The first Mutillidae collected in Vanuatu, on Espiritu Santo, are described as a new genus and species: Ancistrotilla azurea n. gen., n. sp. This extends the known range of distribution of the family on the Pacific islands. Three further species of Ancistrotilla n. gen., A. bleuensis n. gen., n. sp., A. aenigmatica n. gen., n. sp. and A. nigra n. gen., n. sp., are described from New Caledonia; A. caledonica (André, 1896) n. comb. is redescribed and compared, and a lectotype is designated. Several other Australasian species are transferred to Ancistrotilla n. gen.: A. albocaudata (André, 1898) n. comb., A. calcarina (André, 1898) n. comb., A. carbonaria (Smith, 1855) n. comb., A. fabricii (André, 1898) n. comb., A. senilis (André, 1898) n. comb., A. transiens (André, 1898) n. comb., A. transitoria (André, 1903) n. comb. and A. viridiceps (André, 1895) n. comb. The existence of several additional undescribed species of Ancistrotilla n. gen. in Australia and New Guinea is noted. Ancistrotilla n. gen. is distinguished from other sphaeropthalmine genera particularly by: in the male, the antennal scrobe with transverse carina dorsally and separate lamellate projection dorsolaterally, clypeus with pair of large acute teeth medially on anterior/ventral margin, T1 with narrow pale integumental band posteriorly, parapenial lobe medially curved and hook-like apically, and penis valve with single strong apical tooth; in the female, the antennal scrobe with strong dorsal carina almost reaching eye, mentum convex and glossa short and blunt, T1 with narrow pale integumental band posteriorly, T2 without apical medially oriented pubescence, pygidial plate broad and delimited, and hypopygium strongly bidentate medioapically.
Hymenoptera, Mutillidae, Vanuatu, New Caledonia, Australia, New Guinea, new genus, new species, new combination.