Ochieng S A, Hallberg E, Hansson B S
Department of Zoology, University of Lund, S-22362 Lund, Sweden.
Cell Tissue Res. 1998 Mar;291(3):525-36. doi: 10.1007/s004410051022.
The fine structure and distribution of various types of antennal sensilla in three nymphal stages and in adults of both solitary-reared (solitary) and crowd-reared (gregarious) phases of the desert locust, Schistocerca gregaria, were investigated by scanning and transmission electron microscopy. Four types of sensilla were identified: sensilla basiconica, s. trichodea, s. coeloconica and s. chaetica. S. basiconica contain up to 50 sensory neurons, each of which displays massive dendritic branching. The sensillar wall is penetrated by a large number of pores. In contrast, s. trichodea contain one to three sensory neurons that branch to give five or six dendrites in the sensillar lumen; the sensillum wall is penetrated by relatively few pores. The s. coeloconica are situated in spherical cuticular pits on the antennal surface. The s. coeloconica are of two types: one type contains one to three sensory neurons with double sensillar walls penetrated by slit-like pores, whereas the second type contains four sensory neurons with non-porous double sensillar walls. The s. chaetica have a flexible socket and a thick non-porous sensillum wall and contain four sensory neurons that send unbranched dendrites to a terminal pore. A fifth sensory neuron of the s. chaetica terminates in a tubular body at the base of the hair. S. basiconica and coeloconica are normally distributed over the entire antennal flagellum, with a concentration in the middle segments; s. trichodea have three areas of concentration on the 5th, 10th and 14th flagellar segments. Sensilla chaetica are most abundant on the terminal segment. Locusts raised in solitary conditions have more olfactory sensilla (s. basiconica and s. coeloconica) than crowd-reared locusts. The difference in sensillar numbers is more evident in adults than in nymphs. These results suggest that differences in the odour-mediated behaviour of nymphs and adults, and between the phases of S. gregaria, may be attributable to differences at the sensory input level.
利用扫描电子显微镜和透射电子显微镜，对沙漠蝗（Schistocerca gregaria）孤养（独居）和群养（群居）阶段的三个若虫期及成虫期各类触角感器的精细结构和分布进行了研究。鉴定出四种类型的感器：锥形感器、毛形感器、腔锥形感器和刺形感器。锥形感器含有多达50个感觉神经元，每个感觉神经元都有大量的树突分支。感器壁上有大量小孔。相比之下，毛形感器含有一到三个感觉神经元，这些神经元分支后在感器腔内形成五到六个树突；感器壁上的小孔相对较少。腔锥形感器位于触角表面的球形角质小窝中。腔锥形感器有两种类型：一种类型含有一到三个感觉神经元，其双感器壁上有狭缝状小孔；另一种类型含有四个感觉神经元，其双感器壁无孔。刺形感器有一个灵活的窝和一个厚的无孔感器壁，含有四个感觉神经元，这些神经元将无分支的树突发送到终端孔。刺形感器的第五个感觉神经元在毛基部的管状体内终止。锥形感器和腔锥形感器通常分布在整个触角鞭节上，中间节段较为密集；毛形感器在鞭节的第5、10和14节段有三个集中区域。刺形感器在末端节段最为丰富。孤养条件下饲养的蝗虫比群养蝗虫有更多的嗅觉感器（锥形感器和腔锥形感器）。感器数量的差异在成虫中比在若虫中更明显。这些结果表明，若虫和成虫以及群居沙漠蝗不同阶段在气味介导行为上的差异可能归因于感觉输入水平的差异。
