Pathogens of the bark beetle Ips cembrae: microsporidia and gregarines also known from other Ips species

• Published in: Journal of applied entomology (1986) Vol. 137; no. 3; pp. 181 - 187
• Main Authors: Holuša, J., Lukášová, K., Wegensteiner, R., Grodzki, W., Pernek, M., Weiser, J.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-04-2013; Wiley-Blackwell; Wiley Subscription Services, Inc
• Subjects: Biological and medical sciences; Chytridiopsis typographi; Control; Fundamental and applied biological sciences. Psychology; Gregarina typographi; large larch bark beetle; Mattesia schwenkei; Nosema sp; pheromone traps; Phytopathology. Animal pests. Plant and forest protection; Protozoa. Invertebrates; trap trees; Chytridiopsis typographi; pheromone traps; Coleoptera; Insecta; large larch bark beetle; Pheromone; Pest; Arthropoda; Pathogenic; Attractive trap; Nosema sp; Gregarina typographi; Invertebrata; trap trees; Mattesia schwenkei; Semiochemicals
• ISSN: 0931-2048; 1439-0418
• DOI: 10.1111/j.1439-0418.2012.01717.x

The objective of the current study was to identify pathogens of the large larch bark beetle, Ips cembrae, which is a secondary pest that has produced several local outbreaks across Europe in recent years. Beetles were collected from pheromone traps, trap trees and emergence traps (Larix decidua) during 2007 to 2011 at 10 study sites in central Europe. A total of 3379 mature and callow beetles were examined with a light microscope, and only two microsporidian pathogens [Chytridiopsis typographi and a diplokaryotic microsporidium (probably Nosema sp.)] and two gregarines (Gregarina typographi and Mattesia schwenkei) were found. Within the I. cembrae populations, the infection rate for C. typographi ranged from 2 to 58%. Nosema sp. occurred in only two beetles in 2007 (at two study sites). G. typographi was recorded only in Austria and Croatia and only in 1–2% of the beetles in those countries. Mattesia schwenkei was observed solely in Croatia in 0.6% of the beetles in that country. Only one fungal pathogen in the genus Fusarium was found and only in two mature beetles (0.7%) in 2010. The pathogen species found during our study of I. cembrae were very similar to the pathogens previously identified for Ips typographus. No species‐specific pathogen was detected.