Peltopsilopa schwarzi Cresson, 1922

Savaris, Marcoandre, Marinoni, Luciane & Mathis, Wayne N., 2016, Revision of the shore-fly genus Peltopsilopa Hendel (Diptera: Ephydridae), Zootaxa 4083 (1), pp. 83-98 : 96-98

Peltopsilopa schwarzi Cresson

(Figs. 7‒9, 12, 49, 52)

Peltopsilopa schwarzi Cresson 1922: 135 [West Indies. Cuba. Cienfuegos: Cayamas (22°14'N, 80°48'W); HT ♀, USNM (25309)]; 1946: 158 [review].─ Malloch 1941: 126 [review].─ Wirth 1968: 12 [Neotropical catalog].─ Mathis & Zatwarnicki 1995: 37 [world catalog].

Diagnosis. This species is distinguished from congeners by the following combination of characters: Body generally shiny, polished, navy blue to dark brown; small to moderately small shore flies, body length 1.77 mm (Figs. 8‒9). Head: Frons shiny, polished with metallic luster; ocelli arranged in isosceles triangle, distance between posterior ocelli greater than between either posterior ocellus and anteromedial ocellus; vertex acutely angled, creased. Antenna yellow to brownish yellow; arista with 7‒11 dorsal rays. Face shallowly arched, shiny, polished, similar to frons, bearing an inclinate seta at lateral margin at midheight; facial ratio 0.50; ventral facial emargination very shallow, almost flat (Fig. 7); dorsal facial seta well developed. Gena-to-eye ratio 0.16. Maxillary irregularly spatulate, blackish brown. Thorax: Almost entirely blackish blue, shiny, microsculptured. Mesonotal length 1.55 mm; acrostichal setae in 2 regular rows on each side, presutural pair slightly enlarged, displaced laterally; scutellum greatly enlarged, longer than scutum, shiny, microsculptured, appearing wrinkled, scutellar length 1.20 mm, almost as wide as long, scutellar length-to-width ratio 0.87, shape in lateral view shallowly domelike, posterior margin bluntly rounded with corners broadly rounded, with basal and apical setae, these setae small, with a few addition setulae laterally and on dorsal surface, but these not conspicuous, ventral scutellar surface shallowly concave; anepisternum with few small light setulae, except for 2 thicker black setae on posterior margin; scutellar base with a dentate, sharp, short projection laterally; katepisternum with a strong dorsal seta. Wing mostly hyaline, whitish, basal fourth, including crossvein r-m, darkened; wing length 1.45 mm; costal vein ratio 0.94‒1.00; M vein ratio 0.73‒0.88. Femora blackish brown except for yellowish apices; tibiae yellow; basitarsomere of foreleg brownish medially, apices yellow, tarsi of mid- and hindlegs yellow to whitish yellow. Abdomen: Tergites blackish brown, shiny; tergites much wider than long; length of tergites 3 and 4 subequal; tergite 5 of male partially telescoped into tergite 4, length slightly more than half of tergite 4.

Type material. The holotype female of Peltopsilopa schwarzi Cresson is labeled “Cayamas 16 5 [16 May; handwritten] Cuba /EASchwarz Collector/ Type No. 25309 U.S. N.M. [red; “25309” handwritten/Holo-TYPE Peltopsilopa SCHARZI E. T. Cresson Jr [maroon; “ Peltopsilopa SCHWARZI ” handwritten]/ Peltopsilopa schwarzi Cress. [handwritten; back submargin].” The holotype is double mounted (glued to a paper triangle), is in excellent condition, and is deposited in the USNM. A female paratype bearing the same locality label as the holotype but with the date of 5 May is deposited in the ANSP. The holotype is a female, not a “ ♂?”, as Cresson noted questionably in the original publication ( Cresson 1922: 135). The paratype is a female, although its wings are folded along the sides of the abdomen, partially blocking any view of its abdomen.

Distribution. Neotropical: Cuba (Cienfuegos) ( Fig. 52 ).

Remarks. Without a male for dissection, our concept of this species is based solely on external characters, but we are confident of these. The photographic plates, especially of the face, will hopefully convey what we have observed and will serve as the primary basis for our conclusions. The ventral facial emargination of this species is very shallow to nearly flat (Fig. 7), while that of the other two species is conspicuously arched. The face is also narrower, with a facial ratio of 0.50 (at least 0.61 in the other species). The scutellum of this species also bears a short, sharp, tooth-like projection anterolaterally (Figs. 8, 12, 49). The other species either lack these projections or they are rudimentary. We also observed that the cuticle of the mesonotum is slightly smoother and that the setular count of the mesonotal rows is less, and there is one less row. We caution readers, however, that this is based on two specimens (holotype and paratype), and that the series is inadequate to access variation adequately. Again, reference to the photographs and illustrations will hopefully convey our observations of these characters better.

Figures

FIGURE 52. Distribution map for Peltopsilopa. Peltopsilopa acuta n. sp. (●); P. anisotomoides (Karsch) (■). P. schwarzi Cresson (▲).