Arthropod-associated microorganisms are important because they affect host fitness, protect hosts from pathogens, and influence the host’s ability to vector pathogens. Stored product mites (Astigmata) often establish large populations in various types of food items, damaging the food by direct feeding and introducing contaminants, including their own bodies, allergen-containing feces, and associated microorganisms. Here we access the microbial structure and abundance in rearing diets, eggs, feces fraction, and mite bodies of 16 mite populations belonging to three species (Carpoglyphus lactis, Acarus siro, and Tyrophagus putrescentiae) using quantitative PCR and 16S ribosomal RNA (rRNA) gene amplicon sequencing. The mite microbiomes had a complex structure dominated by the following bacterial taxa (OTUs): (a) intracellular symbionts of the genera Cardinium and Wolbachia in the mite bodies and eggs; (b) putative gut symbionts of the genera Solitalea, Bartonella, and Sodalis abundant in mite bodies and also present in mite feces; (c) feces-associated or environmental bacteria of the genera Bacillus, Staphylococcus, and Kocuria in the diet, mite bodies, and feces. Interestingly and counterintuitively, the differences between microbial communities in various conspecific mite populations were higher than those between different mite species. To explain some of these differences, we hypothesize that the intracellular bacterial symbionts can affect microbiome composition in mite bodies, causing differences between microbial profiles. Microbial profiles differed between various sample types, such as mite eggs, bodies, and the environment (spent growth medium—SPGM). Low bacterial abundances in eggs may result in stochastic effects in parent-offspring microbial transmission, except for the intracellular symbionts. Bacteria in the rearing diet had little effect on the microbial community structure in SPGM and mite bodies. Mite fitness was positively correlated with bacterial abundance in SPGM and negatively correlated with bacterial abundances in mite bodies. Our study demonstrates critical host-microbe interactions, affecting all stages of mite growth and leading to alteration of the environmental microbiome. Correlational evidence based on absolute quantitation of bacterial 16S rRNA gene copies suggests that mite-associated microorganisms are critical for modulating important pest properties of mites by altering population growth.

节肢动物相关的微生物很重要，因为它们影响宿主的健康，保护宿主免受病原体的侵害，并影响宿主病原体的传播能力。储藏的螨虫（Astigmata）通常会在各种类型的食品中建立大量种群，通过直接进食和引入污染物（包括其自身的身体，含过敏原的粪便和相关的微生物）来破坏食品。在这里，我们获得了16种螨虫的饮食结构，卵，粪便部分和螨体的微生物结构和丰度，这些螨虫属于3个物种（Carpoglyphus lactis，Acarus siro和Tyrophagus putrescentiae）），使用定量PCR和16S核糖体RNA（rRNA）基因扩增子测序。螨的微生物群具有复杂的结构，主要由以下细菌类群（OTU）占据：（a）螨体和卵中Cardinium和Wolbachia属的细胞内共生体；（b）Solitalea，Bartonella和Sodalis属的假定肠道共生体，在螨体中丰富，并且还存在于螨粪中；（c）芽孢杆菌属，葡萄球菌属和科库里亚属的粪便相关或环境细菌在饮食，螨虫的身体和粪便中。有趣和违反直觉的是，各种同种螨种群中微生物群落之间的差异高于不同螨物种之间的差异。为了解释其中的一些差异，我们假设细胞内细菌共生体会影响螨体中的微生物组组成，从而导致微生物分布之间的差异。各种样品类型（如螨卵，尸体和环境）（消耗的生长培养基-SPGM）之间的微生物特征有所不同。卵中细菌含量低可能会导致亲代后代微生物传播的随机效应，但胞内共生体除外。饲养饮食中的细菌对SPGM和螨体中微生物群落结构的影响很小。螨的适应度与SPGM中的细菌丰度呈正相关，与螨体中的细菌丰度呈负相关。我们的研究表明关键的宿主-微生物相互作用，影响螨虫生长的所有阶段并导致环境微生物组的改变。基于细菌16S rRNA基因拷贝的绝对定量的相关证据表明，与螨相关的微生物对于通过改变种群生长来调节螨的重要害虫特性至关重要。