Cheliceral chelal design in free-living astigmatid mites (Arthropoda: Acari) is reviewed within a mechanical model. Trophic access (body size and cheliceral reach) and food morsel handling (chelal gape and estimated static adductive crushing force) are morphologically investigated. Forty-seven commonly occurring astigmatid mite species from 20 genera (covering the Acaridae, Aeroglyphidae, Carpoglyphidae, Chortoglyphidae, Glycyphagidae, Lardoglyphidae, Pyroglyphidae, Suidasiidae, and Winterschmidtiidae) are categorised into functional groups using heuristics. Conclusions are confirmed with statistical tests and multivariate morphometrics. Despite these saprophagous acarines in general being simple ‘shrunken/swollen’ versions of each other, clear statistical correlations in the specifics of their mechanical design (cheliceral and chelal scale and general shape) with the type of habitat and food consumed (their ‘biome’) are found. Using multivariate analyses, macro- and microsaprophagous subtypes are delineated. Relative ratios of sizes on their own are not highly informative of adaptive syndromes. Sympatric resource competition is examined. Evidence for a maximum doubling of approximate body volume within nominal taxa is detected but larger mites are not more ‘generalist’ feeding types. Two contrasting types of basic ‘Bauplan’ are found differing in general scale: (i) a large, chunk-crunching, ‘demolition’-feeding omnivore design (comprising 10 macrosaprophagous astigmatid species), and (ii) a small selective picking, squashing/slicing or fragmentary/‘plankton’ feeding design (which may indicate obligate fungivory/microbivory) comprising 20 microsaprophagous acarid-shaped species. Seventeen other species appear to be specialists. Eleven of these are either: small (interstitial/burrowing) omnivores—or a derived form designed for processing large hard food morsels (debris durophagy, typified by the pyroglyphid Dermatophagoides farinae), or a specialist sub-type of particular surface gleaning/scraping fragmentary feeding. Six possible other minor specialist gleaning/scraping fragmentary feeders types each comprising one to two species are described. Details of these astigmatid trophic-processing functional groups need field validation and more corroborative comparative enzymology. Chelal velocity ratio in itself is not highly predictive of habitat but with cheliceral aspect ratio (or chelal adductive force) is indicative of life-style. Herbivores and pest species are typified by a predicted large chelal adductive force. Pest species may be ‘shredders’ derived from protein-seeking necrophages. Carpoglyphus lactis typifies a mite with tweezer-like chelae of very feeble adductive force. It is suggested that possible zoophagy (hypocarnivory) is associated with low chelal adductive force together with a small or large gape depending upon the size of the nematode being consumed. Kuzinia laevis typifies an oophagous durophage. Functional form is correlated with taxonomic position within the Astigmata—pyroglyphids and glycyphagids being distinct from acarids. A synthesis with mesostigmatid and oribatid feeding types is offered together with clarification of terminologies. The chelal lyrifissure in the daintiest chelicerae of these astigmatids is located similar to where the action of the chelal moveable digit folds the cheliceral shaft in uropodoids, suggesting mechanical similarities of function. Acarid astigmatids are trophically structured like microphytophagous/fragmentary feeding oribatids. Some larger astigmatids (Aleuroglyphus ovatus, Kuzinia laevis, Tyroborus lini) approximate, and Neosuidasia sp. matches, the design of macrophytophagous oribatids. Most astigmatid species reviewed appear to be positioned with other oribatid secondary decomposers. Only Dermatophagoides microceras might be a primary decomposer approximating a lichenivorous oribatid (Austrachipteria sp.) in trophic form. Astigmatid differences are consilient with the morphological trend from micro- to macrophytophagy in oribatids. The key competency in these actinotrichid mites is a type of ‘gnathosomisation’ through increased chelal and cheliceral height (i.e., a shape change that adjusts the chelal input effort arm and input adductive force) unrestricted by the dorsal constraint of a mesostigmatid-like gnathotectum. A predictive nomogram for ecologists to use on field samples is included. Future work is proposed in detail.

在一个机械模型中回顾了自由生活的散光螨（Arthropoda：Acari）中的checheleral chelal设计。从形态学上研究了营养通道（身体大小和伸手可及的距离）和食物的处理（chel裂和估计的静态内生压碎力）。将来自20个属的47种常见的象散螨科物种（包括螨科，浮游科，腕突科，嗜铬科，食糖科，Lardoglyphidae，丙酮酸科，Suidasiidae和Winterschmidtiidas）按功能分类。结论已通过统计学检验和多元形态计量学得到证实。尽管这些腐烂的螨类通常互为简单的“缩小/肿胀”形式，在其机械设计的细节（螯鳞和鳞片大小和总体形状）与栖息地类型和所食用食物（它们的“生物组”）之间存在明显的统计相关性。使用多元分析，描述了宏观和微观腐烂亚型。大小的相对比率本身不能很好地说明适应性综合症。审查同伴资源竞争。可以找到在名义分类群内将最大身体体积最大倍增的证据，但螨虫并不是“一般主义者”的喂养方式。发现两种截然不同的基本“ Bauplan”类型在总体规模上有所不同：（i）大型，块状，“拆卸”的杂食动物设计（包含10个大型腐食性象散种），以及（ii）小选择性采摘，挤压/切片或零碎/“浮游生物”喂养设计（可能表示专性真菌/食肉动物），其中包括20种腐食性螨类。其他十七个物种似乎是专家。其中的11种是：小型（间质性/穴居性）杂食性食品-或设计用于加工大型硬质食品的衍生形式（残骸自噬，以焦糖酵母为代表）Dermatophagoides farinae），或特定的表面吸取/刮除碎片进料的专业亚型。描述了六种可能的其他次要专家收集/刮除碎片喂料器，每种类型都包含一到两个物种。这些像散光的营养加工功能组的详细信息需要现场验证和更确证的比较酶学。切面速度比本身并不能很好地预测栖息地，但切面纵横比（或切合力）可指示生活方式。草食动物和害虫种类以预测的大的螯合内吸力为代表。害虫物种可能是源自蛋白质寻找尸体的“切碎机”。乳酸刻纹酵母代表一种螨虫，其镊子状镊子的内力非常微弱。提示可能的吞噬作用（肉食性）与较低的螯合内吸力以及较小或较大的缺口有关，这取决于所消耗线虫的大小。Kuzinia laevis代表了一个硬变态的噬菌体。功能形式与Astigmata中的生物分类位置相关—食虫类和食虫类与螨类不同。提供了具有中鼻咽和奥巴底虫喂养类型的合成以及术语的说明。这些散光虫的最细的螯肉中的螯肉裂口位于与类似的位置，即在唇足类动物中，螯肉可移动指状体的折叠会使吻合干轴折叠，表明功能上的机械相似性。螨类散光虫的营养结构类似于微植食性/片段性喂食原虫。一些较大astigmatids（Aleuroglyphus鲹，Kuzinia蟾，Tyroborus林妮）近似的，并且Neosuidasiasp。比赛，大型植食性oribatids的设计。所审查的大多数散光物种似乎与其他oribatid次级分解器一起定位。只有微角皮病（Dermatophagoides microceras）可能是近似于苔藓样oribatid（Austrachipteria）的主要分解剂。营养性形式。散光虫的差异与oribatids从微观到宏观植物吞噬的形态学趋势一致。这些放线tri螨的关键能力是通过增加螯和螯的高度（即，形状的变化，调节螯的输入力臂和输入的内力）来进行的“食管吻合术”类型，而不受中鼻咽部类似的食管的背侧约束。包括供生态学家在野外采样中使用的预测列线图。提出了进一步的工作。