Newly designed primers amplified a 365-bp fragment including the 3′ end of mitochondrial cytochrome b (cyt b). Field collected specimens of the sand fly, Lutzomyia longipalpis (Lutz and Neiva), from two Brazil locations provided test DNA. The primers, based on consensus sequences from a taxonomic spectrum of arthropods, have also amplified DNA successfully from Lutzomyia shannoni Dyar, Lutzomyia cruzi (Mangabeira), and the mosquito Aedes albopictus (Skuse). Single strand conformation polymorphism (SSCP) was used to recognize the presence of L. longipalpis haplotypes; these were verified subsequently by sequencing the polymerase chain reaction products. The sensitivity of SSCP was demonstrated by (1) the detection of single nucleotide differences in SSCP variants and (2) no sequence variation in specimens with the same SSCP mobility. The application of new primers and the SSCP technique provided a valuable addition to available population genetic tools: they increased the efficiency of detection of variability in the cyt b gene and decreased the time required for screening large numbers of specimens to detect nucleotide variation.