IDENTIFICATION AND DISCRIMINATION OF ELECTROGENA SPECIES BY NUMERICAL-METHODS (EPHEMEROPTERA, HEPTAGENIIDAE)

Nine species of Electrogena from thirty-one populations were investiga ted on the basis of five meristic and five ratio characters of the lar vae. The attribution of populations to species was checked by a cluste r analysis based on the generalized distances between pairs. Groups re presenting species were then subjected to a multiple discriminant anal ysis; discriminant functions and loadings were calculated. The correct attribution of individuals to species by the discriminant functions r anged from 97% to 100%. The analysis of discriminant loadings shows wh ich characters contribute more to the discrimination of species. Altho ugh many species could be identified with some confidence by a sequent ial monothetic key based on meristic and qualitative characters, the d iscriminant analysis improves the effectiveness of identification of a ll species.