Macropelopia Thienemann, 1916

Silva, Fabio Laurindo Da & Pinho, Luiz Carlos, 2020, Macropelopia (Macropelopia) patagonica, a new Tanypodinae (Diptera: Chironomidae) from the Patagonian Andes, Zootaxa 4731 (4), pp. 574-580 : 575

Genus Macropelopia Thienemann

Macropelopia Thienemann in Thienemann & Kieffer, 1916: 497 ; Fittkau 1962: 102; Roback 1971: 87 (in part); Murray & Fittkau 1989: 61; Niitsuma et al. 2004: 44; Cranston & Epler 2013: 53.

Bethbilbeckia Fittkau & Murray, 1988: 253.

Type species: Isoplastus bimaculatus Kieffer [= Tanypus nebulosus Meigen ] by original designation.

Emended diagnosis. Male adult. Foretibial comb consisting of small spines or long bristles (subgenus Macropelopia ), or absent (subgenus Bethbilbeckia ).

Remarks. Generic diagnoses for the adult male of Macropelopia have been given by Fittkau (1962), Roback (1971), Murray & Fittkau (1989) and Niitsuma et al. (2004). However, these diagnoses should be emended to agree with the Patagonian species described here. Recently, Bethbilbeckia was treated as a subgenus of Macropelopia by Cranston & Epler (2013: 53, see commentary in Silva & Ekrem 2016). The male of Macropelopia s. str. is separable from that of the subgenus Bethbilbeckia by the multiserial temporal setae and the tibial comb on the foreleg. The male of the latter has no tibial comb on the foreleg and uniserial temporal setae ( Murray & Fittkau 1989). According to Andersen (2018), however, Macropelopia (Bethbilbeckia) chilensis possesses bi- to multiserial temporal setae. Therefore, the foretibial comb may be the only remaining discriminator to separate the male of Macropelopia s. str. from that of Bethbilbeckia . The males collected from the Patagonian Andes will not key past couplet 13 in Murray & Fittkau (1989), because the foretibia is armed with an apical row of long bristles instead of small spines ( Fittkau 1962: 108, Roback 1971: 89). However, the hypopygial gonostylus resembles those of the many species of Macropelopia s. str. rather than Bethbilbeckia in the broad base and the constricted apical one third (Fittkau & Murray 1989). In the key to Afrotropical chironomid genera by Ekrem et al. (2017), M. (Macropelopia) patagonica sp. n. keys to Macropelopia (couplet 23) if tibial comb is present on fore leg. Therefore, it is considered that the species belongs to Macropelopia s. str. and the apical row of long bristles on the foretibia may be homologous with the foretibial comb consisting of small spines.