Pteremis wirthi ( Marshall, 1984 )

Roháček, Jindřich, 2024, The genus Pteremis (Diptera: Sphaeroceridae) in the West Palaearctic area, with description of four new species, Acta Entomologica Musei Nationalis Pragae 64 (1), pp. 153-206 : 203

Pteremis wirthi ( Marshall, 1984)

Leptocera (Pteremis) wirthi Marshall, 1984: 397 (both sexes, illustr.). Type locality: Canada, Quebec, Mt. Albert , Gaspé Provincial Park. Holotype: J (CNCI).

Pteremis wirthi : RoHÁĆFK et al. (2001): 212 (world catalog, generic combination).

Material examined. CANADA: ONTARIO: Algonquin Provincial Park, Swan Lake Station, Scott Lake Survey, Sphagnum , 6.v.1995, 3JJ 1♀ (1 J 1 ♀ f. brach), S.A. Marshall leg. et det. ( DEBU, 1 J 1 ♀ genit. prep.). Comments. This Nearctic species was described by MARsHALL (1984) as a very close relative of P. fenestralis differing from the latter species by its longer stpl seta and brown gena and some detail of the structure of gonostylus. However, this wing polymorphic species also differs from P. fenestralis in having wings of a macropterous form shorter than the abdomen. In order to evaluate its relationships to other species of Pteremis I have examined male and female terminalia of P. wirthi in more detail. Its closest affinity to P. fenestralis has been confirmed (see above under P. fenestralis ) and the most distinct differences against the latter species can be summarized as follows: Male S5 is most similar to that of P. fenestralis both as regards the posteromedial comb of spines and the shape of the pale-pigmented area in front of it but setae on the sides of this area are sparse, longer and more robust. Male genitalia with cercus relatively short and hence most similar to that of P. fenestralis including apical tubercle but the latter is more broad. Anterior lobe of gonostylus with ventral process darkened and formed as in P. fenestralis but anterodorsal process of this lobe is distinctly different, markedly prolonged, more resembling that of P. ferreus (cf. Fig. 106 ) although shorter and more slender, and the posterolateral oblique longitudinal ledge finely long-spinulose; posterior lobe of gonostylus, besides the robust terminal spine with also 2 adjacent setae strongly thickened, spine-like (unlike all congeners). Distiphallus in the middle dorsoventrally dilated (as in most species, except for P. fenestralis ); postgonite not knob-like apically, distally most similar to that of P. pulliceps , cf. Fig. 50 ).

Female S8 different from that of P. fenestralis , distinctly more transverse, its pigmented part with 2 pairs of setae (lateral and medial), those medial very close each to other and its membranous posterior part with a transverse row of 6 setae (2 lateral long), on elevated sockets, resembling that of P. pulliceps (see Fig. 59 ). Spermathecae most similar to those of P. fenestralis , including spine-like tubercles on tapered base but of more elongate to pyriform shape and with distal sclerotized parts of ducts fused relatively close to bodies of paired spermatheacae. Female cerci broad and distinctly flattened as are those of P. fenestralis (cf. Figs 34, 35 ).

Pteremis wirthi can also be recognized by means of the sequence of the barcoding region of COI (see BIN BOLD:ACB 9048 in BOLD database), with pairwise distance from P. fenestralis being about 5%, see https:// v4.boldsystems.org/index.php/Public_BarcodeCluster?clusteruri=BOLD:ACB9048.

Distribution. Nearctic: Canada (Alberta, Northwest Territories, Ontario, Quebec, Saskatchewan) (RoHÁĆFK et al. 2011).

Figures

Figs 104–108. Pteremis ferreus sp. nov., male, paratype. 104 – external genitalia, caudally (aedeagal complex and left gonostylus omitted); 105 – ditto, left laterally; 106 – gonostylus, left laterally; 107 – aedeagal complex (with aedeagus separated), laterally; 108 – male S5, ventrally. Scales = 0.1 mm (Figs 104, 105, 107, 108), 0.05 mm (Fig. 106).

Figs 46–51. Pteremis pulliceps sp. nov., male, paratype. 46 – external genitalia, left laterally; 47 – ditto, caudally (aedeagal complex and left gonostylus omitted); 48 – gonostylus, laterally; 49 – apex of cercus, left laterally; 50 – aedeagal complex, laterally; 51 – male S5, ventrally. Scales = 0.05 mm (Figs 46, 47, 50), 0.03 mm (Figs 48, 49), 0.1 mm (Fig. 51).

Figs 55–61. Pteremis pulliceps sp. nov., male, female, paratype. 55 – male left t2 and mt2 dorsally; 56 – ditto, posteriorly; 57 – ditto, anteriorly; 58 – spectacles-shaped sclerite, ventrally; 59 – S8, ventrally; 60 – S10, ventrally; 61 – spermathecae. Scales = 0.2 mm (Figs 55–57), 0.05 mm (others).

Figs 33–39.Pteremis fenestralis (Fallén, 1820), female.33 – spermatheca; 34 – postabdomen,laterally; 35 – ditto, dorsally; 36 – ditto, ventrally; 37 – paired spermathecae; 38 – S8, ventrally; 39 – S10, ventrally. Scales = 0.05 mm (Figs 33, 37–39), 0.1 mm (others). For abbreviations see Material and methods.