Changes in the Trichoptera (Insecta) Communities from Corbii Ciungi Complex of Streams and Springs (Romanian Plain) in the Past Half Century

Abstract

Abstract The paper presents a comparative analysis of the present day caddisfly communities structure with that of their previous structure, recorded about 45 years ago in several ecosystems of plain springs in the Romanian Plain, such as Valea Izvorului (Corbi Ciungi), in Motaş et al. (1962). Several structural parameters such as species richness, species diversity (H’), frequency of occurrence and sex ratio of some populations of adult Trichoptera were considered. 41 taxa belonging to nine families of Trichoptera were presently identified in comparison with only 14 taxa (adults and larvae) recorded in Motaş (op. cit.). Out of the 41 taxa, two are recorded for the first time in the Romanian fauna (Hydropsyche contubernalis ssp. iranica and Limnephilus tauricus). Seven out of the 14 taxa recorded by Motaş (op. cit.) disappeared completely from the studied spring ecosystems (Lype reducta, Halesus digitatus, Lithax obscurus, Notidobia ciliaris, Triaenodes bicolor, Adicella syriaca and A. filicornis). The disappearance of the seven species from the studied ecosystems and the occurrence of many species unrecorded by the previous studies which are not characteristic to mountain waters are a clear indication of the deterioration of the quality of those ecosystems, which led to a new structure of Trichoptera communities.