Bacterial gut microbiomes of aculeate brood parasites overlap with their aculeate hosts’, but have higher diversity and specialization

Abstract

Despite growing interest in gut microbiomes of aculeate Hymenoptera, research so far focused on social bees, wasps and ants, whereas non-social taxa and their brood parasites have not received much attention. Brood parasitism however allows to distinguish between microbiome components horizontally transmitted by spill-over from the host with such inherited through vertical transmission by mothers. Here, we studied the bacterial gut microbiome of adults in seven aculeate species in four brood parasite-host systems: two bee-mutillid (host-parasitoid) systems, one halictid bee-cuckoo bee system and one wasp-chrysidid cuckoo wasp system. We addressed the following questions: 1) Do closely related species possess a more similar gut microbiome? 2) Do brood parasites share components of the microbiome with their host? 3) Do brood parasites have different diversity and specialization of microbiome communities compared with the hosts? Our results indicate that the bacterial gut microbiome of the studied taxa was species-specific, yet with a limited effect of host phylogenetic relatedness and a major contribution of shared microbes between hosts and parasites. However, contrasting patterns emerged between bee-parasite systems and the wasp-parasite system. We conclude that the gut microbiome in adult brood parasites is largely affected by their host-parasite relationships and the similarity of trophic food sources between hosts and parasites.

An experimental approach towards untangling the role of nature versus nurture in shaping the microbiome of social insects

“…Berasategui et al (2016 18 ) showed that the microbiomes of several distinct species feeding on the same food source (conifer seedlings) were highly similar, suggesting that the environment played a bigger role in determining the gut microbial community. Similar results were found in beetles 19 and among army ants and their associated beetle species 20 , for which foraging habits and habitat structured the microbial communities and even brood parasites 21 . However, a large portion of the early evidence documenting environmental effects on the gut microbiome has been correlative.…”

Aedes albopictus microbiota: Differences between wild and mass-reared immatures do not suggest negative impacts from a diet based on black soldier fly larvae and fish food

“…In particular, the bacterial community occurring in aquatic habitats plays a significant role in shaping the gut microbiota [ 23 ]. Hence, the environment, rather than genetics, shapes the gut microbiota of mosquitoes, as in many other insects that acquire their gut microbiota from the environment [ 24 , 25 ]. Such water-derived microbiota makes crucial the implementation of adequate larval diets in mass-rearing programs.…”

Host avian species and environmental conditions influence the microbial ecology of brood parasitic brown‐headed cowbird nestlings: What rules the roost?

“…), morphological and physiological diversity across avian clades (Kohl, 2012). Brood parasitism models (Ronchetti et al., 2022) simplify some of these complexities and can be a valuable tool for parsing apart genetic and environmental factors and how they influence the community membership and structure of the wild avian microbiome. Further, the nested nature of host–microbe interactions within systems of parasitism present a complex set of challenges and opportunities for understanding factors that influence microbial composition and parasite success (Dheilly et al., 2019).…”

“…Brood parasitism models (Ronchetti et al, 2022) simplify some of these complexities and can be a valuable tool for parsing apart genetic and environmental factors and how they influence the community membership and structure of the wild avian microbiome.…”