Two New Tanytarsus Species (Diptera: Chironomidae) from Brazil,with Reduced Median Volsella

The male adults Tanytarsus monospinosus sp. n. and Tanytarsus tumultuarius sp. n. from Brazil are described as new to science, and the species Tanytarsus abnormis Lehmann is transferred to Neostempellina Reiss. The species share the reduction of the median volsella, a genital feature well developed amongst most species of Tanytarsini. There are no obvious close relatives amongst previously described Tanytarsus species, and a thorough phylogenetic analysis including the immature stages will be necessary. However, because there are large differences between these two new species in most morphological characters, it can be assumed that they are not closely related, and the loss of the median volsella thus is unlikely to be a synapomorphy.