Distinction of males of the Lutzomyia intermedia (Lutz & Neiva, 1912) species complex by ratios between dimensions and by an artificial neural network (Diptera : Psychodidae, Phlebotominae)

The females of the two species of the Lutzomyia intermedia complex can be e asily distinguished, but the males of each species are quite similar: The r atios between the extra-genital and the genital structures of L. neivai are larger than those of L. intermedia s. s., according to ANOVA. An artificia l neural network was trained with a set of 300 examples, randomly taken fro m a sample of 358 individuals. The input vectors consisted of several ratio s between some structures of each insect. The model was rested on the remai ning 58 insects, 56 of which (96.6%) were correctly identified This ratio o f success can be considered remarkable if one takes into account the diffic ulty of attaining comparable results using traditional statistical techniqu es.