The morphology of adult mouthparts of the leafhoppers Alobaldia tobae, Maiestas dorsalis and Stirellus indrus was studied using a scanning electron microscope. The mouthparts are of the typical piercing–sucking type, similar to mouthparts found in other hemipteran insects, and comprise a three-segmented labium with a deep groove in the anterior side, a stylet fascicle consisting of two mandibular and two maxillary stylets, and a small cone-shaped labrum. The mandibular stylets, located laterad of the maxillary stylets, have sculpturing on their tips. The maxillary stylets are interlocked to form a larger food canal and a smaller salivary canal. Sensilla detected on the three leafhopper species were at different locations on the labium. Three kinds of sensilla were found on the Alobaldia tobae and Maiestas dorsalis labium, including two types of sensilla trichodea (I and II), two types of sensilla basiconica (I and II), and one type of sensilla coeloconica (Sco I). Three kinds of sensilla were found on the Stirellus indrus labium, including three types of sensilla trichodea (I, II and III), two types of sensilla basiconica (I and II), and one type of sensilla coeloconica (Sco I). Among them, sensilla trichodea I are the most abundant on all of three species. This is the first report of sensilla coeloconica (Sco I) and sensilla trichodea III on the mouthparts of Deltocephalinae. Sensilla trichodea I (St I) were also found on the surface of the Stirellus indrus labrum, which is also a first report in the Deltocephalinae. These sensilla may be involved in host recognition and are likely chemo- or mechanosensory, or both. The potential functions of the sensilla are discussed. The morphology of mouthparts and the distribution of sensilla on the labium in Alobaldia tobae, Maiestas dorsalis and Stirellus indrus are discussed with respect to their possible functional significance.

中文翻译：

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Alobaldia tobae、Maiestas dorsalis 和Stirellus indrus（半翅目：蝉科：Deltocephalinae）口器的结构和感受器

使用扫描电子显微镜研究了叶蝉 Alobaldia tobae、Maiestas dorsalis 和 Stirellus indrus 的成虫口器的形态。口器为典型的刺吸式，与其他半翅目昆虫的口器相似，包括一个前侧有深沟的三节唇，一个由两个下颌和两个上颌的管心针组成的管心束，以及一个小锥形盂唇。下颌管心针位于上颌管心针的外侧，尖端有雕刻。上颌管心针互锁形成较大的食道和较小的唾液道。在三种叶蝉物种上检测到的感觉器位于阴唇的不同位置。在 Alobaldia tobae 和 Maiestas dorsalis labium 上发现了三种感觉器，包括两种类型的毛状感受器（I和II），两种类型的基本感受器（I和II）和一种类型的腔感受器（Sco I）。在Stirellus indrus labium上发现了三种感受器，包括三种类型的三节感受器（I、II和III），两种类型的基本感受器（I和II）和一种类型的腔感受器（Sco I）。其中，毛虫感器 I 是三个物种中数量最多的。这是在三角头亚科（Deltocephalinae）口器上发现的腔肠感受器（Sco I）和毛虫感受器 III 的首次报道。在Stirellus indrus labrum 的表面也发现了Sensilla trichodea I（St I），这也是在Deltocephalinae 中的首次报道。这些感觉器可能参与宿主识别，可能是化学或机械感应，或两者兼而有之。讨论了感受器的潜在功能。讨论了 Alobaldia tobae、Maiestas dorsalis 和 Stirellus indrus 口器的形态和感觉器在阴唇上的分布，并讨论了它们可能的功能意义。