Large‐scale exploration of relationships between microbial community characteristics and insecticide resistance in three wheat aphid species

Abstract Insect symbionts play an important role in host physiology and biochemistry. The impact of environmental factors on insect microbiomes and the role of symbionts in host resistance to insecticides in large‐scale fields remain unclear. Here, we explore potential relationships between bacterial communities, environmental factors, and insecticide resistance in three significant aphid species: Sitobion avenae , Rhopalosiphum padi , and Metopolophium dirhodum . Our findings indicate that the three aphid species exhibit similar microbial diversity, whereas notable differences in microbial composition exist, along with a decline in microbial community similarity as geographical distance increased. R. padi displayed a simpler microbial network structure compared to S. avenae and M. dirhodum , and most of its network nodes were attributed to Buchnera . Altitude and temperature were identified as crucial factors that affect the diversity and structure of symbionts in the three aphid species. In addition, we also observed that wheat aphid symbionts' diversity, abundance, and network structure relate to insecticide resistance. Environmental factors, particularly altitude and temperature, primarily influence host resistance to insecticides by affecting the abundance of the dominant symbiont ( Buchnera ) and the overall symbiont community. Our study provides a more comprehensive understanding of the interplay between environmental factors, symbiotic bacteria, and insecticide resistance in wheat aphids.