ena-STUDY-DUNDEE-24-08-2018-15:38:44:542-121
Vine weevil adult, Otiorhynchus sulcatus Fabricius (Coleoptera: Curculionidae), associated bacterial microbiota is highly conserved across UK populations growing on strawberry plants (Fragaria x ananassa)
Otiorhynchus sulcatus Fabricius, commonly known as black vine weevil or simply vine weevil, is an important pest of soft fruit and ornamental crops. This species is endemic to temperate areas of Europe but has spread to many other areas over the last century, including North America and Australasia. The ability of vine weevils to adapt to such different environments is difficult to reconcile with the parthenogenetic reproduction strategy, likely underpinning a low genetic diversity. It is therefore tempting to hypothesize that weevil adaptation to different environments is, at least partly, mediated by the microbial communities inhabiting these insects. As a first step towards testing this hypothesis we characterised the composition of the bacterial microbiota retrieved from weevil populations feeding on strawberry plants across 4 locations in the United Kingdom. We performed a 16S rRNA gene Illumina amplicon sequencing approach and we generated 2,886,066 high-quality reads. Ecological indices, namely Chao1 and Shannon, revealed that the populations used for this study harbour a low diversity and uneven bacterial microbiota. Furthermore, ß-diversity analysis failed to identify a clear association between microbiota composition and location. Remarkably, a single Operational Taxonomic Unit (OTU) phylogenetically related to Candidatus Nardonella accounted for 74% of the sequencing reads for all the insects considered. Our results indicate that vine weevil bacterial microbiota resembles other insects as it has low diversity and it is dominated by few individual members. A prediction of this observation is that location per se may not be a determinant of microbiota inhabiting weevil populations. Rather, other or additional selective pressures, such as different host plants vine weevils feed on, ultimately shape the weevil bacterial microbiota.  Our results will serve as a reference framework to investigate other or additional hypotheses aiming at elucidating the weevil's adaptation to the environment.
Otiorhynchus sulcatus Fabricius, commonly known as black vine weevil or simply vine weevil, is an important pest of soft fruit and ornamental crops. This species is endemic to temperate areas of Europe but has spread to many other areas over the last century, including North America and Australasia. The ability of vine weevils to adapt to such different environments is difficult to reconcile with the parthenogenetic reproduction strategy, likely underpinning a low genetic diversity. It is therefore tempting to hypothesize that weevil adaptation to different environments is, at least partly, mediated by the microbial communities inhabiting these insects. As a first step towards testing this hypothesis we characterised the composition of the bacterial microbiota retrieved from weevil populations feeding on strawberry plants across 4 locations in the United Kingdom. We performed a 16S rRNA gene Illumina amplicon sequencing approach and we generated 2,886,066 high-quality reads. Ecological indices, namely Chao1 and Shannon, revealed that the populations used for this study harbour a low diversity and uneven bacterial microbiota. Furthermore, ß-diversity analysis failed to identify a clear association between microbiota composition and location. Remarkably, a single Operational Taxonomic Unit (OTU) phylogenetically related to Candidatus Nardonella accounted for 74% of the sequencing reads for all the insects considered. Our results indicate that vine weevil bacterial microbiota resembles other insects as it has low diversity and it is dominated by few individual members. A prediction of this observation is that location per se may not be a determinant of microbiota inhabiting weevil populations. Rather, other or additional selective pressures, such as different host plants vine weevils feed on, ultimately shape the weevil bacterial microbiota.  Our results will serve as a reference framework to investigate other or additional hypotheses aiming at elucidating the weevil's adaptation to the environment.