Immature stages of Tabanus conterminus and keys to larvae and pupae of common Tabanidae from United States east coast salt marshes

Examination of immature tabanids collected from salt marshes from New Hampshire to Georgia revealed 3 morphologically distinguishable species of tabanid larvae and pupae. The adult greenhead tabanids reared from larvae and pupae collected in certain New England salt marshes north of Boston are recognizable as Tabanus nigrovittatus. In the salt marsh at Leeds Point, New Jersey, and in southern salt marshes, larvae collected mainly from the muddy banks of ditches and creeks were a larger species, T. conterminus. Mature larvae could be identified with key characters located on anterior and posterior segments. Pupae could be distinguished to species by characters on the frontal plate and the pupal aster. The smallest or early instars continue to be difficult to identify. Larvae and pupae of T. conterminus are described for the first time, and keys are provided to larvae and pupae of the common salt marsh tabanids from the USA Atlantic coast.