Otostigmus gravelyi

Remarks. This species was described on the basis of its holotype alone, a female collected from Parambikulam, Kerala, in 1914. Specimens from the Quilon district in Kerala were subsequently assigned to it by Sureshan et al. (2006). Collections by JJ at the type locality did not produce any specimens that correspond to the holotype with respect to the presence of four apical spines and two strong lateral spines on the coxopleural process, having as many as four spines in the VM and VL rows on the ultimate leg prefemur, and showing a transition from smooth TT 1 – 2 to keeled, tuberculate T 3. We have in fact not identified these character states in specimens of Digitipes from any other locality, apart from the specimens assigned to D. gravelyi by Sureshan et al. (2006). The latter (photographs provided by D. Balan) indicate that these distinctive character states of the holotype are conserved in other specimens, even from other localities. Accordingly we regard these characters as potentially being diagnostic of this species. The otostigmine collected by JJ at the type locality of D. graveleyi is clearly a different species, identified below as Otostigmus ruficeps Pocock, 1890. The male has not been described for “ D. ” gravelyi so its membership in the genus was not solidly established. As noted above under discussion of the genus, some of its characters deviate from very stable conditions shared by the other species of Digitipes. It has 19 – 21 antennal articles, whereas all other Indian species have a conserved number of 17 articles. It has five teeth on each forcipular tooth plate, in contrast to a highly conserved pattern of only four teeth in the other Indian and African species. No Digitipes in India or Africa has dorsal spines accompanying the two apical spines on the coxopleural process, and none has more than a single lateral spine (versus two very strong lateral spines in “ D ”. gravelyi). These character states are, however, present in various species of Otostigmus, and indeed there is little to separate “ D. ” gravelyi from Otostigmus rugulosus Porat, 1876. Because we have no new collections of the species, the possibility of synonymy with O. rugulosus is not followed up here, but the close similarity warrants the reassignment of the species to Otostigmus as the new combination Otostigmus (Otostigmus) gravelyi (Jangi and Dass, 1984).