Neurobasis

The genus ranges from the island of New Guinea to subtropical China, Indomalaya and the Himalayan region as far as north west Pakistan. It includes nine species in the Oriental region, the remaining four being found in New Guinea. The habitus shown for N. chinensis (Linnaeus) (Fig. 54) and deep cleft prementum (Fig. 28) are both typical for the genus. Larvae, tentatively mentioned by Hagen (1880), were first described in detail for N. chinensis (Needham 1911), and likewise by Kumar (1973) who also illustrated a lateral habitus and briefly discussed behaviour and ecology, which is given in more detail by Kumar & Prasad (1977a). Fraser (1933, p. 8) illustrated the habitus (rather stouter than in reality). Lieftinck (1955) described and illustrated the habitus and structural details of N. florida Hagen as N. chinensis, and the habitus only was shown for N. longipes (Orr & Hämäläinen 2007). Neurobasis chinensis is also depicted on web pages such as (Ng 2024a) and there is at least one photograph of an unidentified New Guinea species in life (Orr & Hämäläinen 2007). For all species known the spidery larvae inhabit open vegetation, leaf packs and root masses in clear streams and clamber around slowly with careful deliberate movements, perhaps ensuring they do not lose their grip in swift flowing water. In some locations N. chinensis is recorded in slower flowing water and artificial drains (Kumar 1973, Kumar & Prasad 1977b) It is not known if there are consistent interspecific differences in the larvae except that N. longipes evidently has slightly longer legs (Orr & Hämäläinen 2007). To settle this point detailed direct comparisons of multiple specimens of all species are needed, but as only a few species occur sympatrically, location is often a reliable guide to species identity, and it may also be possible to identify appropriately preserved specimens by DNA analysis. The subgenus Sinobasis, represented by the poorly known species N. anderssoni in southern China has a heavier build in the adult than subgenus Neurobasis (Orr & Hämäläinen 2007) and it seems likely that its larva would also be distinctive.