Neoperla (Plecoptera, Perlidae) Emerging from a Mountain Stream in Central Africa

Study of numerous adults was done for 5 species of Neoperla taken in an emergence trap on the stream Kalengo, Republic of Zaire, over 16 months (table 1). Taxonomic characters are evalutaed considering individual variation and variation between disjunct populations. The assumption by previous authors of only 1 variable species of Neoperla in Africa is refuted. Some bionomic data for the 2 common species in the material are presented. Biomass (dry weight) is 462.4 mg/m2/yr or 12% of total biomass of emerging insects (BOTTGER 1975). Close agreement with figures reported for European streams (ILLIES 1971) may be accidental as biocoenotic structures are very different.