Comprehensive Description

provided by Smithsonian Contributions to Zoology
Hecamede (Hecamede) australis

DESCRIPTION.—Small to medium-sized shore flies, length 1.85 to 3.00 mm.

Head: Fronto-orbits and ocellar triangle golden gray to mostly whitish gray, densely microtomentose; proclinate fronto–orbital seta 1, inserted anteriad and laterad of reclinate seta; mesofrons distinctly less densely microtomentose than ocellar triangle or fronto-orbits, posterior angles dark colored, brownish, becoming orangish to yellowish orange anteriorly. Antenna yellowish orange, pedicel with sparse microtomentum, flagellomere 1 with slightly dark coloration dorsobasally, near insertion of arista; arista with 5 dorsal branches. Face mostly whitish gray, densely microtomentose; conical facial prominence with apex large and bare; face 3 large lateral setae and 1 or 2 smaller ones ventrad, larger setae arising from bare, slightly raised tubercles; parafacial a gradual transition color between fronto-orbit and whitish gray gena; gena usually with 1 larger seta and several smaller black setae; eye-to-cheek ratio averaging 0.55. Clypeus black with dense investment of gray microtomentum.

Thorax: Mesonotum tan to gray, usually darker than pleural areas, if tan, lateral margins becoming grayer, especially ventrad through notopleuron and dorsal half of anepisternum; presutural seta and prescutellar acrostichal setae well developed; pleural sclerites mostly gray to whitish gray, dorsal portion of anepisternum sometimes faintly tan to golden gray; anepisternum bearing several setulae on dorsal towards posterodorsal angle. Coxae and trochanters blackish gray to gray; middle and hind femora gray anteriorly, posterior surface blackish; fore femur lacking a distinct row of setae along anteroventral surface, anterior surface mostly blackish, mostly gray posteriorly; tibiae, especially fore tibia, mostly yellow but moderately densely invested with whitish gray microtomentum, appearing white to grayish white, only femoral/tibial articulation mostly yellow; fore basitarsus with 2 or 3 black setae, these inserted toward base of posteroventral surface; apical 2 tarsomeres blackish brown. Wing with costal vein ratio averaging 0.40; M vein ratio averaging 0.66; last section of vein M shallowly arched posteriorly.

Abdomen: Male terminalia (Figures 16, 17) as follows: 5th tergum with anterior to more lightly sclerotized and bearing numerous, evenly scattered spicules, from dorsal view with anterior margin broadly bifid, posterior to a sclerotized band bearing 8 to 11 setae along posterolateral margin, with 2 globular apodemes anterobasally; epandrium (Figure 16) a dorsal band, gradually enlarged posteriorly; surstylus (Figure 16) in lateral view long and relatively broad, slightly narrowed toward middle, ventral margin bluntly rounded and bearing 5 or 6 acutely pointed setae and several setulae; cercus (Figure 16) long and narrow, extended nearly to apex of surstylus, bearing a conspicuously longer seta at posteroventral margin; gonite (Figure 17) roughly triangular in shape, with a narrow connection above aedeagus, ventral angle a narrowed, short, parallel-sided, blunt process; aedeagal apodeme (Figure 17) L-shaped in lateral view, slightly broader toward attachment with hypandrium; aedeagus (Figure 17) long and narrow, tapered gradually to apex, shaped like a pipe, with a right angle curve at basal to ; hypandrium slightly emarginate anteriorly.

TYPE MATERIAL.—The holotype male is labeled “Deewhy, New South Wales[,] 24 Feb. 1957 beachdunes/W.W. Wirth collector/HOLOTYPE Hecamede australis W.N.Mathis [species name and gender symbol handwritten, red].” The holotype is double mounted (minuten in a polyporus block), is in excellent condition, and is deposited in the ANIC. The allotype female and 12 paratypes (8, 4; USNM) bear the same locality label as the holotype (dates vary from 15 Jan to 24 Feb 1957). Other paratypes are as follows: AUSTRALIA. New South Wales: Cape Byron, Jan 1961, K.R. Norris (2; ANIC); Durras, 15 Sep 1955, S.J. Paramonov (4; ANIC, USNM). Queensland: Broadbeach (puparia collected 25 May 1966, adult emerged 11 Jun 1966, Z. Liepa (4, 2, 2 puparia; ANIC). Western Australia: Dunsborough, Eagle Bay, 18 Nov 1959, M.M.H. Wallace (2; ANIC).

DISTRIBUTION (Figure 18).—Australasian/Oceanian: Australia. (NSW, QLD, WA).

ETYMOLOGY.—The species epithet, australis, alludes to the continent where this species was collected.

DIAGNOSIS.—This species is distinguished from similar congeners by the following combination of characters: proclinate fronto-orbital setae 1; gena with several black setae; fore femur lacking a distinct row of setae along anteroventral surface; tibiae, especially the fore tibia, mostly grayish, only apex of fore tibia mostly yellow; fore basitarsus with 2 or 3 black setae inserted toward base of posteroventral surface; and structure of the male terminalia (see description and Figures 16, 17), especially the shape of the surstylus and gonite.
bibliographic citation
Mathis, Wayne Neilsen. 1993. "Studies of Gymnomyzinae (Diptera: Ephydridae), IV: A Revision of the Shore-Fly Genus Hecamede Haliday." Smithsonian Contributions to Zoology. 1-46. https://doi.org/10.5479/si.00810282.541