The family Xenasteiidae consists of minute milichiid-like flies (ca.
1.2 to 2.0 mm long) and occurs primarily on islands in the Indo-Pacific
area from Aldabra and the Seychelles to Hawaii. The monotypic genus Tunisimyia Papp occurs only in Tunisia. Hardy (1980a) gave a complete account of all
the Indo-Pacific species and placed the family near Asteiidae. However,
D.K. McAlpine (in litt.) places it near Carnidae and J.F. McAlpine
(in litt.) places it near Anthomyzidae.
The biology of these flies is largely unknown, although all species seem to inhabit the seashore. Papp (1984e) cataloged the Palearctic species and placed his Tunisimyiidae as a junior synonym of this family.
Refs.: Hardy (1980a, key), Papp (1984e, cat. Palearctic spp.).
XENASTEIA Hardy, 1980a: 211. Type species: Xenasteia sabroskyi Hardy, 1980, orig. des.
divergens Hardy, 1980a: 216. Guam; Belau, Micronesia, Northern Marianas.
fijiana Grimaldi, 2009: 51. Fiji.
hardyi Ismay, 2003: 42. Hawaiian Is.
lansburyi Ismay, 2003: 44. PNG (PNG).
palauensis Hardy, 1980a: 218. Belau; ?French Polynesia, Micronesia, ?Pitcairn Is.
sabroskyi Hardy, 1980a: 221. Hawaiian Is.