内蒙古自治区螽亚目(Tettigoniodea,Orthoptera)昆虫区系及地带性分布的研究

STUDIES ON THE FAUNA AND ZONAL DISTRIBUTION OF TETTIGONIODEA (ORTHOPTERA) IN NEI MONGOL AUTONOMOUS REGION

内蒙古自治区目前共知螽亚目昆虫5科、26属、58种(表1)。其中螽斯占总种数的74.2％,蟋蟀占17.3％,其余的占7.5％。其区系组成以古北种为主体,特别是东北中国种、东西伯利亚——蒙古种和欧洲——西伯利亚种是区系组成的核心(表2)。特有种占有一定的比例(10.3％),主要分布于该区东北部的森林草原亚带和西部的荒漠带。中部地区有部分华北种的渗入。在本区东部的草原带中,螽斯亚科昆虫最为丰富;西部的荒漠带中,硕螽亚科昆虫是最突出的代表种,并有中亚种的分布(表4)。从总的种类分布来看,东北部的森林带和草原带的昆虫种类明显比西部荒漠带要丰富,中部的干草原亚带则是上述两者的过渡区域。 文中还根据螽亚目昆虫在不同植被地区的分布情况,采用Sφgrensen系数比较了各地带之间昆虫区系的相似性(表3)。用聚类分析的方法将10个植被地带或亚带划分成6个大的地带区:森林区、草原区、荒漠区、暖温型森林草原区、暖温型典型草原区和暖温型荒漠草原区(图2)。作者详细地叙述了各个地带区中昆虫区系的组成特点和分布规律。并就前人对该区昆虫区划工作提出了若干修订意见。

The present paper is the first report on the fauna and zonal distribution of Tettigoniodea in Nei Mongol Autonomous Region. The study is based on the specimens and materials collected during the years 1983-1988. The collection sites are widely distributed in 70 banners of the autonomous region and cover all the vegetation zones (Fig. 1). A. Bright coniferious forest zone of cold-temperate type. b. Deciduous broad-leaf forest zone of mid-temperate type, C. Forest steppe subzone of mid-temperate type, D. Typical steppe subzone of mid-temperate type, E. Desert steppe subzone of mid-temperate type, F. Forest steppe subzone of warm-temperate type, G. Typical steppe of warm-temperate type, H. Desert steppe subzone of warm-temperate type, Ⅰ. Steppe desert subzone of warm-temperate type, and J. Typical desert subzone of warm-temperate type.2000 specimens of Tettigoniodea are collected, which belong to 5 families, 26 genera and 58 species (Tab. 1). The species of the family Tettigoniidae occupy about 74.2%, those of the fami- ly Gryllidae 17.3%, and the rest 7.5%. Judging from the faunal composition of Tettigoniodea, the palaearctic species are absolutely dominant (80.3%), with species from northeast China, east Siberia and Mongolia as the principle component (Tab. 2). The endemic species (10.3%) are limited to the forest steppe subzone of mid-temperate type in the northeastern part and to the desert zone of the western part. Some of the northeast China species and a few Central Asian species may invade the mid-region steppe zones. Most components of Tettigoniodea species are distributed in the steppe and forest steppe zones of the east and central parts of the region, rather than the western desert zone. The former is fairly rich and abundant in species of the subfamily Tettigoninae, whereas the latter, in the subfamily Deracanthinae (Tab. 4). The typical steppe and desert steppe subzones are intermediate in their respective fauna.Based on the distribution of Tettigoniodea in various vegetation zones, the similarity of faunal composition among the different vegetation zones is interpreted by means of S(?)rensen's index (Tab. 3). As the result of clustering analysis, 10 vegetation zones or subzones are classified into 6 large regions: Forest region, Steppe region, Desert region, Forest steppe region of warm-temperate type, Typical steppe region of warm-temperate type, and Desert steppe region of warm-temperate type (Fig. 2). The characteristics of composition and distribution of Tettigoniodea in all the zonal regions are illustrated in detail. Meanwhile, the geographical division of the insect fauna related to the autonomous region is discussed and reviewed.