Termites are dominant organisms of tropical ecosystems. Their success is partly due to the diversity of their feeding substrates, from dead plant tissues to mineralised soils. The Apicotermitinae is one of the richest subfamilies of soil-feeding termites, which are traditionally classified in feeding groups according to anatomical criteria, deemed to the reveal whether species feed on organic-rich layers (group III) or on mineralised soil (group IV). Previous studies based on δ 15 N isotopic values showed that this subfamily's niche covers a broad range along the gradient of humification. We hypothesised that this broad feeding range could be reflected in the crop-gizzard (Cr-Gi) content and volume. We investigated 17 African species distributed between the two feeding groups. Our results showed a variation of Cr-Gi volume and a consistent composition of content among Apicotermitinae species. Some small-bodied species had a very large Cr-Gi volume relative to their size, indicating a difference in foraging behaviour. These species might use this enhanced storage capacity to forage for longer periods of time. Cr-Gi content was dominated by clay (kaolinite) suggesting that a dietary specialisation could be based on the quality of organic compounds from organo-mineral aggregates. Variations in crystalline solids (quartz) between species indicate either differences in the abundance of mineral grains between feeding patches or active discrimination among particles by foragers. The similar composition of Cr-Gi contents in afrotropical Apicotermitinae suggests that the anatomical criteria used to assign species to feeding groups III or IV are not appropriate.

中文翻译：

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afrotropical Apicotermitinae (Blattodea, Termitidae) 之间的作物胼胝含量和体积变化

白蚁是热带生态系统的优势生物。它们的成功部分归功于它们的饲养基质的多样性，从死亡的植物组织到矿化土壤。Apicotermitinae 是食土白蚁中最丰富的亚科之一，传统上根据解剖学标准将其分类为摄食组，被认为可以揭示物种是以富含有机物的层（III 组）还是矿化土壤（IV 组）为食. 先前基于 δ 15 N 同位素值的研究表明，该亚科的生态位沿腐殖化梯度涵盖了广泛的范围。我们假设这种广泛的饲养范围可以反映在作物肫（Cr-Gi）含量和体积上。我们调查了分布在两个饲养组之间的 17 种非洲物种。我们的结果表明，Apicotermitinae 物种之间存在 Cr-Gi 体积的变化和一致的含量组成。一些体型较小的物种相对于它们的大小具有非常大的 Cr-Gi 体积，表明觅食行为存在差异。这些物种可能会利用这种增强的存储能力来进行更长时间的觅食。Cr-Gi 含量以粘土（高岭石）为主，这表明饮食专业化可以基于有机矿物聚集体中有机化合物的质量。物种之间结晶固体（石英）的变化表明饲养斑块之间矿物颗粒丰度的差异或觅食者对颗粒的积极区分。