Platyopsis Parent

SCOTT E. BROOKS, 2005, Systematics and phylogeny of Dolichopodinae (Diptera: Dolichopodidae), Zootaxa 857, pp. 1-158 : 100-102

Genus Platyopsis Parent

( Fig. 25 A–E)

Platyopsis Parent, 1929b: 12 . Type species: Hercostomus (Platyopsis) maroccanus Parent [Palaearctic], by monotypy.

Recognition. Platyopsis is distinguished by the following combination of characters: face broad, clypeus strongly bulging and subequal in height to face, mid femur with 2–4 anterior and 2 posteroventral preapical setae, hind femur with 2 anterodorsal preapical setae, hind basitarsus with 1 strong basiventral seta, distal section of M beyond crossvein dm­cu with weak anterior bend before middle.

Description. Head: Vertex not excavated, 1 pair of strong vertical setae, stronger than postverticals. Frons about 2.5–3.0 x wider than high, raised medially, sides weakly converging anteriorly, with violet metallic reflections. Face broad, concave, sides slightly convergent below; clypeus strongly bulging and subequal in height to face, not reaching lower eye margin. Palp large, subtriangular, with weak hairs on outer surface and a distinct apical seta. Proboscis large and thick. Antenna: Scape short, subconical, with well­developed acute medioventral process; pedicel short; first flagellomere triangular; arista dorsal, 2­ segmented, second segment pubescent. Lowermost postocular seta stronger. Postvertical setae stronger than uppermost pair of postoculars.

Thorax: Scutum dull green medially with shining violet longitudinal lateral stripe along each row of dorsocentrals. Acrostichals biserial; 6 dorsocentrals, aligned; 1 strong outer posthumeral, 1 weak inner posthumeral, sometimes indistinct; 2 notopleurals; 1 presutural; 1 sutural; 2 supraalars; 1 postalar. Upper and lower part of propleuron with cluster of fine hairs; lower part of propleuron with 1 strong prothoracic seta; pleural surface in front of posterior spiracle bare; metepisternum bare or with a few fine hairs. Scutellum with 1 strong inner seta and 1 weaker outer seta on lateral margin.

Legs: Pulvilli developed normally on all legs. Foreleg: Femur with 2–3 weak posteroventral preapical setae; apex of basitarsus and tarsomeres 2–5 piliferous ventrally in male. Midleg: Femur with 2–4 anterior preapical setae, 2 strong posteroventral preapical setae in addition to terminal posteroventral preapical seta that is weakly developed. Hindleg: Coxa with strong lateral seta near middle; femur with 2 anterodorsal preapical setae; basitarsus shorter than second tarsomere, with a well­differentiated, strong basiventral seta, longer than width of basitarsus, male with darkened ridge and dentiform process posterobasally.

Wing: Hyaline with weak brown infuscation along crossvein dm­cu and at bend in M. R2+3 nearly straight with anterior apical bend; R4+5 curved posteriorly in distal portion; distal section of M beyond crossvein dm­cu with weak anterior bend before middle, ending before wing apex, convergent with R4+5; crossvein dm­cu equal to or slightly longer than distal section of CuA1.

Abdomen: Subconical. Male: T6 bare; S2 and S3 unmodified; S4 strongly emarginate posteriorly, nearly divided; S5 entirely membranous; S6 Y­shaped, weakly fused with T6 posterolaterally, with narrow, rod­like base extending anteromedially to middle of S5; segment 7 forming short peduncle; S8 heart­shaped, narrowed proximally, setose. Hypopygium ( Fig. 25 A–C) large. Epandrium longer than high, foramen postioned anterolaterally, well­separated from base of cerci; basiventral epandrial lobe moderately developed, with preapical basiventral epandrial seta; apicoventral epandrial lobe narrow, digitiform with 3 apical setae. Surstylus bilobed. Ventral lobe digitiform with rounded apex, with a weak ventral and medial seta near basal third. Dorsal lobe as long as ventral lobe, apex with curved projection. Postgonite with anteroventral portion weakly sclerotized; posterodorsal portion simple, short, not extending beyond edge of epandrium. Proctiger brushes absent. Cercus broad, ovoid, with long, fine marginal setae. Hypandrium long, serrate laterally, free laterally, membranously connected to epandrium basiventrally, hypandrial arms weakly connected to hypandrium, hypandrial apodeme absent. Sperm pump cylindrical, weakly sclerotized; ejaculatory apodeme weakly sclerotized, rod­like; basal sclerite of sperm pump well­developed, straight in dorsal view, with lateral subtriangular projections. Phallus heavily sclerotized in basal half with fin­like process near middle. Female ( Fig. 25 D,E): T6, S6 and S7 undivided, T7 weakly divided medially; T8 and S8 divided medially, tergite and sternite fused anterolaterally forming a narrow sclerite. T10 divided medially into hemitergites each bearing 6–7 spines and a single inner medial spine ( Fig. 25 D), spines pointed apically. Upper lobe of cercus with minute apical seta.

Geographical Distribution. This monotypic Palaearctic genus is known from North Africa, including Morocco and Algeria.

Phylogenetic Relationships. Based on the cladistic analysis, Platyopsis appears to be closely related to Stenopygium and Pelastoneurus ; however, the male genitalia seem closer to Tachytrechus in overall strucure, but without the distinctive upturned and flared postgonite ( Fig. 33 D,E). Platyopsis maroccanus also possesses a strong basiventral seta on the hind basitarsus like Tachytrechus , but this feature is homoplasious and could not be coded into discrete states due to intermediates among the exemplars examined in this study.

Remarks. Parent (1929b) indicated that the type of P. maroccanus was deposited in the Madrid Museum, but I found the male holotype and a female paratype in the MNHN along with a male and female from Arris, Algeria.

Material Examined. Platyopsis maroccanus (Parent) , [PA]: 1ɗ holotype, 1Ψ paratype, 1ɗ, 1Ψ ( MNHN).

Figures

FIGURE 25. Platyopsis maroccanus: (A) Male genitalia, left lateral view (external); (B) Male genitalia, left lateral view (internal); (C) Male genitalia, ventral view (postgonite, surstylus and cerci not shown); (D) Female genitalia, dorsal view; (E) Female genitalia, left lateral view.

FIGURE 33. Tachytrechus notatus and T. angustipennis: (A) T. notatus, male genitalia, left lateral view (external); (B) T. notatus, male genitalia, left lateral view (internal); (C) T. notatus, male genitalia, ventral view (postgonite, surstylus and cerci not shown); (D) T. angustipennis, male genitalia, postgonite dorsal view; (E) T. angustipennis, male genitalia, postgonite lateral view; (F) T. notatus, female genitalia, dorsal view; (G) T. notatus, female genitalia, left lateral view.