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The Autor reports the resnlts of a research carried out between 1980 and 1986 on the Coleop-tera Hydradephaga of the oxbow lakes along the lower course of the river Oglio.15 oxbow lakes,a peat bogand some minor aqnatic environments were studied;55 species were found,among which some of high fau-nistic and zoogeographic significance such as Hygrotus decoratus(Gyll.),Hydroporus dorsalis(F.),Hydropo-rus springeri G.Müller,Agabus undulatus(Schr.),Ilybius subaeneus Er.,Nartus grapei(Gyll.)and Dytiscusmutinensis Peder,2 different biocenoses were identified,one of them typical of oxbow lakes with waterinflow and the other typical of oxbow lakes without water inflow.The fauna of the oxbow lakes along thecourse of the Oglio was compared with the faunas of similar enviromnents of the Po plain,with which itshows a high degree of similarity.From a zoogeographical viewpoint,41 species(74,5% of total)have avery wide distribution;of the remaining 14,10(18,2%)have a european distribution and only 4(7,2%)amediterranean distribution.This is therefore a continental type fauna,similar to the faunas of comparableenvironments in central Europe.
The Autor reports the resnlts of a research carried out between 1980 and 1986 on the Coleop-tera Hydradephaga of the oxbow lakes along the lower course of the river Oglio.15 oxbow lakes, a peat bog and some minor aqnatic environments were studied; 55 species were found, among which some of high fau-nistic and zoogeographic significance such as Hygrotus decoratus (Gyll.), Hydroporus dorsalis (F.), Hydropo-rus springeri G. Müller, Agabus undulatus (Schr.), Ilybius subaeneus Er., Nartus grapei (Gyll.) and Dytiscusmutinensis Peder, one of them different from oxinan lake faunas of similar enviromnents of the Po plain, with which itshows a high degree of similarity .From a zoogeographical viewpoint, 41 species (74,5% of total) have avery wide distribution; of the remaining 14,10 (18,2%) have a european distribution and only 4 (7 , 2%) amediterranean distribution.This is therefore a continental type fauna, similar to the faunas of comparable environments in central Europe.