Amplisegmentum venezuelensis, Winterton, 2021

Winterton, Shaun L., 2021, A new species of Amplisegmentum Webb (Diptera: Therevidae) from Venezuela, Zootaxa 4927 (4), pp. 576-582 : 578-580

Amplisegmentum venezuelensis sp. n.

( Figs 1–4 )

https://zoobank.org/ urn:lsid:zoobank.org:act:50AB146A-D8E9-4478-A7D5-A6C88D24A973

Diagnosis. Parafacial setae absent; palpus with greatly elongate setal pile; male eye slightly wider than ocellar tubercle; dorsocentral setae absent; single supra-alar macroseta present; mid coxa with posterior surface lacking setae; wing hyaline with dark infuscation at apices of basal-medial, subcostal and discal cells; male phallus with dorsal apodeme tapered anteriorly, distiphallus directed slightly dorsally.

Description. Body length: 7.2 mm (male). Head with greyish-silver pubescence, darker band across frons ( Fig. 2 ) admixed with erect dark filiform setae; frons wider than ocellar tubercle at narrowest point; parafacial without setae; occiput with sparse silver pubescence and elongate, curved, black macrosetae scattered medially and concentrated as a single row along postocular ridge, setae finer and pale laterally to gena; gena with sparse pile of fine white setae and small patch of short dark setae ventrally, adjacent to parafacial; labellum dark; palpus with sparse but greatly elongate, dark, filiform setae; antenna dark, scape with greyish-silver pubescence and with robust, black macrosetae, larger dorsally; pedicel with greyish-silver pubescence and band of small dark setae; flagellum dark brown. Thorax overlain with greyish-silver pubescence, scutum with brown pubescence in broadly tessellate pattern, admixed with elongate, erect, black, filiform setae; scutal macrosetae black; pleuron and scutellum with sparse pile of elongate, white, lanceolate setae; coxae and femora silver pubescent with pale lanceolate and filiform setae, macrosetae black; femora ground colour dark with silver pubescence, short adpressed, lanceolate setae white dorsally, longer and erect lanceolate setae ventrally admixed with black and white filiform setae; legs with all macrosetae black; tibiae dark yellow to brown apically; tarsi brown; haltere brown; wing ( Fig. 1 ) hyaline, venation brown with slight brownish infuscation on membrane along veins, brown infuscate along anterior margin of wing, as well as brown spots distally on basal medial and discal cells. Abdomen with dense grey velutinous pubescence, admixed with white, lanceolate setae on all segments tergites 2–5, more elongate laterally, terminalia dark yellow ( Fig. 3 ). Male genitalia ( Figs 3 , 4 ) with epandrium quadrangular, posterolateral corners with broad flange, elongate pale lanceolate setae longer laterally; cerci rounded with short filiform setae; gonocoxite broadly rounded, quadrangular posteriorly with small outer gonocoxal process with three large, black, posterolaterally directed setae, remaining setae all white lanceolate; gonocoxal apodeme very small; hypandrium absent; ventral lobe elongate, narrowed distally; inner gonocoxal apodeme elongate, truncate apically with elongate setae; gonostylus robust with strong keel and acuminate apex, filiform seta present medially; phallus with dorsal apodeme of parameral sheath large, flattened in profile; ventral apodeme relatively large, narrow, recurved dorsally; distiphallus narrow and slightly curved dorsally; ejaculatory apodeme narrow, relatively small. Female unknown.

Etymology. The species epithet refers to the collecting locality in Venezuela.

Comments. This species is known only from a single male specimen in relatively poor condition. Amplisegmentum venezuelensis sp. n. is easily distinguished externally from A. ecuadorensis by the lack of parafacial setae and dorsocentral macrosetae, the male frons wider than the anterior ocellus and small wing spots at the apices of the basal medial and discal cells.

Type material. Holotype male, VENEZUELA: Mérida: Puente Real [8.4823, -71.3900], 6.i.1982, C. Boudón les. ( California State Collection of Arthropods ).

Figures

FIGURE 1. Amplisegmentum venezuelensis sp. n., male holotype, dorsolateral view. Body length: 7.2 mm.

FIGURE 2. Amplisegmentum venezuelensis sp. n., male holotype head.

FIGURE 3. Amplisegmentum venezuelensis sp. n., male genitalia, ventral view.

FIGURE 4. Amplisegmentum venezuelensis sp. n., male genitalia.A. epandrium; B. gonocoxites, ventral view; C. same, lateral view; D. phallus, lateral view; E. same, dorsal view. Scale line: 0.2 mm. Abbreviations: d, distiphallus; da, dorsal apodeme of parameral sheath; ea, ejaculatory apodeme; gs, gonostylus; igp, inner gonocoxal process; vl, ventral lobe.