Type species: Molophilus brevipennis Curtis, 1833, by original designation.
Diagnosis. Rostrum short, little developed; meron between mesocoxa and metacoxa extensive, seen from lateral aspect larger than mesocoxa; setae of legs simple; R l longer than 2/3 wing length; Rs ending in cell r 3; R 2+3 and R 4+5 distinct; R 5 not fused with M 1+2; r-m present; CuA 2 and A l not fused distally; a 2 long and wide (modified from Theischinger 1992).
The genus Molophilus includes over 1,000 species, present on all continents except Antarctica. Their diversity is greatest in the Australasian region, with 464 species occurring across Australia, New Caledonia, New Zealand, Papua New Guinea and West Papua (Oosterbroek 2023). Australia boasts more species of Molophilus than any other country or continent with 325 species recorded, including the species newly described here. Except for a single species, M. (Molophilus) flavonotatus Skuse, 1890, which is also known from New Zealand, the Australian species of Molophilus are all endemic.
Theischinger (1992) undertook a comprehensive review of the Australian Molophilus, describing many new species and providing a key to the subgenera and species groups. Following Theischinger’s review additional new species have been described over numerous works (Billingham & Theischinger 2018a, 2018b, 2019a, 2019b; Theischinger 1994, 1996a, 1999, 2000, 2012, 2017).
Molophilus is readily distinguished from other Australian Limoniid genera using the key provided in Theischinger (1996b).