How the mighty have adapted: Genetic and microbiome changes during laboratory adaptation in the key pest Drosophila suzukii

Adaptation of wild insects to an artificial laboratory environment goes hand in hand with changes in their genetic diversity and symbiotic communities. This can have a profound effect on mass rearing of insects since their biological quality and mating competitiveness might be reduced. Patterns of genetic and symbiotic variation associated with laboratory adaptation vary among species and identifying the agents of selection that drive such patterns can be extremely helpful for pest control programmes. In the present study, we profiled the genetic and symbiotic structure of a wild Drosophila suzukii population and monitored their changes during laboratory adaptation. We employed sixteen microsatellite markers and tracked the fluctuation of their frequencies as domestication was progressing. We also used 16S rRNA sequencing to depict changes in the microbiota structure. Changes in effective and observed allele numbers and heterozygosity became evident from F10, while between F0 and F6 a gradual decline was observed. The microbiota profile of D. suzukii also formed distinct clusters during adaptation as F0 and F1 were differentiated by the rest generations and presented the highest bacterial diversity. Overall, our results showed that laboratory adaptation strongly affects both genetic diversity and bacterial communities of D. suzukii. These results can serve as a reference for the design of an area-wide integrated pest management approach with a Sterile Insect Technique (SIT) component. Rearing productivity, biological quality, and mating competitiveness of a SIT mass-reared strain should be assessed in connection with genetic and symbiotic changes occurring during laboratory adaptation.