Revision of the Termitodesmidae, an almost forgotten obligate termitophilous millipede family (Diplopoda, Glomeridesmida)

Abstract The Glomeridesmida, one of the basal-most orders of chilognath millipedes, are still little-known, with only three described genera and 36 described species. The order is divided into two families, the Glomeridesmidae and the Termitodesmidae, the latter containing Termitodesmus Silvestri 1911, with five described species from Sri Lanka, India and Vietnam. Termitodesmidae have an unusual appearance which is easily distinguishable from any other millipede. The family is the only known millipede family only found as guests of social insects and, despite that, very little known. All species are only known from their first descriptions, dating back to 1911, 1913 and 1938, with no species until now the subject of a redescription. The genus was apparently forgotten by most of the zoological community, with works on social insect guests and termitophilous organisms no longer mentioning the Termitodesmus , despite providing chapters on other millipedes. Fresh samples of Termitodesmus from Malaysia, as well as of T. calvus Attems 1938 from Vietnam, provided the impetus to re-study all available type specimens of the family. As illustrated here, the Termitodesmidae are shown to exhibit several unique morphological characters, potentially as an adaptation to life in insect nests. Four species of Termitodesmus are transferred to Ceylondesmus Verhoeff, 1929: C. escherichi (Silvestri, 1911) comb. nov. , C. fletcheri (Hirst, 1913) comb. nov. , C. lefroyi (Hirst, 1911) comb. nov. and C. calvus (Attems, 1938) comb. nov. and one new species, Ceylondesmus kistneri sp. nov. , is described from Malaysia. Lectotypes were selected for C. escherichi , C. fletcheri , and C. lefroyi (Hirst, 1911). Only a single species, Termitodesmus ceylonicus Silvestri, 1911; remains in the genus Termitodesmus .