Occurrence of Microsporidium sp. and other pathogens in Ips amitinus (Coleoptera: Curculionidae)
Abstract:
A new microsporidium is reported from the small spruce bark beetle, Ips amitinus: Microsporidium sp. with uninucleate oval spores measuring 3.5 × 2.5 μm; infecting cells of the midgut epithelium, midgut muscles, the fat body, the Malpighian tubules, and the gonads of adult beetles collected in Austria. Seven other pathogens were found in beetles collected from Austria, the Czech Republic, and Finland. Six of them were already known from I. amitinus. Nosema cf. typographi is recorded for the first time in the overwintering generation of I. amitinus from the Czech Republic.
Insights
A novel microsporidium species was identified in the small spruce bark beetle, Ips amitinus. This parasite infects multiple beetle tissues, highlighting new disease dynamics in forest ecosystems.
Area of Science:
- Entomology
- Microbiology
- Forest Pathology
Background:
- The small spruce bark beetle (Ips amitinus) is a significant forest pest.
- Understanding insect pathogens is crucial for forest health management.
- Previous research has identified various pathogens in Ips amitinus populations.
Purpose of the Study:
- To report a new microsporidium species infecting Ips amitinus.
- To document other pathogens found in Ips amitinus from multiple European locations.
- To record the first instance of Nosema cf. typographi in overwintering Ips amitinus.
Main Methods:
- Microscopic examination of infected Ips amitinus beetles.
- Morphological characterization of the new microsporidium.
- Pathogen screening in beetle samples from Austria, Czech Republic, and Finland.
Main Results:
- A new microsporidium species, Microsporidium sp., was identified with uninucleate oval spores (3.5 × 2.5 μm).
- This microsporidium infected midgut epithelium, muscles, fat body, Malpighian tubules, and gonads of adult beetles.
- Seven other pathogens were detected; six were known from I. amitinus, and Nosema cf. typographi was newly recorded in overwintering beetles.
Conclusions:
- A new microsporidium poses a potential threat to Ips amitinus populations.
- The presence of multiple pathogens indicates complex disease interactions within beetle populations.
- Further research is needed to assess the impact of these pathogens on Ips amitinus.
