Gut Bacterial Communities of

Area of Science:

• Entomology
• Microbiology
• Ecology

Background:

• Dendroctonus bark beetles are major conifer pests globally.
• Their gut bacterial communities are understudied across host ranges.
• Understanding these microbiomes is crucial for pest management.

Purpose of the Study:

• To characterize gut bacterial communities of Dendroctonus valens and D. mexicanus across Mexico.
• To identify core bacteriomes and infer conserved metabolic pathways.
• To assess the influence of host range and geography on gut microbiota.

Main Methods:

• Pyrosequencing of gut bacterial DNA.
• Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) for metabolic pathway inference.
• Beta diversity analysis using UniFrac.

Main Results:

• Gut bacterial diversity varied among beetle populations, primarily due to rare taxa.
• No correlation was found between bacterial community phylogenetic distance and geographic distance.
• Each species had a distinct intraspecific core bacteriome, but shared a common interspecific core (Enterobacter, Pantoea, Providencia, Pseudomonas, Rahnella, Serratia).
• Predicted metabolic pathways were conserved across geographical locations.

Conclusions:

• Dendroctonus bark beetle gut microbiomes exhibit geographical variation but possess conserved metabolic functions.
• Core bacteriomes are species-specific yet share common genera across the Dendroctonus genus.
• Conserved metabolic pathways suggest functional resilience of the bark beetle gut microbiome.