Editorial: Coevolution of insect-gut microbiome

Coevolution of insect-gut microbiomeDimijian (2000) stated that "Symbiotic relationships exist everywhere we look; they are beginning to seem like the very essence of biology."To be sure, the involvement of symbiotic associations and symbiogenesis provide profound biological influence.Examples include the emergence of new structures such as from the partnering of algae and fungi (lichens), the bioluminescence provided by Vibrio fisherii to the Hawaiian Bobtail Squid, nitrogen fixation, and the discovery of the photosynthetic Yellow Spotted Salamander.Thus, symbiotic pairings do appear to be an intrinsic driving force contributing to the diversity of life, the successful existence of many species, immune and other physiological processes, and the very essence of biology.When one thinks of successful species on Earth, insects and microorganisms undoubtedly come to mind.The origin of insects appeared approximately 479 million years ago during the Early Ordovician (Misof et al., 2014) and are considered to be the most successful animals, accounting for > 90% of known animals, and whose natural history is endowed on associations both internally and externally with microorganisms (Douglas, 2014).Classic examples include termites and gut cellulolytic bacteria, Sitophilus beetles and their endosymbiont (SOPE, Sitophilus oryzae endosybiont) and flight, leaf-cutting ants and symbiont cultivation, and Wolbachia causing an array of effects such as feminization, parthenogenesis, cytoplasmic incompatibility, and viral defence.More recent examples include the potential role of symbionts in insecticide resistance (i.e., Pietri and Liang, 2018), a Burkholderia sp., ectosymbiont that has been shown to protect Lagria villosa during molting stages (Janke et al., 2022), sleep-promoting effects of human intestinal bacteria provisioned to Drosophila melanogaster (Ko et al., 2023) and Mosquera et al. (2023) who provide data suggesting that the bacterium Elizabethkingia exerts a positive effect on the development and fitness of mosquito larvae.And these are just a few.The earliest fossil evidence for life on Earth is bacterial (Alegado and King, 2014), with indications that bacteria may have been present during the Precambrian (i.e., Astafieva and Rozanov, 2012) much before the origins of animals some 2 billion years thereafter.Bacteria reshaped the planet giving rise to new environments, atmospheres, and climates, shaping Frontiers in Ecology and Evolution frontiersin.