The family Dolichopodidae (Diptera) of the Arabian Peninsula: identification key, an updated list of species and new records from Saudi Arabia

Despite the species richness of Dolichopodidae or long-legged flies world-wide (over 8000 species) and its prominent role as an important and ubiquitous natural enemy of pests in a variety of habitats, only four species have been recorded from Saudi Arabia prior to this study. As part of a study on the biodiversity of Diptera of south-western Saudi Arabia, a survey of the Diptera fauna of Jazan, Abha and Najran was performed from 2012 to 2016 using mainly Malaise traps, sweep nets and light traps. Twenty-one species belonging to seven subfamilies of Dolichopodidae were identified and recorded in this study, 20 species and five subfamilies of these are recorded for the first time from south-western Saudi Arabia. This study increases the total number of dolichopodid species in Saudi Arabia (including previous records) to 25. Twenty-one images are presented. A key to genera and species of the Dolichopodidae of the Arabian Peninsula is provided. A list of all dolichopodid species recorded from Saudi Arabia and the Arabian Peninsula is given. Biological information (if known) and world distribution are included. It seems likely that further species will be discovered with more research involving the use of mass trapping methods.