# Overwintering Does Not Affect Microbiota Diversity in Halyomorpha halys : Implications for Its Ecology and Management

## TL;DR

This study shows that overwintering does not change the microbiota of Halyomorpha halys, an invasive pest, which has implications for its management and ecology.

## Contribution

The study challenges the assumption that overwintering alters host microbiota and reveals its stability in an invasive insect species.

## Key findings

- Microbiota diversity and composition remain stable in H. halys before and after overwintering.
- Geographically close populations show variation in microbiota, but not due to overwintering.
- Two populations were found to harbor the microsporidian pathogen Nosema maddoxi.

## Abstract

Host‐associated microbial communities play an important role in regulating many aspects of insect biology, but changes in this microbiota during diapause and overwintering are still largely unknown.
Halyomorpha halys
is an invasive agricultural pest characterised by a unique overwintering strategy where individuals aggregate and enter a state of dormancy, making it an excellent model to study the relationship between microbiota and diapause. We investigated the bacterial diversity of wild
H. halys
specimens before and after dormancy using 16S rRNA gene amplicon‐sequencing. We found that microbiota varies between geographically neighbouring sampling locations, but there were no significant differences in microbial diversity or composition between populations sampled before and after diapause, despite stressful overwintering conditions. Such stability may relate to the highly specific taxa that dominate the stinkbug‐associated microbial community. In addition, we did not detect any strong association of stink bugs with phytopathogens, but we found that two populations harboured Nosema maddoxi, a microsporidian pathogen of stink bugs. Our results are relevant to the assessment of accidental spillovers of microorganisms in newly invaded areas and to the implementation of the sterile insect technique based on mass trapping, irradiation, shipping and release after diapause of wild individuals.

We challenged the assumption that overwintering significantly alters host microbiota composition, finding no differences between
Halyomorpha halys
populations sampled before and after overwintering. This microbiota stability underscores its role in the invasive pest's resilience and provides insights for ecological management strategies.