Shields Vonnie D C
Department of Biology, University of Regina, Regina, Saskatchewan S4S 0A2, Canada.
J Morphol. 1996 Apr;228(1):89-105. doi: 10.1002/(SICI)1097-4687(199604)228:1<89::AID-JMOR7>3.0.CO;2-K.
The external ultrastructure of sensilla on the maxillary galea are investigated in Mamestra configurata and five other lepidopterous larvae using scanning electron microscopy. The galea and lacinia, comprising the mesal lobe of the maxilla, are either completely separate, fused, or incompletely fused in these species. The distal surface of the mesal lobe of all species examined bears two styloconic sensilla, three basiconic sensilla, and three trichoid sensilla, whereas the midventral wall of this lobe bears a campaniform sensillum. The latter sensillum is visible in only three of the six species examined. The styloconic and basiconic sensilla occupy a ventro anterior location, whereas the trichoid sensilla are positioned dorsoposteriorly. Interspecific comparisons of galeal size, as well as sensillar size, shape, and position are made for all species. The styloconic sensilla are the only sensillar type permeable to an aqueous solution of cobalt chloride when viewed by brightfield light microscopy in all species examined. Cobalt ions permeate through the terminal pore of each styloconic peg and percolate through the fenestrated fibrillar pore matrix, located directly below the pore. These ions permeate along the dendritic channel and accumulate in the adjacent sensillar sinus surrounding the peg and/or style by way of a presumably permeable dendritic sheath in all species, but to varying extents. The cuticular sidewall pores surrounding the terminal pore also appear to be permeable to cobalt ions in all the species examined. In most species examined, the styloconic sensilla are only minimally permeable to mercury ions. In these species, mercury ions permeate through the terminal pore, but become trapped within the plug of fenestrated fibrils within it. The sidewall pores are not permeable to mercury ions in any of the species examined. The styloconic sensilla are not permeable to lead ions in M. configurata or Malacosoma lutescens, the only species tested. © 1996 Wiley-Liss, Inc.
利用扫描电子显微镜对甜菜夜蛾及其他五种鳞翅目幼虫下颚外颚叶上的感器外部超微结构进行了研究。在这些物种中，构成上颚内侧叶的外颚叶和内颚叶要么完全分离，要么融合，要么不完全融合。所有被检查物种内侧叶的远表面都有两个栓锥形感器、三个锥形感器和三个毛形感器，而该叶的腹中壁有一个钟形感器。后一种感器仅在六个被检查物种中的三个中可见。栓锥形和锥形感器位于腹前部，而毛形感器位于背后部。对所有物种的外颚叶大小以及感器的大小、形状和位置进行了种间比较。在所有被检查的物种中，通过明场光学显微镜观察时，栓锥形感器是唯一能让氯化钴水溶液渗透的感器类型。钴离子通过每个栓锥形栓的末端孔渗透，并通过位于该孔正下方的多孔纤维状孔基质渗透。在所有物种中，这些离子沿着树突状通道渗透，并通过一个可能具有渗透性的树突状鞘在围绕栓和/或柄的相邻感器窦中积累，但程度不同。在所有被检查的物种中，围绕末端孔的表皮侧壁孔似乎也能让钴离子渗透。在大多数被检查的物种中，栓锥形感器对汞离子的渗透性极低。在这些物种中，汞离子通过末端孔渗透，但被困在其中的多孔纤维栓内。在所检查的任何物种中，侧壁孔都不能让汞离子渗透。在所测试的仅有的两个物种——甜菜夜蛾和黄斑天幕毛虫中，栓锥形感器对铅离子不具有渗透性。© 1996威利 - 利斯公司。
