Head lice are exclusive human parasitic blood-sucking insects. Distributed worldwide among school-age children, this parasitosis generates scalp irritation and sometimes social prejudice. Understanding how head lice detect and perceive their human hosts is crucial to control transmission. Here, we describe the sensory structures present on the mouthparts of Pediculus humanus capitis and their possible contribution to the feeding decision-making process. On the anterior zone of the clypeus around the haustellum two morphological types of sensilla, invariable in location and number, were identified: fourteen short clypeus bristles (SCB) and six long clypeus bristles (LCB). During feeding these structures contact the host skin but not its blood. Located antero-dorsally on the everted haustellum and between the epipharyngeal teeth, a third sensillar type was identified: about four short peg epipharyngeal (SPE) sensilla. These structures are bathed with the incoming blood, when head lice feed, so may have a gustatory role. In behavioural experiments antennectomy of lice did not interfere with feeding behaviour, suggesting that the sensory structures on the mouthparts could be involved in host assessment.

头虱是人类寄生的独家吸血昆虫。这种寄生虫病分布在世界各地的学龄儿童中，引起头皮刺激，有时甚至引起社会偏见。了解头虱如何检测和感知其人类宿主对于控制传播至关重要。在这里，我们描述了人类Pediculus capus capitis口器上存在的感觉结构及其对喂养决策过程的可能贡献。在腹股沟周围的伞形前区，鉴定出两种形态学类型的感官，位置和数量均不变：十四个短伞形刚毛（SCB）和六个长形伞形刚毛（LCB）。在喂食期间，这些结构接触宿主皮肤，但不接触其血液。位于外翻的子宫上和上咽齿之间的前背，鉴定出第三种感觉层类型：大约四个短钉上咽（SPE）感觉层。当头虱进食时，这些结构充满了进入的血液，因此可能具有味觉作用。在行为实验中，虱子的肛门切除术不会干扰进食行为，这表明口器的感觉结构可能与宿主评估有关。