Pathogens of Ips duplicatus (Coleoptera: Scolytidae) in Three Areas in Central Europe

Jaroslav Holusa ； Jaroslav Weiser ； Karel Drapela

《Acta Protozoologica》 46卷2期 (2007/06) Pp. 157-167

並列摘要

The pathogens of Ips duplicatus were studied in three outbreak areas, i.e. on the border of Bialowieza Primeval Forest (N Poland), in an Armillaria root rot area in the eastern Czech Republic and on the southern edge of the beetle’s range in the Bile Karpaty Mts. and Javorníky Mts. (SE Czech Republic). In all three areas I. duplicatus lives in association with I. typographus. The pathogens found were Chytridiopsis typographi, Larssoniella duplicati, Gregarina typographi, and Pichia sp.
N Poland populations of I. duplicatus, coexisting with I. typographus, had a high endemic level 21.5% and 18.9% of C. typographi in both hosts. Also, I. duplicatus had a rather high infection level of L. duplicati (30%). This pathogen was not present in I. typographus. In the E Czech Republic both bark beetles contained C. typographi in low level, with a maximum of 3% infection in I. duplicatus and 3.6% in I. typographus. We did not find infected beetles of both species at one locality. The average level of infestation of I. duplicatus with L. duplicati was 37.7%.
A bit different situation was found for the most southern range of I. duplicatus (SE Czech Republic), where the insect's distribution mostly depends on spruce forests. Although the infection level of C. typographi is similar to E Czech Republic in both bark beetles, in contrary, only 4.4% beetles were infected by L. duplicati.
Two pathogens, Gregarina typographi, and Pichia sp., appear only as minor admixture, apparently related to local population densities. The infection of I. duplicatus with L. duplicati frequently reaches a high level in both throughout the range of I. duplicatus and the season.

並列關鍵字

Ips duplicatus ； Ips typographus ； Chytridiopsis typographi ； Larssoniella duplicati ； Gregarina typographi ； Pichia sp