The cavities of bamboos (Poaceae) are used by various animals. Most of the animals access these cavities either by existing cracks or by excavating bamboos with soft walls or small, thin-walled bamboos. Only a few animals excavate into the cavities of large and thick- and hard-walled internodes of mature bamboos. We studied two lizard beetle species (Coleoptera: Erotylidae: Languriinae), Doubledaya ruficollis and Oxylanguria acutipennis, that excavate into large internode cavities of recently dead mature bamboos and have morphological modifications. We observed that females of D. ruficollis used their mandibles to bore oviposition holes on Schizostachyum sp. (mean wall thickness = 3.00 mm) and O. acutipennis did so on Dendrocalamus sp. (3.37 mm) bamboos. Previous studies suggested that the markedly asymmetrical mandibles and needle-like ovipositors of females in the genus Doubledaya are adaptive traits for excavating hard-walled bamboos for oviposition. Therefore, we measured their mandibular lengths and ovipositor lengths. D. ruficollis females had greater asymmetry in the mandibles and shorter and less-sclerotized ovipositors than females of congeners using small bamboos. In contrast, O. acutipennis females had slightly asymmetrical mandibles and elongated, well-sclerotized ovipositors. Oviposition holes of D. ruficollis were cone-shaped (evenly tapering), whereas those of O. acutipennis were funnel-shaped (tube-like at the internal apex). This suggests that D. ruficollis females excavate oviposition holes using the mandibles only, and O. acutipennis females use both the mandibles and ovipositors. These differences suggest different oviposition-associated morphological specialization for using large bamboos: the extremely asymmetrical mandibles in D. ruficollis and elongated, needle-like ovipositors in O. acutipennis.

中文翻译：

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头或尾：在两个蜥蜴甲虫Doubledaya ruficollis和Oxylanguria acutipennis（鞘翅目：Erotylidae：Languriinae）中使用大型竹节间的夸张形态

各种动物都使用竹子（禾本科）的腔。大多数动物通过存在的裂缝或用软壁的竹子或小的薄壁竹子挖出这些洞。只有少数动物会进入成熟的竹子大而厚壁且硬壁节间的腔中。我们研究了两种蜥蜴甲虫（鞘翅目：Erotylidae：Languriinae），Doubledaya ruficollis和Oxylanguria acutipennis，它们被挖掘到最近死亡的成熟竹子的大型节间腔中，并进行了形态学修饰。我们观察到，D。ruficollis的雌性使用下颌骨在Schizostachyum sp。上产卵。（平均壁厚= 3.00毫米）和O. acutipennis在Dendrocalamus sp。上做到了。（3.37毫米）竹子。先前的研究表明，Doubledaya属中雌性的明显不对称的下颌骨和针状产卵器是挖掘硬壁竹子产卵的适应性状。因此，我们测量了它们的下颌长度和产卵器长度。D.鷉的女性，她们的下颌骨不对称更大和更短的和不太硬化的产卵器，比用小竹子同类的女性。相比之下，尖吻鲈女性的下颌骨略微不对称，并有细长，硬化良好的产卵器。的产卵孔D.鷉是锥形（渐缩均匀），而那些O. acutipennis呈漏斗形（内部顶点呈管状）。这表明D. ruficollis雌性仅使用下颌骨挖出产卵孔，而A. acutipennis雌性则同时使用下颌骨和输卵管。这些差异表明不同产卵相关形态专业化使用大竹子：在极不对称的下颚骨D.鷉和细长的，针状在产卵器O. acutipennis。