Pelastoneurus arcuatus, Loew, 1861

Soares, Matheus M. M., Runyon, Justin B., Capellari, Renato S. & Ale-Rocha, Rosaly, 2023, Review of Paraclius arcuatus species-group (Diptera, Dolichopodidae) with description of two new species, Zootaxa 5323 (2), pp. 151-182 : 152-153

publication ID	https://doi.org/ 10.11646/zootaxa.5323.2.1
publication LSID	lsid:zoobank.org:pub:0ABC4CFF-9D2A-449A-B7C2-CFE16DF16004
DOI	https://doi.org/10.5281/zenodo.8212575
persistent identifier	https://treatment.plazi.org/id/03E62055-FF90-0014-FF7B-F968FEF534FA
treatment provided by	Plazi
scientific name	Pelastoneurus arcuatus
status

Treatment

The arcuatus View in CoL -group of Paraclius

Diagnosis (males). Head. Face gradually narrowing below (funnel-shaped), the narrowest point slightly wider than the mid ocellus (e.g. Figs 1D View FIGURE 1 , 2C View FIGURE 2 , 7E View FIGURE 7 ). Clypeus short, about 1/4 as long as face (e.g. Figs 1D View FIGURE 1 , 2C View FIGURE 2 , 8C View FIGURE 8 , 11C View FIGURE 11 ). Palpus oval, short, with 1 strong apical seta, shorter than palpus (absent in P. xibun sp. nov.). Antenna dark brown to black; postpedicel suboval, subtriangular or subrectangular; arista-like stylus two-segmented, shorter than eye height, first segment usually arched, second segment long, about 2–3X longer than first segment and with dense and short microtrichia (e.g. Figs 1E View FIGURE 1 , 2E View FIGURE 2 , 8E View FIGURE 8 ). Thorax. Mesonotum with 5 pairs of strong dorsocentral setae; acrostichals short, biseriate, ending at level of the fourth posterior dorsocentral seta (e.g. Figs 8B View FIGURE 8 , 11B View FIGURE 11 ). Wing. Long and narrow; anal lobe barely developed; vein M 1 strongly bowed towards R 4+5, weakly to strongly concave posteriorly; vein M 1 ending before distal portion of wing apex; vein M 4 longer than dm-m (e.g. Figs 1I View FIGURE 1 , 2F View FIGURE 2 , 8F View FIGURE 8 ). Legs. Legs unmodified, only ventral surface of tarsus I covered with weak whitish pile (e.g., P. arcuatus ). Femur I with anteroventral row of short setae increasing in length at apex; femur II with anteroventral row of setae, ending in 2–3 more conspicuous setae and with 1 strong anterior preapical seta at 5/6; femur III laterally compressed, with anteroventral and dorsal rows of setae, anteroventral row increasing in length towards apex, and 1 strong anterior preapical seta at 5/6.

Abdomen. Tergites 1–5 setose, tergite 6 either with short or long and strong lateral setae (e.g. Figs 1H View FIGURE 1 , 8D View FIGURE 8 , 9F View FIGURE 9 , 11E View FIGURE 11 ) (bare in P. arcuatus ( Fig. 2D View FIGURE 2 )), segment 7 forming a long (usually as long as hypopygium) and well sclerotized peduncle; sternite 6 plate-like, weakly connected posteriorly to tergite 6 (e.g. Figs 3A View FIGURE 3 , 9A View FIGURE 9 , 12A View FIGURE12 ). Hypopygium: Epandrium narrow, about 2.5–3X longer than high, with lateral ridge forming an acute apicoventral projection. Apicoventral epandrial lobe not developed, but recognizable by two apicoventral epandrial setae (e.g. Figs 3G View FIGURE 3 , 9E View FIGURE 9 , 12D View FIGURE12 ); basal apicoventral epandrial seta usually longer than ventral lobe of surstylus. Ventral lobe of surstylus somewhat digitiform or L-shaped, weakly to strongly curved ventrally, with 1 stout modified apical seta (e.g. Figs 9C View FIGURE 9 , 12D View FIGURE12 , 16D View FIGURE 16 ). Dorsal lobe of surstylus shorter than ventral lobe and weakly sclerotized, usually with strong setae at ventral and/or apical edges (e.g. Figs 3F View FIGURE 3 , 9J, K View FIGURE 9 , 12D View FIGURE12 ). Phallus divided into two narrow and strong sclerotized arms, coated with a thin membrane, with small bumps or spinules at base of exposed part, apical part with dentiform or rounded processes (e.g. Figs 3D View FIGURE 3 , 12F View FIGURE12 , 16E View FIGURE 16 , 20E View FIGURE 20 ) (with fringe of spines in P. angustipennis Van Duzee ( Fig. 9C, D View FIGURE 9 )). Hypandrium as long as exposed part of phallus, strongly sclerotized, trough-shaped, with weak connection to epandrium basally, free laterally, apex bifurcate and weakly sclerotized (e.g. Figs 3E View FIGURE 3 , 9I View FIGURE 9 , 16G View FIGURE 16 ) (apex strongly sclerotized in P. xibun sp. nov. ( Fig. 20F View FIGURE 20 )), somewhat arrow-shaped, lateral margin usually with dentiform preapical processes, base of hypandrium projecting up inside epandrial capsule, cradling the phallus. Sperm pump short, well sclerotized, somewhat kidney-shaped, pipe-shaped or C-shaped, about 1/2 to 1/3 as long as ejaculatory apodeme (e.g. Figs 3D View FIGURE 3 , 9C View FIGURE 9 , 12E View FIGURE12 ). Ejaculatory apodeme usually strongly sclerotized (weakly sclerotized in P. brooksi sp. nov. ( Fig. 12E View FIGURE12 )), long and narrow, about 1/2 as long as epandrium and slightly widening apically (e.g. Figs 3D View FIGURE 3 , 9C View FIGURE 9 , 16E View FIGURE 16 ). Proctiger weakly sclerotized, dorsoventrally flattened (e.g. Figs 12E View FIGURE12 , 16E View FIGURE 16 ) (modified in an undivided proctiger brush in P. arcuatus ( Fig. 3D View FIGURE 3 )). Cercus short, suboval or drop-shaped, about 1/3 to 1/2 as long as epandrium, lacking basolateral tail (e.g. Figs 2D View FIGURE 2 , 9G View FIGURE 9 , 12B View FIGURE12 ). Females. Similar to male in habitus and chaetotaxy, differing mainly by the face and clypeus wider (both wider than ocellar tubercle), with eyes almost parallel sided and the short postpedicel, about as long as wide (e.g. Figs 4B, C View FIGURE 4 , 10B, C View FIGURE 10 , 13B, C View FIGURE 13 ).

Included species. P. arcuatus ( Loew, 1861) , P. pumilio Loew, 1872 and the following newly ascribed species: Paraclius angusticauda Van Duzee, 1933 , P. angustipennis Van Duzee, 1929 , P. brooksi sp. nov., P. elongatus Van Duzee, 1930 , and P. xibun sp. nov.

Remarks. Brooks (2005) was the first to mention the Paraclius arcuatus species-group ( Paraclius sensu stricto) composed of the following species: Paraclius arcuatus , P. pumilio and “ Paraclius sp. 1 ”. However, after gathering information from descriptions, photos of types and identified material of nearly all New World Paraclius we found additional species that fit this group. The Paraclius arcuatus species-group is a small lineage whose monophyly is supported by the characters discussed below (see Discussion section), mainly by the male face narrowing below, clypeus short, about 1/4 as long as face, the absence of a developed apicoventral epandrial lobe, the acute apical ridge of epandrium and the trough-shaped hypandrium.

Distribution. The group is mostly restricted to Central and North America, with some species reaching the Caribbean Islands. The distribution range is from Northern USA to Costa Rica in Central America and the Caribbean islands of Cuba, Jamaica, Grenada, and Saint Vincent and the Grenadines, not reaching mainland South America ( Figs 22 View FIGURE 22 , 23 View FIGURE 23 ).