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In the years 2005– 2006, in the Karkonoski National Park there were conducted observations on infestation of spruce trees by bark beetles (Col., Curculionidae, Scolytinae). Data on bark beetle species composition and frequency of occurrence of individual species were collected. The data on development phenology of the small spruce bark beetle Ips amitinus in the upper subalpine spruce forest sites (1000– 1250 m a.s.l.) indicated higher frequency of occurrence of this species (26.3%) when compared to the European spruce bark beetle Ips typographus. The study included analyses of population size, density, fecundity and mortality of I. amitinus. The rate of development in I. amitinus in the Karkonosze Mts. is similar to that observed in the Alps. The number of laid eggs observed was low and the reproduction success was very high at minimal mortality. Establishment of feeding galleries and egg laying lasted several weeks and 1/3 of feeding galleries were found in the second series of trap trees.
Using GIS techniques, spruce bark beetle Ips typographus (L.) damage was analysed against distance from the edge of small spruce stands with strict protection regime; for reference damage nearby managed spruce stands was used. Mean volume of spruce timber, harvested with sanitary fellings was significantly higher near spruce stands with strict conservation status (14.7 ±2.1 to 17.0 ±3.8 m3/ha) than in the vicinity of managed control sites (9.9 ±0.4 to 11.5 ±0.8 m3/ha). Under endemic spruce bark beetle population levels strict conservation regime in small areas (forest woodland key habitats of average 3.7 ha size) was found to be Ips typographus hazard for adjacent spruce forests up to 450 m distance.
This study concerns a new neogregarine parasitic in the great spruce bark beetle Dendroctonus micans (Kugelann) (Curculionidae, Scolytinae). The rate of infection was high, reaching 27.3%. There was no difference in the rate of infection of male and female beetles. The life-cycle stages of the pathogen were described by light and electron microscopy. Each gametocyst of the neogregarine included 8–16 actinocephalid oocysts measuring 11.19 ± 0.42 × 4.99 ± 0.25 μm. The described pathogen has the typical characteristics of members of the genus Menzbieria within the order Neogregarinida and it was identified as Menzbieria chalcographi. This is the first record of an infection of D. micans by M. chalcographi. Possibly, this pathogen could be useful for the biological control of this destructive bark beetle.
This study dealt with the species distribution and frequency of ophiostomatoid fungi associated with the bark beetle Ips typographus on Norway spruce and Scots pine in north-eastern Poland. At all locations high spruce bark beetle damage has occurred in 2002-2003. Fungi were isolated from beetles and from brood systems of trees infested by the spruce bark beetle. The ophiostomatoid fungi were represented by 13 species. A similar spectrum of ophiostomatoid fungi as that recorded from Picea abies was associated with I. typographus on Pinus sylvestris trees. The most frequent ophiostomatoid species isolated from beetles, phloem and sapwood of Norway spruce were O. bicolor and O. penicillatum. The frequency of occurrence of ophiostomatoid fungi varied significantly among the examined locations. O. bicolor was the most frequently found species on Scots pine infested by I. typographus. The potential role of ophiostomatoid fungi in the epidemiology of I. typographus is discussed. Additionally, we also recorded how the ophiostomatoid fungi associated with spruce bark beetle could grow into phloem and sapwood of Pinus sylvestris trees.
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