The genus Titanidiops in South-east Asia (Arachnida: Araneae: Idiopidae)

Five Titanidiops species are described: T. birmanicus Schwendinger & Huber, sp. nov. (a ?) and T. tenuis Schwendinger, sp. nov. (a ?) from Myanmar, T. sayamensis Schwendinger & Hongpadharakiree, sp. nov. (a ?) from Thailand and Myanmar, T. inermis Schwendinger, sp. nov. (a ?) from Thailand, T. insularis Schwendinger, sp. nov. (a ?) from Thailand and Indonesia. A key to the seven Titanidiops species known from South-east Asia is provided. Titanidiops inermis sp. nov. stands out among its congeners: the males lack a mating clasper, and the females have tiny spicules on coxae I-II and an enlarged heel on the retrolateral-distal corner of coxa IV. A close relationship between T. inermis sp. nov. and T. pylorus comb. nov. is inferred. Ten species are transferred to Titanidiops: Idiops bombayensis Siliwal, Molur in Gupta et al., 2013, I. medini Pratihar & Das in Pratihar et al., 2020, I. nilagiri Das & Diksha in Das et al., 2019, I. oriya Siliwal in Gupta et al., 2013, I. pylorus Schwendinger, 1991, I. robustus (Pocock, 1898), I. vankhede Siliwal, Hippargi, Yadav & Kumar, 2020. All other Asian species currently under Idiops Perty, 1833 presumably also belong to Titanidiops Simon, 1903. New localities of T. pylorus comb. nov. in Thailand are reported, and the widely disjunct populations of T. insularis sp. nov. are discussed. For most species treated here information on biology and on morphological variation is provided.