Heming B S
Department of Entomology, University of Alberta, Edmonton, Alberta T6G 2E3 Canada.
J Morphol. 1980 Jun;164(3):235-263. doi: 10.1002/jmor.1051640303.
The asymmetric "punch and suck" mouthparts of larval Haplothrips verbasci develop from paired appendages in the late, post-anatrepsis embryo similar to those of other insects. Later, the labrum flexes ventrally over the stomodaeum, the right mandibular appendage degenerates, the maxillary appendages divide into inner (lacinial) and outer (stipital) lobes, and the hypopharynx arises from the venters of the mandibular and maxillary segments. All cephalic segments consolidate anteriorly prior to katatrepsis, their appendages flex ventrally, and the labial appendages fuse medially to form the labium and the primordia of the salivary glands and valve. The left mandible and the lacinial lobes of the maxillae invaginate into the head during and after katatrepsis to form the mandibular and maxillary stylet-secreting organs and these later deposit the cuticle of their respective stylets. Cuticle of the mandibular lever is deposited by labral cells at the apex of the mandibular sheath during and after hatching. That of each maxillary lever is secreted simultaneously into the lumen of a ventrally-directed diverticulum developing from stipital cells at the apex of each maxillary sheath. Shortly after katatrepsis, the maxillary and labial palpi originate respectively from cells in the outer wall of each stipital lobe and at the apex of the labium. Muscles of the mouthparts arise after katatrepsis from cephalic mesoderm and are fully-differentiated before cuticle of the mandibular and maxillary levers has been deposited. Gnathal morphogenesis in embryos of H. verbasci resembles that occurring in bug embryos and provides additional evidence that Thysanoptera and Hemiptera evolved from a common psocopteroid stem species having small, paired, biting and chewing mandibles and well developed lacinial stylets.
幼虫巴氏简蓟马不对称的“刺吸式”口器由后胚胎期晚期的成对附肢发育而来，与其他昆虫的类似。之后，上唇在口道上方腹侧弯曲，右下颌附肢退化，上颌附肢分为内侧（内颚叶）和外侧（柄节）叶，下咽由下颌和上颌节的腹侧部分产生。在胚胎反转前，所有头部节段向前合并，其附肢腹侧弯曲，唇附肢在中线融合形成唇以及唾液腺和瓣膜的原基。在胚胎反转期间及之后，左下颌和上颌的内颚叶内陷进入头部，形成下颌和上颌口针分泌器官，随后这些器官分泌各自口针的角质层。孵化期间及之后，下颌杠杆的角质层由上唇细胞沉积在下颌鞘的顶端。每个上颌杠杆的角质层同时分泌到从每个上颌鞘顶端的柄节细胞发育而来的腹侧憩室腔内。胚胎反转后不久，上颌和唇须分别起源于每个柄节叶外壁的细胞和唇的顶端。口器肌肉在胚胎反转后由头部中胚层产生，在下颌和上颌杠杆的角质层沉积之前就已完全分化。巴氏简蓟马胚胎中的颚形态发生类似于蝽类胚胎中的情况，并提供了额外证据，表明缨翅目和半翅目是从具有小的、成对的、咬嚼式下颌和发育良好的内颚叶口针的共同啮虫类茎物种进化而来的。
