Gut bacterial communities in carabid beetles: host taxonomy, extrinsic factors, and feeding habits

Bacteria in animal guts (= the gut bacterial community, GBC) can be crucial to host survival and physiology. These gut bacteria may aid in digestion, synthesis of nutrients, or protection from pathogens. To fully understand the biology of the host, it is therefore necessary to study their gut bacteria. Ground beetles, or carabids (Coleoptera: Carabidae), are a diverse family of insects with ~40,000 species, 2,700 of which are in North America. Ground beetles commonly use their voracious appetites to feed on many agricultural pests and are found in many different habitats. The diversity of carabids plus the ease with which many of them can be collected allows for an examination of the effects of host taxonomy, extrinsic factors, and feeding habits on the GBC. Few studies have examined how these factors affect GBCs. Here, I characterized the GBC of nine carabid subfamilies, 23 genera, and 47 species from various natural settings. First, I used genetic relatedness of the host at three taxonomic levels to assess how host taxonomy relates to GBC diversity. I then examined how GBC diversity varies across habitat, geographic region, season, or years, as well as feeding habits of cropland carabids in Alberta. The results showed that GBCs can differ depending on all those factors, especially host taxonomy and feeding habit. The diversity among some congeneric carabids was especially distinct. As is consistent with previous studies, the two predominate bacterial phyla were Pseudomonadota and Bacillota. The three most common bacterial genera across carabids studied here were Enterococcus, Gilliamella, and an unidentified member of Yersiniaceae. This study also found evidence of core gut bacteria and endosymbiotic bacteria for some carabid groups examined.

Authors

• Fisher, Bryan S.
• University of Lethbridge. Faculty of Arts and Science

• Carabidae
• Gut bacteria
• Carabid
• Carabids
• Ground beetles
• Microbiome
• Gut microbiome

Identifier

hdl:10133/6915

OAI identifier oai:identifier

oai:opus.uleth.ca:10133/6915