.8 mm long, cylindrical, brown. Females have a tuff of yellowish hairs on the frons. Elytral declivity is projected in the middle, with six unclear teeth on each side. Biology: Polygamous species. After overwintering in litter or occasionally in galleries, adults initiate swarming in May and June. The male constructs the nuptial chamber about 1.5 mm deep in the wood and attracts 2 up to 8 females. Females chew egg galleries (in the outer sapwood, up to 1 mm in depth) outward. After mating, females lay eggs in niches cut on both sides of galleries. Larval galleries are very narrow, 0.5-0.8 mm wide, and up to 8 cm long. Oval, 1.5-1.8 mm long pupal chambers are constructed in the upper surface of the wood. After feeding for about 6 weeks, larvae pupate. The first pupae appear in August. The first new adults emerge in late-August, and early in September they leave breeding material and fly to litter for overwintering. This species has one generation per year. Damage: This bark beetle infests young and tops of older trees with the thin bark. It prefers suppressed trees weakened by root fungi. It is common in fir forests. Preventive measures and control: Removal of all woody debris like tops, branches, especially those infested.
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Forest Pests: Insects, Diseases & Other Damage Agents |
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