Plural: vittae.
A broad stripe, most often used while describing longitudinal bands on the thorax but can be used for the abdomen and head, when it mostly will be used to describe a cross-band.
E.g.: "Presutural area of scutum with irregular dark brown vittae on lateral margin -Oestrophasia (Cenosoma) sabroskyi."
Does someone has a scan of Nartshuk E.P. 2003. Key to families of Diptera (Insecta) of the fauna of Russian and adjacent countries. Proceedings of the Zoological Institute Vol. 294: 1-252 for me?