A review of long-legged flies (Diptera: Dolichopodidae) from Burundi with new records and description of a new species of Hercostomus Loew

A new long-legged fly species, Hercostomus storozhenkoi Grichanov, sp. nov., from the Republic of Burundi, is described and illustrated. The male of the new species is similar to H. enghoffi Grichanov, 1999 and H. selikhovkini Grichanov, 1999, but differs in its smaller size, length ratio and setation of fore tarsomeres and male cercus shape. A list of 17 additional species collected during expeditions to Burundi in 2010, 2024 and 2025 is provided, of which the following 14 are reported from the country for the first time: Acropsilus perminutus (Parent, 1937), Amblypsilopus pallidicornis (Grimshaw, 1901), Apelastoneurus biadimbi (Grichanov, 2004), Asyndetus virgatus Curran, 1926, Chaetogonopteron nectarophagum (Curran, 1924), Chrysosoma snelli Curran, 1927, Chrysotus africanus (Parent, 1934), C. arduus Parent, 1934, C. latealatus Vanschuytbroeck, 1951, Diaphorus rita Curran, 1926, Tachytrechus bracteatus (Wiedemann, 1830), Telmaturgus kwandensis (Grichanov, 2008), Thinophilus indigenus Becker, 1902 and T. splendidus Vanschuytbroeck, 1951.

Thinophilus splendidus is also newly recorded from Tanzania and Uganda. The new species and new records increase the known dolichopodid diversity in Burundi to 51 species. A table summarizing the dolichopodid species collected from Burundi during expeditions in 1948–1953, 2010, 2024 and 2025 is provided.

It is supposed that the real number of Burundian dolichopodid species may reach more than 100 species, based on the faunal richness of adjacent countries.