Abstract: The structural characteristics of chironomid (Diptera: Chironomidae) c ommunity in Mingzhu Lake of Chongming Island, Shanghai, China were studied from July 2006 to April 2008. A total of eleven chironomid species belonging to 10 ge nera and 3 subfamilies were collected, among which, Propsilocerus akamusi an d Microchironomus sp. were predominant. Based on clustering analysis (CA) and importance value (IV), it was found that the dominant species shifted seasonally, wi th Microchironomus sp. in spring and summer, Tanypus chinensis in autumn, an d P. akamusi in winter. There was a significant seasonal difference in the S hannon-Weaver diversity index (H′) of the chironomid community, with the l owest in summer and higher in the other three seasons. The H′ was significa ntly correlated with species richness (S) and evenness (J), and more strongly go verned by J. The average density and biomass of the chironomid community wer e the highest in winter, with a minimum density in autumn and a lower biomass in the other seasons. Among the three dominant species, P. akamusi and Micro chironomus sp. had more obvious seasonal fluctuations in their population dyna mics than T. chinensis. Based on the bioassessment methods of water quality, e.g., H′ and Hilsenhoff biotic index (BI), the Mingzhu Lake wa s considered to be moderately organically polluted and eutrophicated.

Key words: butterfly, monitoring, Europe, case, proposal.