COMMUNITY STRUCTURE OF AQUATIC INSECT AND BIOMONITORING OF WATER QUALITY IN JIUHUAHE RIVER
九华河水生昆虫群落结构和水质生物评价价

Benthic aquatic insects were sampled by sweep nets and brushing stones at 5 sites of the tertiary,quarternary and quinary tributaries of the Jiuhuahe River in Anhui province during June, August and October, 1989. Total 6445 in dividuals which belong to 124 species of 86 genera in 49 families under 9 orders of aquatic insect were collected. They can be classified by 41 species of 31 genera in 12 families of Trichoptera, 26 species of 18 genera in 10 families of Ephemeroptera, 16 species of 11 genera in 5 families of coleoptera, 14 species of 14 genera in 7 families of Diptera, 9 species of 9 genera in 4 families of plecoptera, 8 species of 8 genera in 5 families of Odonata, Sspcies of 5 gengra in 4 families of Hemiptera, 3 species of 3 genera in 1 family of Megaroptera, and 2 species of 1 genus in 1 family of Lepidoptera.In the tertiary and quarternaty tributaries, there is a Shannon diversity index more than 4 with a species rechness over 60, indicating that they have an extremely clean water quality. The quinary tributary has a Shannon diversity index over 3 and a species richness of 29,indicating a cleaner water quality. In the tertiary tributary, Trichoptera and Ephemeroptera are dominant with the best biodiversity index (2.58-2.59) at family level, in the quart ernary tributary, Trichoptera, Ephemeroptera and Diptera are dominant with the highest diversity index (5.54), and in the quinary tributary, Ephemeroptera and Diptera are dominant.An preliminary analysis has been also made, based on the concept of "river in continuation", for the community structure and seasonal variation of aquatic insect in various tributaries, and the relation of the predatory function clusters of Trichoptera to the levels of tributary involved.The necessary physical and chemical paramters are provided.