Four new species of Blastobasis Zeller, 1855 are described from Thailand: B. tridigitella, B. basipectenella, B. bispinaella, and B. ianella. Photographs of the imagos and illustrations of the male and female genitalia are provided.

Four new species of Calosima Dietz, 1910 (Holcocerini); Calosima albafaciella, C. albafasciata, C. malikuli, and C. moriutii are described from Thailand. Photographs of the imagos and illustrations of the male and female genitalia are provided as available.

Five species of Blastobasis are described: Blastobasis murcyae, B. moffetti, B. christou, B. orladelaneae from New Caledonia and B. lososi from Fiji Islands. These descriptions represent, for the first time, a report of Blastobasinae (Coleophoridae) on these islands. Photographs of the imagos, illustrations of wing venation, male and female genitalia are provided as available.