Eulonchus sapphirinus Osten Sacken, 1877

Borkent, Christopher J., Gillung, Jessica P. & Winterton, Shaun L., 2016, Jewelled spider flies of North America: a revision and phylogeny of Eulonchus Gerstaecker (Diptera, Acroceridae), ZooKeys 619, pp. 103-146 : 117-118

Taxon classification Animalia Diptera Acroceridae

Eulonchus sapphirinus Osten Sacken, 1877 Figs 8, 9, 16D, 17D, 18D, 19D

Eulonchus sapphirinus Osten Sacken, 1877: 276

References.

Osten Sacken 1878: 99 (catalogue); Melander 1902: 181 (California); Aldrich 1905: 221 (catalogue); Kertész 1909: 12 (catalogue); Woodworth 1913: 152 (California); Cole 1919: 36 (key, notes, figs, California, Utah, Oregon), 1927: 422 (male genitalia); Cole and Lovett 1921: 238 (Oregon); Brunetti 1926: 582 (Washington); Essig 1926: 559 (notes, California and Oregon); Knowlton et al. 1939: 6 (Utah); Sabrosky 1948: 389 (key, notes); Schlinger 1965: 404 (catalogue); Cole 1969: 221 (notes); Poole 1996: 36 (checklist).

Common name.

Northern Sapphire or Emerald.

Diagnosis.

Antennal flagellum relatively short, cylindrical or tapered; proboscis straight, shorter than length of body; ocellar tubercle trifurcate; legs yellow; calypter margin pale; body colour metallic green, blue or purple.

Redescription.

Body length: 8.3-11.9 mm, Wing length: 7.1-12.0 mm. Head. Flagellum red-brown or dark brown, male flagellum cylindrical, shorter than head height; scape and pedicel brown; clypeus elongate, extending beyond oral cavity, rounded with flat area dorsally, surface glossy, glabrous, black-brown; labial palp brown, length extending anteriorly beyond proboscis at point of attachment; margin of oral cavity (parafacial) pilose, proboscis length extending to middle of abdomen or equal to abdomen length; ocellar tubercle trifurcate, processes relatively short, subequal (posteromedial processes rounded), height equal to width; median ocellus present, greatly reduced or absent; occiput metallic green-blue, blue or purple, pile densely white or yellow. Thorax. Metallic green, blue or purple, setal pile white or yellow; coxae brown or black with metallic blue (and purple) sheen; femora yellow; tibiae dark yellow; tarsi dark yellow (distal tarsomeres often darker); calypter margin yellow to light brown, membrane transparent or translucent; haltere entirely light brown to yellow. Abdomen. Colour highly variable, metallic olive green, bright green or blue violet, vestiture white or yellow, dominant setae appressed or erect, pile posteriorly directed, marginal band of dense thicker setae on T3-4, or laterally directed pile on T2-4. Male genitalia (Figs 17D, 18D, 19D). Epandrium ovate, thinned at the apex, with posterior margin slightly concave; gonocoxite taller than wide, with broad fenestrae; aedeagus broad at the apex, bilobate in posterior view, not heavily sclerotized laterally.

Type material examined.

Lectotype male (designated here), MCZ, "Webber Lake, Cal/ July 23. O Sacken" [white]; "West. Dipt./ O. Sacken." [white]; "TYPE/ 4/ 1076" [red and white]; "MC-ENT/ 00303277" [white]; "LECTOTYPE ♂/ Eulonchus sapphirinus / Osten Sacken/ Des. C.J. Borkent 2015" [red]; specimen condition: excellent, no parts missing. Body length: 9.2 mm, wing length: 8.7 mm. Paralectotype female, MCZ, "Webber Lake, Cal./ July 23. O. Sack." [white]; "O. Sacken./ West. Dipt." [white]; "Type/ 5/ 1076" [red and white]; " MCZ-ENT/ 00303278" [white]; "PARALECTOTYPE ♀/ Eulonchus sapphirinus / Osten Sacken/ Det. C.J. Borkent 2015" [yellow]; specimen condition: excellent, no parts missing. Paralectotype male, MCZ, "Webber Lake,/ Cal. July 26./ O. Sacken" [white]; "O. Sacken./ West. Dipt." [white]; "Type/ 3/ 1076" [red and white]; " MCZ-ENT/ 00303276" [white]; "PARALECTOTYPE ♂/ Eulonchus sapphirinus / Osten Sacken/ Det. C.J. Borkent 2015" [yellow]; specimen condition: very good, tarsi of both mid legs missing, genetic anomaly with only one antenna present. Paralectotype male, paralectotype female [mating pair on same pin], MCZ, "Webber Lake, Cal./ July 26 O. Sacken" [white]; "O. Sacken./ West. Dipt." [white]; "Aug-Dec 2006 / MCZ Image/ Database" [white]; " Eulonchus / sapphirinus / O.S." [white]; " MCZ-ENT/ 00001076" [white]; "PARALECTOTYPE ♂/ Eulonchus sapphirinus / Osten Sacken/ Det. C.J. Borkent 2015" [yellow]; specimen condition: male, very good, tarsi of hind legs missing, left flagellum missing; female, excellent, no parts missing.

Other material examined.

Listed in Table 3 (Suppl. material 1).

Distribution

(Fig. 20). Nearctic: California, Idaho, Nevada, Oregon, Utah, Washington (USA); British Columbia (Canada).

Ecology.

Eulonchus sapphirinus has been recorded visiting the flowers of 19 different plant families and 30 different species (Table 2). Eulonchus sapphirinus adults have been observed exhibiting strong fidelity to a single flowering plant species, suggesting their role as important pollinators ( Borkent and Schlinger 2008a).

Biology.

Host unknown.

Comments.

Eulonchus sapphirinus is the sister species to the eastern Eulonchus marialiciae as both have characteristic bright green metallic colouration, short proboscis, yellow legs and similar shaped male genitalia. The shape of the antennal flagellum and colour of calypter separate the two species.