Abstract

Tanytarsus is one of the most abundant and diverse genus of Chironomidae. The delimitation of species is based mainly on features of the male genitalia, supported by pupal diagnostic characters. The main purpose of this study was to review all described Tanytarsus species from the Neotropical Region, including some closely related taxa, in order to contribute to the knowledge of the genus Tanytarsus and to the comprehension of the chironomid systematic. The present dissertation is the first review of the genus Tanytarsus in the Neotropical Region. The revision includes more complete diagnoses, morphological descriptions and diagnostic keys to adult males and pupae, as well as new drawings, more detailed measurements, discussions, notes on distribution and, as far as possible, ecological remarks. Pupae and adult males of Nimbocera patagonica Reiss, 1972, Tanytarsus clivosus Reiss, 1972, Tanytarsus cuieirensis Fittkau & Reiss, 1973, Tanytarsus fastigatus Reiss, 1972, Tanytarsus hamatus Reiss, 1972, Tanytarsus hastatus Sublette & Sasa, 1994, Tanytarsus impar Trivinho-Strixino & Strixino, 2004, Tanytarsus ligulatus Reiss, 1972, Tanytarsus limneticus Sublette, 1964, Tanytarsus magnus Trivinho-Strixino & Strixino, 2004, Tanytarsus marauia Sanseverino, Wiedenbrug & Fittkau, 2002, Tanytarsus pandus Sublette & Sasa, 1994, Tanytarsus revolta Sanseverino, Wiedenbrug & Fittkau, 2002, Tanytarsus rhabdomantis (Trivinho-Strixino & Strixino, 1991), Tanytarsus rinihuensis Reiss, 1972, Tanytarsus waika Sanseverino, Wiedenbrug & Fittkau, 2002, and Tanytarsus xingu Sanseverino, Wiedenbrug & Fittkau, 2002 as well as adult males of Tanytarsus branquini Fittkau & Reiss, 1973, Tanytarsus capitatus Sublette & Sasa, 1994, Tanytarsus cururui Fittkau & Reiss, 1973, Tanytarsus curvicristatus Contreras-Lichtenberg, 1988, Tanytarsus guatemalensis Sublette & Sasa, 1994, Tanytarsus monospinosus Ekrem & Reiss, 1999, Tanytarsus paraligulatus Reiss, 1972, Tanytarsus reissi Paggi, 1992, Tanytarsus riopreto Fittkau & Reiss, 1973, and Tanytarsus tumultuarius Ekrem & Reiss, 1999 are reviewed, redescribed and diagnosed. The pupa of Tanytarsus ligulatus Reiss is described for the first time. One paratype and some specimens of Tanytarsus ligulatus Reiss are slightly different from the holotype, and thus are described separately as Tanytarsus cf. ligulatus. The pupa and adult male of Tanytarsus amazonicus spec. nov. as well as adult males of Tanytarsus digitatus spec. nov., Tanytarsus friburgensis spec. nov., Tanytarsus jacaretingensis spec. nov., Tanytarsus pararinihuensis spec. nov. and Tanytarsus pseudorinihuensis spec. nov. are described as new to science. Caladomyia tuberculata (Reiss, 1972) comb. nov. and Caladomyia alata (Paggi, 1992) comb. nov. were previously placed in Tanytarsus and are transferred to the genus Caladomyia Säwedal, 1981. The pupa and adult male of C. tuberculata as well as the adult male of C. alata are also redescribed and diagnosed, and their placement in the genus Caladomyia is discussed. The Tanytarsus riopreto and Tanytarsus marauia species groups are discussed in the light of imaginal and pupal morphology. The diagnostic characters proposed for each group are discussed and compared among their members. In the past, the immature stages of the Nearctic Tanytarsus limneticus as well as those of the Neotropical Tanytarsus rhabdomantis were erroneous placed in the monotypic genus Nimbocera. A detailed discussion about Nimbocera patagonica, Tanytarsus limneticus and Tanytarsus rhabdomantis is presented, including comparisons of immatures and adults and considerations about the validity of the genus Nimbocera. Some Neotropical species seem to share diagnostic characters with Holarctic Tanytarsus species groups. Thus, some Holarctic groups are also discussed and, as far as possible, figured. It was in the scope of this study the recognition and selection of useful characters in imaginal and immature stages in order to improve the systematic of the genus, to discuss the existence of groups of species, to construct diagnostic keys and to allow systematic predictions. The selected morphological features, measurements and terminology used in the present dissertation are described, commented and figured. Keys to adult males and pupae of the studied species were constructed based on diagnostic characters and are presented here for the first time. Potential morphological characters and their states were tentatively selected and commented in the final discussion of the current dissertation.