Rhamphomyia ecetra Walker, 1849

Sinclair, Bradley J. & Saigusa, Toyohei, 2018, Revision of Francis Walker’s female types of North American Rhamphomyia Meigen (Diptera: Empididae), Bonn zoological Bulletin 67 (2), pp. 129-143 : 132-134

Rhamphomyia ecetra Walker, 1849

( Figs 6–10 )

Rhamphomyia ecetra Walker, 1849: 500 . Type locality: Georgia, USA.

Type material examined. Rhamphomyia ecetra : HOLOTYPE ♀, labelled ( Fig. 8 ): “Type [green margined circle]”; “One of Walkers/ series so named./ EAW [on reverse side: “ Rhamphomyia / ecetra/ Walk.]”;

“ Ecetra ,”; “ Georgia.”; “ Pararhamphomyia ”; “ Holo- / type [red margined circle]; “ BMNH (E) #/ 246919”; “NHMUK010210624 [data matrix code]” ( BMNH). The holotype is missing both hind tibia and tarsus, right fore tibia and tarsi and left wing is slide mounted (see Smith 1971, pl 3, fig. 1).

Additional material examined. UNITED STATES OF AMERICA. Georgia (3 ♀♀, USNM) . North Carolina: Morrison (3 ♀♀, USNM) ( Figs 7, 9, 10 ) .

Diagnosis. Females of this species are distinguished by the dense presutural supra-alar setae; 3 pairs of scutellar setae; dark legs with dorsal and ventral pennate setae on hind femur and tibia, mid femur and tibia and fore tibia, and dorsally only on fore and mid basitarsus; abdomen shiny with reddish margins; cell dm short, distinctive shape, shorter than cell bm; basal costal seta present.

Redescription. Wing length 4.1–4.6 mm. Female. Head dark in ground-colour, with greyish pruinescence on face, frons, postgena and occiput; oral margin shiny reddish. Dichoptic, ommatidia even-sized throughout. Frons and face broad, subequal in width; frons with row of setulae along eye margin ( Fig. 7 ). Ocellar triangle with pair of long ocellar setae, longer than postocular setae. Upper half of occiput bearing row of stout postocular setae, stouter than ocellar setae; lower postocular setae brown, paler than upper setae, slender and shorter. Occipital setae black and stout; postgenal setae paler than occipital setae, long and slender. Antenna brown; scape longer than pedicel; postpedicel nearly 3× longer than basal width ( Fig. 7 ); stylus length about equal to length of scape. Palpus dark, slender, bearing numerous long, dark setae. Clypeus bare, with greyish pruinescence; labrum dark and glossy, nearly 1.5 times longer than eye height; labellum dark and bearing many pale setae, longer than palpal setae.

Thorax dark with dense grey pruinescence; greyish-white vittae between acrostichal and dorsocentral rows; dark vittae beneath acrostichal and dorsocentral rows extending to prescutellar depression; posterior corner of postpronotal lobe and postalar ridge brownish. Prosternum bare; proepisternum at fusion point with prosternum with several long, slender setae; upper part of proepisternum in front of anterior spiracle bare. Antepronotum with dense row of stout setae. Postpronotal lobe with 1–2 outstanding setae, clothed in numerous long, slender setae; acrostichal setae biserial, subequal in length to dorsocentral setae ( Fig. 10 ); dorsocentral setae multiserial, increasing in length posteriorly, prescutellar seta slightly shorter than lateral scutellar seta; presutural supra-alar clothed with numerous slender setae, similar to dorsocentral setae, occasionally with 1–2 outstanding setae (posthumeral); numerous long, slender anterior notopleural setae, similar to presutural supra-alars; 3–4 stronger posterior notopleural setae; 2–3 prealar setae and 1 postsutural supra-alar seta, with numerous shorter setae; 1 postalar seta; 1 long apical pair and 2 shorter lateral pairs of marginal scutellar setae. Laterotergite with cluster of long, dark setae. Anterior and posterior spiracles brownish.

Legs short, slender, brown with grey pruinescence on coxae. Fore coxa with row of long slender anterolateral setae; lateral regions of mid and hind coxae with similar setae. Fore femur with row of fine anteroventral setae, shorter than width of femur. Fore tibia densely clothed in setae, dorsal setae pennate, subequal in length to width of tibia; ventral setae slightly pennate, shorter than width of tibia; apex with several stout subapical setae. Mid femur with dense white ventral pile; anteroventral row of short, even-length setae; posteroventral row of pennate setae nearly as long as width of femur; dorsal setae slightly pennate. Mid tibia with anterodorsal and posteroventral row of pennate setae; 1 stout anterodorsal seta at mid-length and several subapical setae. Hind femur ( Fig. 9 ) with dense white ventral pile; dorsal margin with pennate setae; posteroventral row of pennate setae longer than dorsal row; anteroventral row of setae short and slender. Hind tibia with dorsal and ventral pennate setae, shorter than width of tibia; 3–4 anterodorsal and posterodorsal setae; 1 long seta in posteroapical comb. Tarsomere 1 of fore and mid legs with short dorsal pennate setae; hind leg with 3–4 stout anterodorsal and posterodorsal setae, longer than tarsomere; 3–4 stout anteroventral and posteroventral setae, subequal to width of tarsomere.

Wing infuscate; pterostigma elongate, distinct; long basal costal seta present. Cell dm shorter than length of cell bm ( Fig. 9 ); CuA+CuP reaching wing margin with weakening at mid-length; alular incision acute; margin of calypter with long brown setae. Halter brown.

Abdomen shiny with reddish lateral margins and dark posterior margins; setae dark and numerous. Cercus long and slender, with fine setae.

Male. Unknown.

Geographic distribution. This species is possibly restricted to the southern Appalachian Mountains of Georgia and North Carolina ( USA).

Remarks. Rhamphomyia ecetra is assigned to the R. (Pararhamphomyia) plumifera group sensu Saigusa (unpubl. data) (or perhaps R. obscura group sensu Barták & Kubík 2009) and appears very similar to the species complex of R. brevis Loew, 1861 / R. corvina Loew, 1861 . Rhamphomyia ecetra is characterized by three pairs of scutellar setae and most specimens of the brevis / corvina complex have two pairs of scutellar setae. Males from Georgia are required to make further conclu- sions concerning the identification of this species.

Figures

Figs 6–10. Rhamphomyia ecetra Walker.6. Holotype, female, dorsolateral view; 7. Recent specimen, female antenna, lateral view; 8. Holotype labels, left label underside of corresponding label in centre row; 9. Recent specimen, female, lateral view; 10. Recent specimen, female, anterior view. See Additional material examined section for locality details of recent specimens.