The spatial organization of digestion, which corresponds to the steps by which the ingested food is hydrolyzed in the different regions of the gut, was described in insects from the major insect orders. The pattern of digestion and absorption in the midgut shows a strong phylogenetic influence, modulated by adaptation to particular feeding habits. Based on this, basic digestive patterns were recognized and were proposed to represent the major ancestors from which the different orders evolved. The putative ancestors chosen to represent different points in the evolution from basal Neoptera to more derived orders were: Neoptera, Polyneoptera, Hemiptera, Hymenoptera-Panorpoidea (Diptera-Lepidoptera), Lepidoptera, and Cyclorrhapha. The basic plan of Neoptera was supposed to be alike that of Polyneoptera, which was hypothesized from studies performed in grasshoppers, crickets and from stick insects. For Holometabola, the basic plan was initially proposed from studies carried out in beetles, bees, nematocerous flies, common flies and also from moths. This review updates the physiological data supporting the putative midgut basic patterns by discussing available data on insects pertaining to different taxa and details the evolutionary trends of midgut function among the major insect orders. Furthermore, by using recent genomic and transcriptome data, this review discusses the few insects for which the spatial organization of midgut absorption is known.

中文翻译：

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主要昆虫种群中消化吸收的演变趋势。

消化的空间组织，对应于消化食物在肠道不同区域中被水解的步骤，在主要昆虫种群的昆虫中都有描述。中肠的消化吸收模式表现出强烈的系统发育影响，通过适应特定的饮食习惯进行调节。在此基础上，人们认识了基本的消化模式，并提出了代表不同阶次演变的主要祖先的模式。选择来代表从基础新翅目到更多衍生阶的进化过程中不同点的假定祖先是：新翅目，多翅目，半翅目，膜翅目-Pa翅目（鳞翅目-鳞翅目），鳞翅目和Cyclorrhapha。Neoptera的基本计划应该与Polyneoptera的基本计划相似，这是根据对蚱hopper，和竹节虫进行的研究假设的。对于Holometabola，基本计划最初是根据对甲虫，蜜蜂，线虫蝇，普通蝇以及飞蛾进行的研究提出的。这篇综述通过讨论有关不同分类群的昆虫的可用数据来更新支持假定的中肠基本模式的生理数据，并详细介绍了主要昆虫种群中肠功能的进化趋势。此外，通过使用最新的基因组和转录组数据，本综述讨论了已知中肠吸收的空间组织的几种昆虫。这篇综述通过讨论有关不同分类群的昆虫的可用数据来更新支持假定的中肠基本模式的生理数据，并详细介绍了主要昆虫种群中肠功能的进化趋势。此外，通过使用最新的基因组和转录组数据，本综述讨论了已知中肠吸收的空间组织的几种昆虫。这篇综述通过讨论有关不同分类群的昆虫的可用数据来更新支持假定的中肠基本模式的生理数据，并详细介绍了主要昆虫种群中肠功能的进化趋势。此外，通过使用最新的基因组和转录组数据，本综述讨论了已知中肠吸收的空间组织的几种昆虫。