Comprehensive DescriptionRead full entry
Male. Body length 6.5–12.0 mm, wing length 6.0–8.5 mm.
Head: Face and frons broadly separated with distinct frontoclypeal suture near mid-face (Fig. 1). Eyes with short hairs between facets. Vertical setae on small elevation; ocellar tubercle prominent with 2 large setae, without hairs; with 2 postocellar setae. Gena absent. Proboscis somewhat sclerotized, slightly enlarged, covered with sparse gray-brown pollen; each labellar lobe with 6 geminately sclerotized pseudotracheae. Antenna of rather uniform shape, size, and color (Figs 1, 8–9); black, scape without dorsal setae; pedicel with apical ring of setae/setulae, longest setae dorsally and ventrally; first flagellomere about as long as wide, broadly pointed apically, arista inserted near midpoint of dorsal edge.
Thorax: Scutum metallic green to green-blue with silver-gray pollen and bronze-red stripes; 0–14 acrostichal setae in a single row; usually 6 dorsocentral setae (6–10 in Liancalus pterodactyl), 2 notopleural setae; 1–3 strong, black postpronotal setae (often with some smaller white hairs), usually 2 presutural intra-alar setae (1 in Liancalus genualis), 1 presutural seta, 2 postsutural supra-alar setae, and 1 postalar seta per side; scutellum usually with 6 large marginal setae (8–9 in Liancalus pterodactyl), no additional hairs; proepisternum with 1 dorsal and 1 ventral tuft of white hairs. Pleura metallic bronze-green, covered with dense silver-gray pollen, without setae or hairs (Fig. 1).
Legs: Legs very long, slender, dark metallic green (Figs 8–9). Coxa I uniformly covered with white hairs on anterior surface; coxa II with white hairs on anterior surface and black ad seta near middle; coxa III with a black dorsal seta near middle (Fig. 1). Femur II and III with a slender preapical ad seta near 3/4. Tarsus I either with tarsomere 1 long and tarsomere 2 short (Figs 3A–E), or with tarsomere 1 short and tarsomere 2 long (Figs 3F–G).
Wing: Modified with dark brown markings and spots, sometimes enclosing a white apical spot and sometimes with lobes and setae (Figs 4–7). Calypter yellow with a fan of long, pale yellow setae. Halter pale yellow.
Abdomen: Cylindrical, elongate, and slightly broadened at apex (Fig. 2). T5 prolonged ventrally into two lateral flap-like projections that form a hood or pocket for the apex of the hypopygium. Hypopygium (Figs 10–12) nearly round, capping apex of abdomen. Phallus arched to rather sharply bent dorsally just before apex, with apical margin minutely serrate. Hypandrium rather broad, thin, arched anteriorly near apex with lateral lobe bearing setulae and a larger seta at or near apex. Epandrium with large, apical, thin, nearly transparent lobe that is hinged and can be raised or lowered dorsoventrally; at rest, this lobe sits against and covers the surstylus and base of cerci. Surstylus somewhat pointed, strongly sclerotized, directed medially, with large spatulate seta near apex. Cerci broad basally, with either very short (Figs 2E–F, 12) or very long filaments that project anteriorly below abdomen (Figs 2A–D, 8).
Female. Body length 5.0–9.0 mm, wing length 5.5–7.5 mm. Lacking typical male secondary sexual characters and similar to male except: face broader, nearly parallel-sided; palpi larger; fore tarsi unmodified; wings unmodified, but with diagnostic dark brown spots in most specimens (Fig. 16); abdomen shorter and somewhat flattened dorsoventrally.
Immatures. Larvae twelve segmented, cylindrical, truncate posteriorly and tapered anteriorly, opalescent with transparent cuticle; antenna with basal ring bearing sensilla; mouthparts dark brown to black, labrum large with pointed tip (sometimes hooked and/or with tooth-like projections), mandibular hook well developed; metacephalic rods enlarged at caudal tips, longer than tentorial arm. Pupa with prothoracic respiratory horns about 2 mm long, sharply pointed at tips; frontofacial sutures distinct, brown; abdominal segments 2–7 with rows of posteriorly-directed spines. Coccon elliptical, externally composed of sand grains and sometimes moss and mud, inner surface smooth; respiratory horn tips exposed. See Vaillant (1948), Corpus (1986) and Masunaga (2001) for illustrations and photographs of immature stages.