Integrated species delimitation and conservation implications of an endangered weevil Pachyrhynchus sonani (Coleoptera: Curculionidae) in Green and Orchid Islands of Taiwan

Oceanic islands are productive habitats for generating new species and high endemism, which is primarily due to their geographical isolation, smaller population sizes and local adaptation. However, the short divergence times and subtle morphological or ecological divergence of insular organisms may obscure species identity, so the cryptic endemism on islands may be underestimated. The endangered weevil Pachyrhynchus sonani Kôno (Coleoptera: Curculionidae: Entiminae: Pachyrhynchini) is endemic to Green Island and Orchid Island of the Taiwan‐Luzon Archipelago and displays widespread variation in coloration and host range, thus raising questions regarding its species boundaries and degree of cryptic diversity. We tested the species boundaries of P. sonani using an integrated approach that combined morphological (body size and shape, genital shape, coloration and cuticular scale), genetic (four genes and restriction site‐associated DNA sequencing, RAD‐seq) and ecological (host range and distribution) diversity. The results indicated that all the morphological datasets for male P. sonani, except for the colour spectrum, reveal overlapping but statistically significant differences between islands. In contrast, the morphology of the female P. sonani showed minimum divergence between island populations. The populations of P. sonani on the two islands were significantly different in their host ranges, and the genetic clustering and phylogenies of P. sonani established two valid evolutionary species. Integrated species delimitation combining morphological, molecular and ecological characters supported two distinct species of P. sonani from Green Island and Orchid Island. The Green Island population was described as P. jitanasaius sp.n. Chen & Lin, and it is recommended that its threatened conservation status be recognized. Our findings suggest that the inter‐island speciation of endemic organisms inhabiting both islands may be more common than previously thought, and they highlight the possibility that the cryptic diversity of small oceanic islands may still be largely underestimated.     

下丘脑外侧区注射TRH对大鼠胃酸分泌的影响

本文采用连续收集胃腔灌流法,观察下丘脑外侧区(LHA)注射促甲状腺激素释放激素(TRH)对大鼠胃酸分泌的影响,并分析TRH在LHA促进胃酸分泌的作用机制。结果表明:(1)LHA注射TRH(1μg)明显地刺激胃酸分泌;(2)预先向LHA注射酚妥拉明(10μg)、美多心安(5μg)及胃泌素抗体1μl(1:640)并不影响TRH的泌酸作用,如预先向LHA注射阿托品(5μg)则可消除TRH的泌酸效应;(3)垂体摘除及肾上腺切除均不影响TRH的泌酸作用;(4)隔下迷走神经切断后,LHA注入TRH的泌酸效应仍然出现,但持续时间显著缩短;腹腔交感神经节摘除后,TRH仍能促进胃酸分泌,但分泌量少而平稳。以上结果提示:LHA是TRH中枢泌酸效应的有关结构之一,其中枢机制是通过胆碱能M受体中介的,腹腔交感神经节和膈下迷走神经是TRH泌酸效应的传出途径。前者引起的泌酸反应出现较早且引起泌酸高峰,但持续时间短;后者则引起低平的持续分泌。     

立枯丝核菌蛋白质电泳图谱研究 Ⅰ.融合群与图谱的相关性

用来自日本和美国的立枯丝核菌8个融合群11个类群代表菌株进行可溶性蛋白质电泳,其结果表明,各融合群及亚群之间电泳图谱有显著差异,而同一类群菌株的电泳图谱则相似。分析来源于华东等地已鉴定的融合类群117个菌株的电泳图谱显示,同一融合群内菌株,虽然采集地区、寄主植物或致病力不同,其蛋白质图谱仍十分相似;而不同融合类群的菌株,即使在同一田块中同一种寄主植物上引起相似病害,其图谱也显示出明显差异。本文就上述可溶性蛋白质图谱显示的结果与其它研究者在血清学、DNA同源性.酯酶等生化水平上对融合群的研究结果进行了比较和探讨。     

陕西省棘蝇属一新种(双翅目:蝇科)

整理近年来采自我国秦岭山区的蝇科标本中,发现棘蝇属Phaonia R.-D.一新种。模式标本保存于沈阳师范学院生物系。     

中国柞蚕幼虫腹足趾钩的研究

趾钩是鳞翅目幼虫分类上常用的特征之一。从本世纪40年代起,神冈等对家蚕幼虫腹足趾钩进行了广泛的研究,中岛(1956)对柞蚕幼虫腹足趾钩有过简短的报告。柞蚕幼虫腹足趾钩不但与地理品种分化有关,而且,由于柞蚕幼虫在野外山林中生活,柞蚕取食等活动,均靠趾钩把握柞枝,趾钩与柞蚕把握力有着密切关系。现将柞蚕幼虫腹足趾钩的形态特征扼要报告如下。     

韦氏鳞(虫八)的精子结构(双尾目)

韦氏鳞(虫八)(Lepidocampa weberi)精子为细长的鞭毛精子,成束排列成精索。顶体由三层结构组成;核圆柱形,接于顶体后;鞭毛轴丝微管式为“9+9+2”,9条副微管排列不整齐,集中于轴丝的一侧;两条细长的线粒体衍生物位于顶体、核与轴丝之间,贯穿于精子中部;精子尾部围有大量片层结构。结果表明韦氏鳞(虫八)精子与康(虫八)精子较为接近,但可能比康(虫八)精子更为特化。