Ephydra (Ephydra) packardi Wirth

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 : 92-94

29. Ephydra (Ephydra) packardi Wirth

Figs. 127–129 , Map 29

Ephydra packardi Wirth 1971: 365 [new name for E. halophila Packard ].— Mathis and Zatwarnicki 1995: 243 [world catalog].

Ephydra halophila Packard 1869: 49 [preoccupied by Coenia halophila von

Heyden 1844: 203, a synonym of E. riparia Fallén ].

Ephydra subopaca , in part of authors [misidentification], not Loew 1864: 98.— Aldrich 1912: 93 [review].— Ping 1921: 557 [natural history, description of immature stages].

Ephydra riparia , in part of American authors [misidentification], not Fallén 1813: 246.

Ephydra macellaria , in part of American authors [misidentification], not Egger 1862: 779.

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. Medium-sized to moderately large shore flies, body length 3.30–4.70 mm; generally microtomentose, olivaceous green to gray.

Head: Mesofrons shiny with bluish green metallic luster. Facial coloration variable, usually whitish but sometimes golden brown dorsally, paler ventrally. Eye ratio 1.06; gena-to-eye ratio 0.47.

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. Wing length averaging 3.39–3.80 mm; costal vein ratio 0.27; M vein ratio 0.78. Legs mostly yellowish to reddish, some specimens with femora slightly microtomentose, grayish green; tarsal claws about equal to length of 4th tarsomere.

Abdomen: Tergite 5 of male about 1.5X length of tergite 4. Male terminalia ( Figs. 127–129 ): 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 halophila Packard (designated by Wirth 1971: 365) is labeled “ E. halophila Pack. Equality Salt works [Gallatin Co.,] Ill[inois]. United States. Packard Coll. [species name, author, and specific locality handwritten, folded label]/M. C. Z holoTYPE 28563 [“holo” and type number handwritten, red]/ halophila Pack. [handwritten, black submargin]/ halophila Pack = subopaca Loew (Sturtevant) [handwritten]/ HOLOTYPE Ephydra packardi Wirth. n[ew]. n[ame]. [species name and author handwritten, red submargin].” Packard (1869) did not designate a holotype, hence the holotype labels are incorrect. Wirth's designation of “ type in MCZ,” however, does qualify as a lectotype designation, and the specimen he labeled as “ HOLOTYPE ” is the lectotype male of this species. The lectotype is double mounted (pin in cork block), is in fair condition (several setae are missing or misdirected, the basal flagellomeres are missing), and is in the Museum of Comparative Zoology, Harvard University, MCZ 28543. There is also a male paralectotype and a vial of puparia in the MCZ.

Type locality. United States. Illinois. Gallatin: Salt works (37°43.3'N, 88°17.7'W).

Additional specimens examined. MEXICO. Baja California Sur: Isla Ildefonso (26°38'N, 111°26.5'W), 30 Mar 1953, P. H. Arnaud, Jr. (4♂, 3♀; USNM). Sonora: Alamos (27°01'N, 108°55.9'W), 26 Feb 1963, P. H. Arnaud, Jr. (1♂; USNM).

Distribution (Map 29): Nearctic: Canada (British Columbia), United States (Arizona, California, Colorado, Idaho, Illinois, Indiana, Kansas, Louisiana, Maryland, Massachusetts, Missouri, Nebraska, Nevada, New York, North Dakota, Oklahoma, Oregon, Texas, Utah, Virginia, Washington). Neotropical: Mexico (Baja California Sur, Sonora), between 26°–52°N and 72°–123°W.

Remarks. This is one of the commonest species of the subgenus Ephydra , and aside from E. millbrae Jones , it is the only species of the riparia group known to occur below the Mexican-United States border.

MAP 29. Distribution map for Ephydra packardi Wirth.

Figures

FIGURES 127 – 129. Structures of male terminalia of Ephydra packardi Wirth. (127) surstyli, posterior view; (128) aedeagus, aedeagal apodeme, hypandrium, lateral view; (129) gonite, lateral view.