A new millipede species of the genus Sechelleptus Mauriès, 1980 is described and illustrated
from Mayotte Island, Indian Ocean. This new species, S. arborivagus sp. nov., found on trees, looks
particularly similar to the sympatric S. variabilis VandenSpiegel & Golovatch, 2007, but is much larger
and has a very different ecological behavior. Phylogenetic analyses based on a concatenated dataset of
the COI and 16S rRNA genes and including nine species of Spirostreptidae (including Sechelleptus,
Doratogonus Attems, 1914, Bicoxidens Attems, 1928 and Spirostreptus Brandt, 1833), strongly support
the monophyly of Sechelleptus. Despite the similarity of their genitalia, the molecular analyses also
reveal a clear-cut genetic divergence between S. arborivagus sp. nov. and S. variabilis (22.55% for
COI and 6.63% for 16SrRNA) and further suggest the presence of a higher diversity within the genus
Sechelleptus on Mayotte.
