Macrostomus melanothorax Rafael & Cumming, 2009

Rafael, José Albertino & Marques, Dayse Willkenia A., 2021, Four new species of Macrostomus Wiedemann and a checklist of Empididae s. str (Diptera) from Peru, Zootaxa 4981 (3), pp. 506-530 : 511

Macrostomus melanothorax Rafael & Cumming

( Figs 4A–L )

Macrostomus melanothorax Rafael & Cumming, 2009: 45 . Type locality: Brazil, Amazonas , Jaú National Park.

Diagnosis. Male. Postcranium black with gray pruinescence; thorax and abdomen shiny black, legs predominantly yellow ( Fig. 4A ); distal section of vein M 4 longer than vein dm-m ( Fig. 4B ); male tergite 8 acute distally ( Fig. 4C ); epandrium with posterodorsal lobe somewhat thin and higher than anterodorsal lobe ( Fig. 4D ); anterior cercus narrow, with distinct falciform mesial process ( Fig. 4F ); cercal bridge small, subtriangular ( Fig. 4F ); median cercus well elevated with distinct setae ( Fig. 4E ); posterior cercus with three branches distally ( Figs 4E, F ); ventral process of cercus inconspicuous; hypandrium ( Fig. 4H ) with few posterior setae at basal half.

Female ( Fig. 4I ). Without pinnate scales on hind tibia; wing approximately as wide as male wing, rather hyaline; tergite 8 elongate, wider at base, with distal sinus ( Fig. 4J ); sternite 8 higher laterally on posterior third and ventrally with two less sclerotized spots at distal one quarter ( Figs 4J, K ); genital fork well sclerotized, slightly Tshaped ( Fig. 4L ), with genital chamber membranous with small sclerotized area ( Fig. 4L ).

Geographical records. Brazil, Peru.

Material examined. According to Rafael & Cumming (2009).

Remarks. This species was described based on both sexes from Brazil (Amazonas: Novo Airão and Manaus municipalities) and one female specimen from Peru (Madre de Dios: Manu Reserve, Pakitza). The latter needs to be associated with a male specimen from the same locality in order to ensure it is conspecific with Brazilian specimens of M. melanothorax . Additionally, this species is externally very similar to M. apicalis in the pattern of the wing and it will be necessary to study the female genitalia of the holotype of M. apicalis (unfortunately not drawn 30 years ago) in order to verify a possible synonymy between M. apicalis and M. melanothorax .

Figures

FIGURE 4. Macrostomus melanothorax Rafael & Cumming, 2009. Holotype ♂ (A–H).A. Habitus, lateral view (apex of abdomen detached); B. Wing; C. Tergite 8, dorsal view; D. Epandrium detached, lateral view; E. Epandrium and cerci lobes, lateral view; F. Cerci lobes, cercal bridge and subepandrial sclerite, anterodorsal view; G. Cerci lobes, dorsal view; H. Hypandrium and phallus, lateral view. Paratype ♀ (I–L) from Brazil. I. Habitus, lateral view; J. Tergite 8 and sternite 8, lateral view; K. Sternite 8, ventral view; L. Genital fork and genital chamber, dorsal view (Figs J–L after Rafael & Cumming (2009)). Scale bars, figures A, I = 1 mm; B = 0.5 mm; C, H, J–K = 0.2 mm; D–G, L = 0.1 mm. Abbreviations: a ce, anterior cercus; c brd, cercal bridge; m ce, median cercus; mpac, mesial process of anterior cercus; p ce, posterior cercus; sbepand scl, subepandrial sclerite.