Division of Crop Protection, ICAR-grid.418222.fIndian Institute of Horticultural Research, Bengaluru, Karnataka, India.
Microbiol Spectr. 2022 Aug 31;10(4):e0205521. doi: 10.1128/spectrum.02055-21. Epub 2022 Jul 20.
Microbes carve out dwelling niches in unusual environments. Insects, in general, have been hosts to microbes in different ways. Some insects incorporate microbes as endosymbionts that help with metabolic functions, while some vector pathogenic microbes that cause serious plant and animal diseases, including humans. Microbes isolated from insect sources have been beneficial and a huge information repository. The fascinating and evolutionarily successful insect community has survived mass extinctions as a result of their unique biological traits. Wings have been one of the most important factors contributing to the evolutionary success of insects. In the current study, wings of Papilio polytes, a citrus butterfly, were investigated for the presence of ecologically significant microbes within hours of eclosing under aseptic conditions. Scanning electron microscopy (SEM) revealed the presence of bacteria dwelling in crevices created by a specific arrangement of scales on the butterfly wing. A total of 38 bacterial isolates were obtained from the patched wings of the citrus butterfly, and spp. were predominant among them. We probed the occurrence of these microbes to assess their significance to the insect. Many of the isolates displayed antibacterial, antifungal, and biosurfactant properties. Interestingly, one of the isolates displayed entomopathogenic potential toward the notorious agricultural pest mealybug. All the wing isolates were seen to cluster together consistently in a phylogenetic analysis, except for one isolate of Bacillus zhangzhouensis (Papilio polytes isolate [Pp] no. 28), suggesting they are distinct strains. This is a first study reporting the presence of culturable microbes on an unusual ecological niche such as butterfly wings. Our findings also establish that microbes inhabit these niches before the butterfly has contact with the environment. The findings in this report have opened up a new area of research which will not only help understand the microbiome of insect wings but might prove beneficial in other specialized studies.
微生物在不同寻常的环境中开拓栖息小生境。一般来说，昆虫以不同的方式成为微生物的宿主。一些昆虫将微生物作为内共生体纳入体内，以帮助进行代谢功能，而另一些昆虫则携带导致严重植物和动物疾病（包括人类）的病原微生物。从昆虫来源分离出的微生物具有有益作用，是一个巨大的信息库。由于其独特的生物学特征，迷人且在进化上成功的昆虫群落得以在大规模灭绝中幸存下来。翅膀是昆虫进化成功的最重要因素之一。在目前的研究中，在无菌条件下，刚羽化的几个小时内，对柑橘凤蝶（Papilio polytes）的翅膀进行了研究，以调查其是否存在具有生态意义的微生物。扫描电子显微镜（SEM）显示，在蝴蝶翅膀上鳞片的特定排列形成的缝隙中存在细菌。从柑橘凤蝶斑驳的翅膀上共获得 38 个细菌分离株，其中 属最为普遍。我们探查了这些微生物的存在情况，以评估它们对昆虫的重要性。许多分离株表现出抗菌、抗真菌和生物表面活性剂特性。有趣的是，其中一个分离株对臭名昭著的农业害虫粉蚧表现出昆虫病原潜力。除了一个芽孢杆菌属（Zhangzhouensis）的分离株（柑橘凤蝶分离株[Pp] no.28）外，所有翅膀分离株在系统发育分析中始终一致地聚类在一起，这表明它们是不同的菌株。这是首次报道在蝴蝶翅膀等不寻常的生态位存在可培养微生物的研究。我们的研究结果还表明，在蝴蝶与环境接触之前，微生物就已经栖息在这些小生境中。本报告中的发现开辟了一个新的研究领域，不仅有助于了解昆虫翅膀的微生物组，而且可能在其他专门研究中证明是有益的。
