Comparative analysis of gut symbionts in Tribolium castaneum (Coleoptera: Tenebrionidae) and their dietary substrate, sauce-flavored Daqu

Jun Lü ¹, Shan Xu ¹, Can Teng ¹

⁰School of Food Engineering, Moutai Institute, Renhuai, Guizhou, China.

Frontiers in Insect Science +

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July 17, 2025

View abstract on PubMed

Summary

The red flour beetle selectively consumes specific microbes from sauce-flavored Daqu (SFD). Fungi are acquired through diet, while bacteria are selectively colonized, impacting pest control strategies.

Area Of Science

Microbiology
Entomology
Food Science

Background

Stored sauce-flavored Daqu (SFD) is infested by the red flour beetle (Tribolium castaneum), causing economic losses.
Understanding microbial interactions is crucial for managing this pest in the food industry.

Purpose Of The Study

To analyze the microbial communities in SFD and Tribolium castaneum (adults and larvae).
To investigate the transmission pathways and functional roles of microbes in the insect-food interaction.

Main Methods

16S rDNA and ITS sequencing for bacterial and fungal community analysis.
Bioinformatic analysis to compare microbial compositions and infer functional divergence.

Main Results

Tribolium castaneum guts showed distinct bacterial communities (Bacteroidota, Proteobacteria) compared to SFD (Firmicutes).
Fungal communities were dominated by Aspergillus in both SFD and T. castaneum, with larvae uniquely harboring Lichtheimia.
Dietary transmission was significant for fungi (89-94%) but limited for bacteria (2.8-5%), with functional divergence observed in shared bacterial ASVs.

Conclusions

T. castaneum selectively colonizes SFD bacteria like Bacillus and Oceanobacillus, while proportionally acquiring fungi such as Aspergillus via diet.
Gut microbes may serve as a 'seed bank' or selected symbionts, influencing pest ecology.
Findings offer insights for developing novel, microbially-based pest control strategies against T. castaneum.

Keywords:

16S rDNA ITS Tribolium castaneum gut symbionts sauce-flavored Daqu