Rocetelion, Matile, 1988

Fitzgerald, Scott J., 2019, A Revision of the Holarctic Genus Rocetelion Matile (Diptera: Keroplatidae), Zootaxa 4648 (3), pp. 568-580 : 569

Key to species of Rocetelion

1 Males .............................................................................................. 2

- Females............................................................................................. 4

2 Males with gonostylus apically rounded ( Figs. 5–6 , 15–16 ) and ventromedial membranous area of gonocoxites T-shaped in ventral view ( Figs. 6 & 16 ); abdomen with or without bands ( Figs. 2 , 14 )......................................... 3

- Males with gonostylus acute apically ( Figs. 3–4 ) and ventromedial membranous area of gonocoxites roughly rectangular, not T-shaped in ventral view ( Fig. 4 ); abdomen banded ( Fig. 1 ); Western Nearctic, California to British Columbia ................................................................................................ fasciola (Coquillett) .

3 Male cerci diamond-shaped ( Figs. 5–6 ); epiproct apically broadly rounded ( Fig. 6 ); posterior edge of tergite nine rounded ( Fig. 5 ); abdomen unbanded, though pale lateral areas present at base of tergites four and five ( Fig. 2 ); mesonotum without longitudinal stripes; Nearctic ; northern boreal distribution, known from Alaska, Michigan, & Ontario .......... fenestrale (Fisher) .

- Male cerci less diamond-shaped/angular and more oval ( Fig. 15–17 ), epiproct apically truncate with a small median depression ( Fig. 17 ), posterior edge of tergite nine more truncate ( Fig. 15 ); abdomen banded ( Fig. 14 ); mesonotum with longitudinal stripes; Palearctic.................................................................... humerale (Zetterstedt) .

4 Nearctic............................................................................................. 5

- Palearctic (no female specimens of humerale were studied so it is keyed here based solely on distribution)................................................................................................. humerale (Zetterstedt) .

5 Female tergite10 triangular, broad anteriorly, narrowing to a point posteromedially ( Fig. 9 ), and sternite 10 posteriorly more tapered ( Fig. 10 ) and not as broadly rounded as in R. fasciola ( Fig. 8 ); Northern boreal distribution, known from Alaska, Michigan, & Ontario ......................................................................... fenestrale (Fisher) .

- Female tergite 10 small and with a truncate posterior edge ( Fig. 7 ), and sternite 10 broadly rounded apically ( Fig. 8 ); Western Nearctic, California to British Columbia .................................................... fasciola (Coquillett) .

Figures

FIGURE 1. R. fasciola, male, habitus (British Columbia, Canada). Scale bar = ca. 1.0 mm.

FIGURE 2. R. fenestrale, male, habitus (Alaska, USA). Scale bar = ca. 1.0 mm.

FIGURE 14. R. humerale, male habitus (Slovakia). Photo by Jan Ševčík.

FIGURES 3–6. Male terminalia of R. fasciola (3,4) and R. fenestrale (5,6). 3, 5 – dorsal view, 4, 6 – ventral view. Scale bars = ca. 0.5 mm. Abbreviations: cer, cerci; ep, epiproct; gc, gonocoxite; gs, gonostylus; ma, membranous area; T9, tergite 9.

FIGURES 15–17. Male terminalia of R. humerale. 15. Dorsal. Scale bar = ca. 0.5 mm. 16. Ventral. Scale bar = ca. 0.5 mm. 17. Dorsal; Tergite nine, cerci, and epiproct. Scale bar = ca. 0.25 mm. Abbreviations: cer, cerci; ep, epiproct; gc, gonocoxite; gs, gonostylus; ma, membranous area; T9, tergite 9.

FIGURES 7–10. Female terminalia of R. fasciola (7,8) and R. fenestrale (9,10). 7, 9 – dorsal view, 8, 10 – ventral view. Scale bar = ca. 0.5 mm. Abbreviations: cer, cerci; S7, sternite 7; S8, sternite 8; S10, sternite 10; T7, tergite 7; T10, tergite 10.