Effect of salt marsh drainage on the distribution of Tabanus nigrovittatus (Diptera: Tabanidae)

Immature stages of Tabanus nigrovittatus Macquart inhabit salt marsh sod. A study of the distribution of larvae in relation to the presence or absence of surface water showed that larval densities were higher in salt marsh areas that appeared well drained. Late instars remained above the sod surface more frequently in laboratory conditions mimicking high water-table levels. The development of anaerobic conditions in sod at high water levels probably deterred larvae from burrowing into the sod. Therefore, mosquito control ditches, constructed to augment interstitial drainage inadvertently may have created optimal tabanid larval habitat.