A ditched tidal marsh in New Jersey represented a variety of microhabitats which influenced distribution of tabanid larvae. Population levels of Tabanus nigrovittatus Macquart and Chrysops spp. were highest below mean high-water level on gently sloping banks where cord grass was about 2 feet tall. The striped horse fly, T. lincola F., and T. species 3 (possibly a variety of a known greenhead) occurred mostly at higher soil elevations where short marsh grasses grew. Evidence strongly indicates that females oviposit primarily on vegetation of a certain height and this choice of site influences resulting larval distribution. Unlike T. nigrovittatus, T. lincola breeds primarily near the upland.