Ephydra (Ephydra) millbrae Jones

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 : 90-92

28. Ephydra (Ephydra) millbrae Jones

Figs. 124–126 , Map 28

Ephydra millbrae Jones 1906: 155 [ United States. California. San Mateo: Millbrae ; LT ♂ (designated by Arnaud 1979: 349), CAS (4483)].— Aldrich 1912: 96 –98 [biology].— Wirth 1971: 364 –365 [revision].— Arnaud 1979: 349 [lectotype designation].— Mathis and Zatwarnicki 1995: 243 [world catalog].

Ephydra riparia of authors, not Fallén (misidentification).— Hardy 1952: 467 (list, Hawaii).— Sturtevant and Wheeler 1954: 170 [review].

Diagnosis. This species closely resembles other subcongeners but may be distinguished by the short, fairly blunt scutellum and sparsely setose anepisternum of females and by characters of the male terminalia. Moderately large shore flies, body length 4.25–4.90 mm; generally microtomentose, olivaceous to brownish with coppery and bluish vittae.

Head: Mesofrons shiny with bluish green metallic luster. Facial coloration variable, usually whitish but sometimes golden brown dorsally, paler ventrally. Eye nearly round, eye ratio 1.06; gena-to-eye ratio 0.43–0.49.

Thorax: Scutum microtomentose, subshiny, especially posteriorly, grayish green with some metallic bronzish tinges; scutellum of female moderately long, bluntly rounded. Acrostichal setae generally fine; both males and females with distinct, large pair of prescutellar acrostichal setae, prescutellar area of female shallowly swollen, generally inconspicuous, but with several setae; anepisternum, especially of female, with sparse setae along posterior margin. Pleural region olivaceous to dark brown. Wing length 3.80–4.25 mm; costal vein ratio 0.25–0.31; M vein ratio 0.84–0.86. Legs mostly yellowish to reddish, some specimens with femora slightly microtomentose, grayish green; tarsal claws about equal to length of tarsomere 4.

Abdomen: Tergite 5 of male about 1.5X length of tergite 4. Male terminalia ( Figs. 124–126 ): Surstyli expanded and rounded apically in posterior view, pale colored, usually yellowish, generally setose except at apex and is distal concavity on posterior surface; gonite generally broad, apex with well-developed pointed hook; sternal plate transverse with narrow anterior process forming bifurcate sclerite, transversely ridged midportion not strongly convex ventrally; aedeagus with apex rounded in lateral view, with a sharp medial flange on posterior side distally, membranous anterodistal lobe with very well-developed apical spicules and proximal ridges, recurved basal process short, about 1/3 length of straight portion.

Type material. The lectotype male of Ephydra millbrae Jones , designated by Arnaud (1979: 349), is labeled “♂/ Millbrae , San Mateo Co., Cal./Holo- [scratched off] TYPE Ephydra MILLBRAE Jones /7 Ephydra milbrae n. sp. / LECTOTYPE ♂ Ephydra Millbrae Jones det 1974 PHArnaud & VFLee.” The lectotype is pinned directly mounted, is in good condition and is deposited in the CAS (4483). When Arnaud (1979: 349) designated this lectotype, he commented as follows: “Jones described Ephydra millbrae from an unspecified number of males and females, and the type-locality was given as “very abundant along the southwest shore of San Francisco Bay between the small towns of San Mateo and San Bruno, the center of the colony seeming to be about Millbrae , where the floating puparia and adults often cover the entire surface of the small salt-water ponds.” Three paralectotypes were also designated.

Type locality. United States. California. San Mateo: Millbrae (37°35.9'N, 122°23.6'W).

Additional specimens examined. MEXICO. Baja California: Gulf of California, Bahía de Los Ángeles (Gulf of California; 28°55'N, 113°30'W), M. C. Van Duzee (ex; CAS).

Distribution (Map 28): Australasian/Oceanian: Hawaiian Islands (Maui, Oahu). Nearctic: Canada (British Columbia), United States (California, Oregon, Washington). Neotropical: Mexico (Baja California).

MAP 28. Distribution map for Ephydra millbrae Jones.

Figures

FIGURES 124 – 126. Structures of male terminalia of Ephydra millbrae Jones. (124) tergite 5, epandrium, cercus, surstylus, internal structures of male terminalia, lateral view; (125) surstyli, posterior view; (126) surstyli, posterior view.