Cardiasilus, Soares & Camargo & Lamas, 2025

Cardiasilus gen. nov.

Figs 2 View Figure 2 , 3 View Figure 3 , 4 View Figure 4 , 5 View Figure 5 , 6 View Figure 6 , 7 View Figure 7 , 8 View Figure 8 , 9 View Figure 9 , 10 View Figure 10 , 11 View Figure 11 , 19 View Figure 19

Type species.

Cardiasilus aysu sp. nov. by present designation.

Etymology.

From the Greek feminine word kardia = heart + asilus = common epithet of robber flies. The name refers to the distinct inflated epandria, somewhat heart ideogram-shaped in dorsal view. The gender is masculine.

Diagnosis.

Head. Antenna ~ 3 / 4 as long as eye height (Fig. 2 A View Figure 2 ). Scape and pedicel subequally long (Fig. 2 E View Figure 2 ). Postpedicel lanceolate, laterally compressed and slightly tapering towards apex, about as long as scape and pedicel combined (Fig. 2 E View Figure 2 ). Stylus slightly longer than postpedicel, composed of two elements (Fig. 2 E View Figure 2 ). Face wide, slightly narrowing at antennal level and slightly gibbous at lower 1 / 3, mystax restricted to gibbosity (Fig. 2 D View Figure 2 ). Frons with parallel slopes, slightly concave at antennal level, twice wider than higher (Fig. 2 D View Figure 2 ). Palpus one-segmented, short, ~ 1 / 5 length of proboscis. Proboscis ~ 3.5 / 5 as long as eye height (Fig. 2 C View Figure 2 ). Thorax. Acrostichal setae indistinct (Fig. 2 C View Figure 2 ). Anterior dorsocentral macrosetae absent, scutum with three to four pairs of posterior dorsocentral macrosetae (Fig. 2 C View Figure 2 ). Scutellum tumid with pair of marginal macrosetae (Fig. 2 B View Figure 2 ). Anatergite bare. Postmetacoxal area membranous. Legs. Femora swollen. Wing. Distinctly shorter than abdomen, with bifurcation of veins R 4 and R 5 placed before apex of discal cell by approx. length of r-m cross vein (Fig. 2 G View Figure 2 ). Distance between apex of veins R 4 and R 5 ~ 1.5–2 × longer than distance between apex of veins R 5 and M 1 (Fig. 2 G View Figure 2 ). Cells m 3 and cua closed and petiolate before wing margin (Fig. 2 G View Figure 2 ). Abdomen. Abdominal sternites 2–6 with two to three pairs of pale yellow macrosetae mid-laterally (Figs 2 H View Figure 2 , 6 E View Figure 6 , 9 E View Figure 9 ). Sternite 8 with mid-posterior digitiform projection almost as long as sternite 8 length (Figs 3 E View Figure 3 , 7 E View Figure 7 , 10 E View Figure 10 ). Terminalia. Epandria inflated laterally and posteriorly, resembling the ideogram of heart in dorsal view. Phallus long and thin, longer than length of hypandrium plus gonocoxite, divided into two prongs along its entire length (i. e., Fig. 3 A – C, F – I View Figure 3 ).

Remarks.

Cardiasilus gen. nov. is similar to Myaptex Hull by the inflated male epandria (Fig. 14 A – D View Figure 14 ), but can be easily distinguished by the following set of characters: postpedicel lanceolate, approx. as long as length of scape and pedicel combined (Fig. 2 E, F View Figure 2 ); face slightly gibbous at lower 1 / 3 (Fig. 2 C View Figure 2 ); scutum lacking distinct rows of acrostichal setae; anterior dorsocentral setae absent; femora mostly covered with short black setae (Fig. 2 C View Figure 2 ); male sternite 8 with a long digitiform projection at posterior margin (Figs 2 H View Figure 2 , 3 C, E View Figure 3 ); gonocoxite L-shaped, with rounded apex and covering the gonostylus versus postpedicel oval, shorter than scape and pedicel combined (Fig. 13 C View Figure 13 ); face distinctly gibbous at lower 2 / 3 (Fig. 13 C View Figure 13 ); scutum with two distinct rows of acrostichal setae (Fig. 13 A, C View Figure 13 ); three to four pairs of anterior dorsocentral macrosetae; femora mostly covered with long vestiture of white setae (Fig. 13 A View Figure 13 ); male sternite 8 without projections at posterior margin; gonocoxite squared at base, with a digitiform apicoventral projection acute apically (Fig. 14 F View Figure 14 ) in Myaptex . It is also similar to some undescribed Lecania Macquart species, including Nerax eurylabis (Wiedemann, 1828) a species that belongs in Lecania (unpublished data) with inflated male epandria, but can be easily distinguished by the scutellum with one pair of apical macrosetae and the abdominal sternites with macrosetae (scutellum bare in Lecania or at most bearing tiny, short setulae and sternites only with sparse setae).

Distribution.

The new genus is known to occur only in the state of Mato Grosso do Sul (Central-West Brazil) and department of Cordillera (Central-West of the Oriental Region of Paraguay), in biomes of Pantanal and Chaco, respectively (Fig. 19 View Figure 19 ).