Setacera durani Cresson,

Mathis, Wayne N. & Marinoni, Luciane, 2016, Revision of Ephydrini Zetterstedt (Diptera: Ephydridae) from the Americas south of the United States, Zootaxa 4116 (1), pp. 1-110: 100-102

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Setacera durani Cresson


31. Setacera durani Cresson 

Figs. 133–138View FIGURES 133 – 138, Map 31

Setacera durani Cresson 1935: 348  .— Sturtevant and Wheeler 1954: 202 –203 [review].— Wirth 1965: 755 [Nearctic catalog].— Mathis 1982 b: 38 –40 [revision, Figs. of head, thorax, male terminalia].— Mathis and Zatwarnicki 1995: 253 [world catalog].

Diagnosis. Setacera durani  is similar to S. needhami  and S. trichoscelis  but is distinguished by the following characters: interfoveal facial ridge more explanate; setation of male midfemur lacking conspicuous row of 4–7 larger setae along posteroventral surface; apical tufts of longer hairs of mid- and hindtibiae not as long; 3 rd and 4 th sternites of male with clump of stout setae at posteromedial edge; anal plate of female not as prominent, width greater than length; structures of male terminalia distinctive. Medium-sized to moderately large shore flies, body length 3.40 –5.00 mm; coloration mostly gray to bluish green, generally microtomentose except dorsum which is subshiny to shiny with distinct metallic luster.

Head ( Fig. 133View FIGURES 133 – 138): Head ratio 0.61; frontal ratio 0.48; coloration of frons, fronto-orbital plates, and dorsum of interfoveal ridge concolorous, greenish blue with shiny metallic luster; frons gradually becoming narrower anteriorly, sparsely setose, setae small, generally inconspicuous; ocellar triangle microtomentose, brownish, microtomentose; ocelli in equilateral triangle. Antenna mostly unicolorous, brownish black, microtomentose; scape and pedicel with some grayish green coloration ventrally; arista thickened on basal 1 / 3; basal 2 / 3 with dorsal subpectinate branching, length of longer rays about twice greatest width of arista. Face bicolored; dorsum of interfoveal ridge bluish green, mostly shiny, becoming duller and brownish toward edge of facial ridge; lower portion of face silvery white, from some angles with slight brownish to olivaceous coloration; setae along anterior edge of ridge larger, stout, otherwise facial setae relatively small, generally inconspicuous, uniformly scattered; anterior margin of lower portion of face in profile receding slightly to oral margin. Eye ratio 0.80, orientation of eye at oblique angle to plane of epistoma. Gena-to-eye ratio 0.52; gena mostly concolorous with lower portion of face, posterior portion becoming duller, grayer, with some faint olivaceous coloration.

Thorax: Mesonotum dull, microtomentose along anterior margin, becoming progressively shinier posteriorly, posterior portion distinctly shiny with metallic, slightly brownish green luster; scutellum concolorous with posterior portion of mesonotum; setae other than larger setae reduced, generally inconspicuous. Pleural areas mostly dull, microtomentose to microtomentose; notopleuron with some subshiny to shiny areas like mesonotum above; coloration generally olivaceous to gray, becoming grayer ventrally and anteriorly. Femora mostly gray with some greenish or bluish coloration; tibiae mostly black; hindtarsi mostly concolorous with hindtibia; mid- and foretarsi more yellowish orange. Costal vein ratio of averaging 0.27; M vein ratio 0.79.

Abdomen: Dorsum generally subshiny, extreme anterior margin mostly dull gray, becoming subshiny posteriorly with metallic greenish luster; venter entirely dull, gray to olivaceous green. Tergite 5 of males almost as long as combined length of tergites 3 and 4, becoming narrower to subtruncate posterior edge. Epandrium of male terminalia ( Figs. 135–136View FIGURES 133 – 138) rounded dorsally, lateral margins expanding laterally, broadly truncate ventrally where surstyli attach; surstyli in posterior view ( Fig. 135View FIGURES 133 – 138) fused medially forming broadly U-shaped process with median, pointed process as long as either surstylar arm, each arm broadly rounded and densely setose; aedeagus ( Fig. 136View FIGURES 133 – 138) rather bulbous, broadly produced, rounded apically. Sternites 3 and 4 of males ( Fig. 134View FIGURES 133 – 138) with dense clusters of stout setae at posteromedial edge. Female terminalia, including female ventral receptacle, as in Figs. 137–138View FIGURES 133 – 138.

MAP 31. Distribution map for Setacera durani Cresson. 

Type material. The holotype male is labeled “Los Angeles R[iver]. Cal[ifornia]., Aug. 15, 1916, V. Duran, Coll/Ƌ/ TYPE No. 6515 Setacera DURANI  E T Cresson, Jr. [red].” The holotype is in good condition and is deposited in the ANSP (6516). Cresson's original description lists a female paratopotype, also in the Academy.

Type locality. United States. California. Los Angeles: Los Angeles River (33 ° 45 'S, 118 ° 11.3 'W).

Additional specimens examined. MEXICO. Baja California: San Vicente (31 ° 20 'S, 116 ° 15 'W), 20 Sep 1941, E. S. Ross, G. Bohart (1 ♂; CAS); Santo Domingo (5.7 m E; Hamilton Ranch; 30 ° 44 'S, 115 ° 58 'W), 22 Apr 1963, H. B. Leech, P. H. Arnaud, Jr. (4 ♂, 1 ♀; CAS, USNM); Tijuana (60 km S; 32 °02'S, 117 °01'W), 26 Jun 1950, A. L. Melander (1 ♂; USNM).

Distribution ( Fig. 31View FIGURES 30 – 34). This species occurs in the Southwest of the United States (California, Arizona, Oregon, Nevada, Colorado) and extends into northern Mexico. We have examined many specimens from the three sites in Baja California noted previously.

Natural history. Practically nothing is known about the ecology or immatures of this species. Foote (1982) collected adults from an algal mat that had formed in a small, sewage-polluted stream near Patagonia, Arizona.

Remarks. This species and S. pacifica  are sister species, as evidenced by the joint possession of a median, triangular projection between the surstyli. This species is distinguished externally from S. pacifica  by the evenly rounded, supraspiracular convexity and by the distinct tuft of setae at the apex of the midtibia.


Academy of Natural Sciences of Philadelphia


California Academy of Sciences


Smithsonian Institution, National Museum of Natural History














Setacera durani Cresson

Mathis, Wayne N. & Marinoni, Luciane 2016

Setacera durani

Mathis 1995: 253
Mathis 1982: 38
Wirth 1965: 755
Sturtevant 1954: 202
Cresson 1935: 348