Speer Kelly A, Víquez-R Luis, Frick Winifred F, Ibarra Ana, Simmons Nancy B, Dittmar Katharina, Calderón Ricardo Sánchez, Preciado Raisa, Medellín Rodrigo, Tschapka Marco, Sommer Simone, Perkins Susan L
Department of Biological Sciences Northern Arizona University Flagstaff Arizona USA.
Pathogen and Microbiome Institute Northern Arizona University Flagstaff Arizona USA.
Ecol Evol. 2025 Apr 2;15(4):e71120. doi: 10.1002/ece3.71120. eCollection 2025 Apr.
The microbiome-the community of microorganisms that is associated with an individual animal-has been an important driver of insect biodiversity globally, enabling insects to specialize in narrow, nutrient-deficient diets. The importance of maternally inherited, obligate bacterial endosymbionts in provisioning nutrients missing from these narrow dietary niches has been well studied in insects. However, we know comparatively little about the processes that dictate the composition of non-maternally inherited bacteria in insect microbiomes, despite the importance of these bacteria in insect health, fitness, and vector competence. Here, we used two species of obligate insect ectoparasites of bats, the bat flies (Streblidae) and , to examine whether the microbiome, beyond obligate bacterial endosymbionts, is conserved or variable across geographic space, between ectoparasite species, or covaries with the external microbiome of their bat hosts or the cave environment. Our results indicate that ectoparasite microbiomes are highly conserved and specific to ectoparasite species, despite these species feeding on the blood of the same bat individuals in some cases. In contrast, we found high geographic variation in the fur microbiome of host bats and that the bat fur microbiome mimics the cave microbiomes. This research suggests that there is a constraint on blood-feeding insect ectoparasites to maintain a specific microbiome distinct from their host and the environment, potentially to meet their nutritional needs. Given that many of these bacteria are not known to be maternally inherited, this research lays the foundation for future examinations of how blood-feeding arthropods acquire and maintain bacteria in their microbiomes.
微生物组——与单个动物相关的微生物群落——是全球昆虫生物多样性的重要驱动因素，使昆虫能够适应狭窄、营养缺乏的食物。昆虫母体遗传的专性细菌内共生体在提供这些狭窄食物生态位中缺失的营养方面的重要性已得到充分研究。然而，尽管这些细菌在昆虫健康、适应性和传播能力方面很重要，但我们对决定昆虫微生物组中非母体遗传细菌组成的过程却知之甚少。在这里，我们使用了两种蝙蝠专性昆虫外寄生虫——蝙蝠蝇（蝠蝇科）和蛛蝇，来研究微生物组（不包括专性细菌内共生体）在地理空间、外寄生虫物种之间是否保守或可变，或者是否与其蝙蝠宿主的外部微生物组或洞穴环境共变。我们的结果表明，外寄生虫微生物组高度保守且特定于外寄生虫物种，尽管在某些情况下这些物种以相同蝙蝠个体的血液为食。相比之下，我们发现宿主蝙蝠的皮毛微生物组存在高度的地理变异，并且蝙蝠皮毛微生物组与洞穴微生物组相似。这项研究表明，吸血昆虫外寄生虫在维持与宿主和环境不同的特定微生物组方面存在限制，这可能是为了满足它们的营养需求。鉴于许多这些细菌并非母体遗传，这项研究为未来研究吸血节肢动物如何在其微生物组中获取和维持细菌奠定了基础。
