The surf flies of the Mascarene Islands (Diptera: Canacidae: Canacinae), with the description of a new species.

A survey of the surf flies (Canacinae) of the main Mascarene Islands of La Réunion, Mauritius, and Rodrigues was undertaken between 2015 and 2018. It encompassed intertidal material from 38 sampling stations on the islands and included records supplied by Martin J. Ebejer from La Réunion. No specimens of surf flies were collected on Rodrigues Is., which lacks suitable rocky shore habitats. A new species of Isocanace Mathis, 1982, that is deemed closely related to I. briani Mathis, 1982 described from Aldabra Is. and Madagascar, is described and figured from Mauritius (I. mauritiana Munari sp. nov.). Nocticanace mahensis (Lamb, 1912) is also reported from La Réunion and Mauritius and Procanace pninae Mathis Freidberg, 1991 from Mauritius (all representing first records for the islands concerned). The Procanace grisescens species-group is also reported from Mauritius for the first time, representing a first record of this species-group from the Mascarenes. An identification key to Afrotropical species of Isocanace is provided and the distributions of all species are mapped.