Homalocnemis praesumpta Collin 1933
Creators: name: Rafael, José A.
name: Marques, Dayse W. A.
name: González, Christian R.
name: Sinclair, Bradley J.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Homalocnemiidae
Homalocnemis
Homalocnemis praesumpta

description: Homalocnemis praesumpta Collin, 1933
(Figs 13–27, 28)
Homalocnemis praesumpta Collin, 1933: 31, figs. 6b, c. Type-locality: Ancud, Chiloé Is., Chile.
Syntypes. Four males, one female (NHMUK); one male (OUMNH). See Pont (1995: 135) for label details.
Distribution. Chile: Región de La Araucanía: Malleco Province (Termas de Tolhuaca, Sierra de Nahuelbuta); Región de Los Lagos: Osorno Province (PN Puyehue, Termas Aguas Calientes), Llanquihue Province (Ensenada, Puerto Varas); Chiloé Province (Ancud, Chiloé I.) (Fig. 28).
References. Stuardo, 1946: 104 (cat.); Smith, 1967: 9 (cat.); Chvála, 1991: 13 (com.); Pont, 1995: 135 (typ.); Yang et al., 2007: 280 (cat.).
Diagnosis. In addition to features in the key, this species is distinguished by the absence of a digitiform epandrial process, male cerci fused to surstylus posterolaterally and female sternite 8 greatly enlarged, and apex deeply bilobed.
Redescription. Wing length: 4.4–6.1 mm. Male (Figs 13–21). Predominantly black with mesopleuron and coxae gray pruinose (Fig. 13). Front of scutum entirely dull black; prescutellar depression with broad, rectangular pruinose patch. Palpus with long blackish setae (Fig. 14). Wing infuscate, anal lobe weakly developed (Fig. 15). Vein R 2+3 gently upcurved distally, ending after level of branching of vein R 4+5. Section between veins R 2+3 and R 4 shorter than section between veins R 4 and R 5 (Fig. 15). Hind tarsomere 1 not swollen. Tergite 8 half-length of respective sternite (Figs 16, 17), narrowed medially; sternite 8 with desclerotized or depigmented medial area (Fig. 17); remaining pregenital sclerites unmodified. Terminalia highly sclerotized. Epandrial lamellae broadly quadrate, somewhat inflated, fused narrowly along dorsal bridge; without subapical process (Fig. 18). Cercus laminar, narrowly tapered anteriorly; broadly fused to surstylus posterolaterally (Fig. 18). Hypoproct membranous, clothed in minute setulae (Fig. 18). Subepandrial sclerite broadly V-shaped, extending as bacilliform sclerites to surstylus; surstylus fused broadly with epandrium (Fig. 18). Hypandrium with gonocoxal apodeme well developed, expanded horizontally; gonocoxal apodemes united dorsally by upright phallic plate (Fig. 19); phallic plate tapered dorsally to base of subepandrial sclerite, opposite dorsal bridge of epandrial lamellae. Postgonites fused dorsally across hypandrium into elongate, upright digitiform process, rod-shaped with rounded apex (Fig. 19). Apex of hypandrium articulated with phallus (Fig. 19). Phallus with paired, short, acute lateral projections and deeply forked apex (Fig. 20). Ejaculatory apodeme slender, elongate, positioned within hypandrium, separated from base of phallus (Figs 19, 21).
Female (Figs 22–27). Same pattern of color as male (Fig. 22). Sternite 8 paired, narrowly connected ventrally (Fig. 24), enlarged basally, elongate, posteroventrally directed into projecting lobes; clothed in distinct apical setae (Fig. 23). Syntergite 9+10 absent. Sternite 10 (Figs 25, 26) triangular in dorsal view, with narrow, darkly pigmented anterior margin; dark band loosely connected or separated from pair of thinly sclerotized medial plates. Genital fork not observed, probably not sclerotized. Cercus ovoid (Figs 24–26). Spermatheca well sclerotized, subspherical (Fig. 27).
Material examined. CHILE. Región de La Araucanía: Province Malleco, Termas de Tolhuaca [38°14′06″S – 71°43′58″W], 1989, L. Peña (1♁, CNC); Región de Los Lagos: Prov. Osorno, Parque Nacional Puyehue, Termas Aguas Calientes, 40°44′S – 72°19′W, 440 m, 14–31.i.2017, sweeping, V.C. Silva & D.S. Amorim (1♁, MZUSP; 1♁, INPA); Prov. Llanquihue, Volcán Osorno, 322 m, 41°10′09″S – 72°30′51″W, 8.ii.2011, sweeping, D.S. Amorim (1♁, 1♀, MNNC; 1♁, 1♀, INPA); [Province Malleco], Sierra de Nahuelbuta, W. of Angol, 1200 m, 3.i.1951, leg. Ross & Michelbacher (1♀, CAS) [37°49′40″S – 72°59′27″W]; [Province Llanquihue], 8 miles W. of Puerto Varas, 16.i.1951, leg. Ross & Michelbacher (1♀, CAS) [41°19′27″S – 73°08′41″W].
description: Published as part of Rafael, José A., Marques, Dayse W. A., González, Christian R. & Sinclair, Bradley J., 2022, Review of Homalocnemidae of Chile with a key to species and descriptions of male and female terminalia (Diptera: Empidoidea), pp. 168-178 in Zootaxa 5222 (2) on pages 172-174, DOI: 10.11646/zootaxa.5222.2.5, http://zenodo.org/record/7469935