长足大竹象消化道的解剖形态及电镜扫描结构研究

应用体视显微和电镜扫描技术系统地研究了长足大竹象幼虫、成虫消化道的形态结构特征.通过解剖发现,长足大竹象的消化道分前、中、后肠3部分,前肠占比最小,幼虫嗉囊不明显,无成型的前胃与贲门瓣;成虫均具有嗉囊、前胃、贲门瓣,前胃内部由8个"V"型前胃板环状排列成八角星状,前胃板上着生刚毛状角质齿,贲门瓣呈透明圆漏斗状.按外表形态,成虫中肠可分为2段,前段膨大,后段细直,表面均具绒毛;幼虫中肠可分为3段,前段粗大且表面有块状突起,中段细长且表面光滑,后段略粗,表面具绒毛.马氏管着生于中后肠交界处,3根为一束,共6根,幼虫马氏管较成虫粗,后肠占消化道总长的40%～50%左右.

On Anatomical Morphology and Electron Microscope Scanning Structure of Alimentary Canal of Cyrtotrachelus buqueti (Coleoptera: Curculionidae)

The morphological structure characteristics of digestive tract of Cyrtotrachelus buquetiwere studied by stereomicrography and scanning electron microscopy (SEM). The results show that the alimentary canal of C. buqueti was composed of foregut, midgut and hindgut. The length ration of foregut wasthe lowest in whole digestive tract. Larvae crop was not obvious, and without forming proventriculus and cardiac valve. Both male and female adults had crop, proventriculus, and cardiac valve. Inside the proventriculus, there were 8 rows of "V" shaped chitinous plates, and disposed row by row as an eight pointed star look from transaction. Each of proventriculus plate had densely quill-like cutin spicules. The cardiac valve was transparent and round-funnel-shaped. According to the outward appearance, the midgut of adult was composed of inflated anterior midgut and narrow posterior midgut, with rich villus on the surface. While the midgut of larvae, could be divided into three segments:the dilatate anterior midgut with large block protrusions on the surface, the slender and smooth middle midgut, and the thicker posterior midgut with villus. Peritrophic membrane was absent in both of the stages. The hindgut startedfrom the malpighian tubules. 6 malpiphian tubules were arranged in 2 groups, and each group had three tubules. Larvae malpiphian tubules were thicker than adults. The hindgut occupied about 40%-50% of the total length of alimentary canal.