Elevational effects on insect-associated microbiomes along a tropical elevation gradient in the Peruvian Andes

Pinos, Andrea (2026): Elevational effects on insect-associated microbiomes along a tropical elevation gradient in the Peruvian Andes. Dissertation, LMU München: Faculty of Biology

Abstract

This doctoral thesis investigates the dynamics of gut microbial communities associated with three groups of holometabolous insects: bees (Hymenoptera), dung beetles (Coleoptera), and moths (Lepidoptera), along a tropical elevation gradient in the Peruvian Andes. Utilizing sequencing of the V3’V4 region of the 16S rRNA gene, the study characterizes microbial diversity and examines the influence of host taxonomic identity and environmental conditions on community composition. In bees, significant variability in gut microbiota was observed across different tribes, with elevation demonstrating a pronounced impact on microbial richness and diversity, particularly in bumble bees and stingless bees. Notably, microbial composition shifted in response to environmental changes, indicating a strong correlation between host identity and microbial dynamics. For dung beetles, the research revealed that microbial communities are shaped predominantly by local ecological factors, such as soil moisture and dung beetle abundance. A positive relationship between elevation and microbial diversity was identified, along with increased turnover of microbial taxa at higher elevations, suggesting adaptive strategies to environmental stressors. In moths, the study found that host taxonomic identity is the main factor structuring gut microbial communities along the elevation gradient. As elevation increased, there was a notable rise in microbial turnover, with communities becoming more homogeneous at lower elevations. This indicates that environmental factors filter microbial communities, suggesting that moths are particularly adaptable to changing habitats. This research establishes a foundational understanding of the gut microbiota dynamics in holometabolous insect groups and highlights the complexity of host-microbiome interactions in response to elevation-related environmental changes.

• Item Type: Theses (Dissertation, LMU Munich)
• Subjects: 500 Natural sciences and mathematics; 500 Natural sciences and mathematics > 570 Life sciences
• Faculties: Faculty of Biology
• Language: English
• Date of oral examination: 28. April 2026
• 1. Referee: Keller, Alexander
• Signature of the printed copy: 0001/UMC 32024