Sphyracephala subbifasciata Fitch, 1855

Feijen, Hans R., Feijen, Frida A. A. & Feijen, Cobi, 2025, A revision of the four Afrotropical and Palaearctic Sphyracephala Say (Diptera, Diopsidae) with an illustrated overview of the other five Sphyracephala, ZooKeys 1241, pp. 1-81 : 1-81

Sphyracephala subbifasciata Fitch, 1855

Figs 101 , 105 , 106 , 107 , 108 , 109 , 110 , 112 , 119–120 , 121–124 , Tables 2 , 3 , 4

Sphyracephala subbifasciata Fitch, 1855: 774. Williston 1908: 314 ( S. brevicornis figure is S. subbifasciata); Curran 1934: 358 ( S. brevicornis figure is S. subbifasciata); Lavigne 1962: 5 (Lavigne - pers. comm. - later indicated that all data refer to S. subbifasciata, except for 1958 records); Cole 1969: fig. 10; Barnes 1988: 110; Peterson 1987: 785 (fig. 61.1 represents S. subbifasciata); Feijen 1989: 84, figs 41–68; Delfosse 2006: 32 ( S. brevicornis figure is S. subbifasciata); Stoaks and Shaw 2011: 232; Lonsdale 2013: table 2, figs 90, 91 (phylogenetic analysis), Londsdale 2020: 6, figs 143–147, 160–168, 188–190, 407; Marshall 2017: 419.

Sphyracephala brevicornis (Say) : Loew 1873: 103. Loew was the first author to ascertain S. subbifasciata as junior synonym of S. brevicornis . Feijen (1989) indicated that Loew based his study of S. subbifasciata on a pair of flies received from Osten Sacken as S. subbifasciata . However, this pair represented S. brevicornis . Till Feijen (1989), all authors followed Loew’s view, while often reporting on a mixture of the two species, or one of the two species.

Type series.

USA: lectotype ♀, north of Ottawa , Illinois, 17.x.1854, swept from grass, at base of the bluffs of the Illinois river [~ 41°23'31"N, 88°47'13"W, ~ 150 m] ( USNM, see also Feijen 1989: 84) . Paralectotypes: 2 ♀, same data as lectotype ( USNM) .

Distribution.

Feijen (1989) gave for distribution: South-Eastern Canada and Northern U. S. A. from Northern Colorado to New England. Stoaks and Shaw (2011) extended the known distribution 1200 km westward till Yellowstone National Park, Wyoming.

Illustrations.

Feijen (1989) and Lonsdale (2020) provided drawings of external morphology and genitalia, while Lonsdale also presented some photographs. To this is added photographs (Figs 119 – 124 ) of habitus, head, thorax, wing, fore femur, and abdomen.

Figures

Figure 101. Sphyracephala subbifasciata, eye span plotted against body length.

Figure 105. Eye span plotted against body length for males of eight Sphyracephala species. A single data point for S. nigrimana is also shown.

Figure 106. Eye span plotted against body length for females of eight Sphyracephala species. A single data point for S. nigrimana is also shown.

Figure 107. Geometric morphometric PCA analysis of Sphyracephala wing venation patterns. Grey dots represent landmarks that were placed with the aid of straight (dotted) lines through other landmarks (white dots). Asterisks indicate wings from paratypes of S. europaea (junior synonym of S. babadjanidesi).

Figure 108. Hierarchical clustering analysis of principal component scores from the PCA in Fig. 107, using the average clustering method. Branch labels indicate the Approximately Unbiased p-value (AU) and Bootstrap Probability (BP). Asterisks indicate wings from paratypes of S. europaea (junior synonym of S. babadjanidesi).

Figure 109. Hierarchical clustering analysis of principal component scores from the PCA in Fig. 107, using the complete clustering method. Branch labels indicate the Approximately Unbiased p-value (AU) and Bootstrap Probability (BP). Asterisks indicate wings from paratypes of S. europaea (junior synonym of S. babadjanidesi).

Figures 110–112. 110 Cladogram of Sphyracephala species groups according to Feijen (1989) 111 preferred maximum likelihood phylogeny of the Sphyracephalinae, based on molecular analysis (Jackson 2019, supplemental figure 1, in slightly adapted form). Numbers at nodes represent Ultrafast Bootstrap supports 112 revised cladogram of Sphyracephala species groups.

Figures 119, 120. Sphyracephala subbifasciata, Canada 119 ♀, Hull QC, habitus, lateral view 120 ♂, Hemmingford QC, head, anterior view. Scale bars: 1 mm (119); 0.5 mm (120).

Figures 121–124. Sphyracephala subbifasciata, Canada 121 ♀, Ottawa ON, wing 122 ♂, Hull QC, fore legs 123 ♂, Hull QC, fore femur, inner view 124 ♀, Hemmingford QC, abdomen, dorsal view. Scale bars: 0.5 mm (121, 122); 0.2 mm (123, 124).