Regional and interspecific variations in the morphology of insects of the Lutzomyia intermedia complex (Diptera, Psychodidae, Phlebotominae)

Introduction Lutzomyia intermedia a. s. and L. neivai, usually considered a s belonging to just one species, constitute a complex of species. The measu rements of several anatomical structures of specimens of both groups, from Brazil, Paraguay, Argentina and Bolivia Ic ere analysed. Method Thirty-nine structures were measured in specimens of both sexes, usi ng a graduated ocular; analysing comparisons by analyses of variance (ANOVA ). Results A significant deviation in the proportions of females and males sho wing each palpal formula and the influence of the region of origin of the f lies were verified. Labrum and maxilary palps were longer in females and An tennomere III Ir as longer of males. Several significant differences in the measurements of wings ere noted, most of them greater in females. The prop ortion of spermathecae with simple heads vas significantly greater in L. ne ivai than in L. intermedia. Significant differences in the length of genita l pump and filaments between the species were also noted. Discussion The variation in the palpal formulae in both sexes show the risk of the use of this formula for the association between specimens of the tw o sexes. The differences in the lengths of palps and labrum between the sex es could be related to female blood feeding. The possible biological signif icance of the sexual differential relation length/width of wings is comment ed on. The different proportions of females of the two species with each sp ermathecae head shape may help in identification. The differences in the le ngths of genital pumps and filaments and the relation between them could he lp in the identification of males, which is still difficult.