Detection of cryptic species in the Tabanus nigrovittatus (Diptera : Tabanidae) complex in Massachusetts by morphometric and cuticular hydrocarbon analysis

Greenhead flies of the Tabanus nigrovittatus complex from Massachusetts sal t marshes were identified as T. nigrovittatus Macquart and T. conterminus W alker using the morphometric model developed by Sofield et al. Four body me asurements from a total of 5,983 female flies collected over 2 consecutive years yielded canonical scores producing a unimodal rather than the expecte d bimodal distribution. The lack of bimodality indicated that both species were not present at the study site. This was substantiated by cuticular hyd rocarb on (CHC) analysis of a subsample of these specimens. Fifteen, female flies of the Tabanus nigrovittatus complex from the same site were identif ied to species using the Sofield et al. morphometric model and validated us ing CHC analysis, Two individuals of the T. nigrovittatus complex were iden tified incorrectly as T. conterminus by the morphometric model. The tendenc y of this model to incorrectly classify some individuals of T. nigrovittatu s as T. conterminus brings into question the identity of the Walkers syntyp es of T. conterminus. Based on CHC analysis, our study shows that both spec ies coexist within our study area.