Succession of ambrosia beetle microbial community structure throughout development in field and laboratory galleries

Some fungus farming ambrosia beetles rely on multiple nutritional cultivars (Ascomycota: Ophiostomatales and/or yeasts) that seem to change in relative abundance over time. The succession could benefit beetle hosts by optimal consumption of the substrate and improve the longevity of the nest. However, abundances of fungal symbionts are poorly studied and culture-independent quantification of symbiont communities over time has been applied in only a single species. Here, for the first time, we compared the diversity and succession of both fungal and bacterial communities in ambrosia beetle fungus gardens from field and laboratory nests over time. By amplicon sequencing of probed fungus gardens of both nest types at three development phases we could show an extreme reduction of diversity in both bacterial and fungal symbionts in laboratory nests. Furthermore, we observed a general transition of fungal symbionts during beetle development.