Nones Stefano, Simões Fernanda, Trindade Cândida Sofia, Matos José, Sousa Edmundo
Agrarian and Forestry Systems and Vegetal Health Unit, Instituto Nacional de Investigação Agrária e Veterinária (INIAV), Quinta do Marquês, 2780-159 Oeiras, Portugal.
GREEN-IT Bioresources for Sustainability, ITQB NOVA, Quinta do Marquês, 2780-157 Oeiras, Portugal.
Insects. 2021 Sep 29;12(10):881. doi: 10.3390/insects12100881.
The ambrosia beetle Fab. (Coleoptera: Curculionidae) is a major cork oak pest in Portugal. Female and male beetles have different roles in host tree colonization and are both equipped with prothoracic mycangia for fungal transportation. Despite a known beneficial role of bacteria in ambrosia beetles, information on bacterial composition associated with prothoracic mycangia structures is scarce. Bacterial community from mycangia of male and female beetles collected from cork oak galleries was investigated by means of 16S metagenomics. Mycangia anatomical structure was also explored with histological techniques and X-ray computed microtomography to highlight evidence supporting biological sexual dimorphism. A bacterial community with highly diverse bacterial taxa with low abundances at the genus level was revealed. Lactobacillales, , , , and Sphingomonadaceae were significantly more abundant in males, while , Chitinophagaceae, Enterobacteriaceae, Erwiniaceae, Microbacteriaceae, and were more abundant in females. Additionally, a core bacteriome of five genera was shared by both sexes. Histological examination revealed visible connections linking external and internal tissues in females, but none in males. Overall, these results provide the first insights into sexual differentiation for bacteria in a Platypodinae beetle species, identifying key patterns of bacteria distribution in the context of beetle ecology and functional behavior.
食菌小蠹Fab.（鞘翅目：象甲科）是葡萄牙栓皮栎的主要害虫。雌虫和雄虫在寄主树定殖过程中发挥不同作用，且都配备有前胸菌囊用于运输真菌。尽管已知细菌在食菌小蠹中具有有益作用，但关于与前胸菌囊结构相关的细菌组成的信息却很匮乏。通过16S宏基因组学方法研究了从栓皮栎虫道采集的雌虫和雄虫菌囊的细菌群落。还采用组织学技术和X射线计算机断层扫描对菌囊的解剖结构进行了探究，以突出支持生物性二态性的证据。结果揭示了一个细菌分类群高度多样但属水平丰度较低的细菌群落。乳杆菌目、、、和鞘脂单胞菌科在雄虫中显著更为丰富，而、几丁质ophagaceae、肠杆菌科、欧文氏菌科、微杆菌科和在雌虫中更为丰富。此外，两性共有一个由五个属组成的核心细菌组。组织学检查显示雌虫的外部和内部组织之间存在可见连接，而雄虫中则没有。总体而言，这些结果首次深入了解了食菌小蠹亚科甲虫物种中细菌的性别分化，在甲虫生态学和功能行为的背景下确定了细菌分布的关键模式。
