Microcercis trifeminarum, Foster, 2024

Foster, George A., 2024, Revision of Nearctic Microcercis Beschovski (Diptera: Chloropidae), with Synonymy of Incertella Sabrosky, Zootaxa 5481 (4), pp. 401-439 : 423-425

Microcercis trifeminarum new species

http://zoobank.org:act: F8DEFCBC-3CED-4164-9A63-D9A6E33A4379

( Fig. 4, 6 , 24 , 37 )

Diagnosis.—Ocellar triangle mostly gray, occasionally with narrow margins of anterior sides yellow, tomentose; vertex gray; occiput gray dorsally becoming yellow ventrally; postpedicel black dorsally around base of arista or more, remainder yellow; prosternum bright yellow; scutum entirely gray with yellowish tomentum; postpronotal lobe yellow; notopleuron yellow with light grayish center to entirely gray; pleuron mostly tomentose except propleuron and posterior surface of katepisternum polished, with propleuron, anterior portion of anepisternum just behind the anterior spiracle yellow; most of anepisternum light grey except dorsal margin yellow; katepisternum darker gray ventrally, dorsal edge yellow; anepimeron mostly light gray except dorsal edge yellow; legs entirely yellow except hind femur and tibia slightly gray; tibial organ yellow; syntergite 1+2 yellow, remaining tergites brown with narrow yellow posterior margins; male cerci barely discernable; surstylus short, triangulate distally with pointed dorsal tip.

Description.—Body length; female: 1.20–1.73 mm; male: 1.06–1.39 mm.

Head: Ocellar triangle evenly grey tomentose, often with a narrow margin of yellow along both anterior sides; vertex and occiput gray tomentose becoming yellow halfway down behind the eye; frons yellow; scape and pedicel yellow, postpedicel black around base of arista or more, remainder yellow; arista black, pubescent; face, palps, gena and clypeus bright yellow tomentose; prementum polished light yellow/brown, labellum yellow; gena to eye ratio 0.22.

Cephalic chaetotaxy: Fronto-orbital setae light brown to black; interfrontal setae yellowish; ocellar setae gray to black; postocellar setae gray to black; outer vertical setae black; inner vertical setae gray; postocular setae black; vibrissae yellow; subgenal setae yellow.

Thorax: Prosternum bright yellow; prescutum polished black; scutum gray with yellowish tomentum; postpronotal lobe yellow; notopleuron varies from yellow with light grayish center to entirely gray; pleuron mostly tomentose except propleuron and posterior surface of katepisternum polished, with propleuron, anterior portion of anepisternum just behind the anterior spiracle yellow; most of anepisternum light grey except dorsal margin yellow; katepisternum darker gray ventrally, dorsal edge yellow; anepimeron mostly light gray except dorsal edge yellow; metakatepisternum gray; meron mostly yellow; katatergite yellow; anatergite gray; mediotergite polished black below scutellum, lightly tomentose laterally; scutellum gray tomentose except narrowly yellow along posterior margin; wing length 0.94–1.39 mm, hyaline, costal ratios 0.36:0.33:0.12; all legs entirely yellow except hind femur and tibia with slight grayish tint; apical tarsomeres darker than rest of leg, femoral organ two rows of short warts with flattened setae (as in fig. 9); tibial organ narrow, yellow.

Thoracic chaetotaxy: Scapular setae absent; scutum and scutellum with yellow setae and setulae.

Abdomen: Syntergite 1+2 slightly yellowish, remaining tergites mostly brown with posterior margins narrowly yellow, sternites mostly brown with yellow edges. Male terminalia (fig. 37): epandrium grey tomentose; male cerci barely discernable; surstylus short, triangulate distally with pointed dorsal tip. Female cerci black on distal half, basal half yellow.

Distribution.—Nearctic: Canada (Prince Edward Island). United States (Connecticut, Delaware, Florida, Maryland, Massachusetts, New Jersey, South Carolina, Texas, Virginia).

Type material.— The HOLOTYPE male is labeled [white label] DE: Sussex Co.: Angola / Sally Cove: salt marsh/dry sand zone Spartina / 38°38′54.70″N 75°07′45.64″W / 15–16 June 2021 / GA and AM Foster coll.// [white label] ♂ // [red highlighted] HOLOTYPE/ Microcercis trifeminarum Foster ♂ / G. A. Foster 2023 // [inverted white label] USNMENT 01519367 .

The holotype is double mounted (0.15mm minuten inserted in a white cube of silicone rubber on a #2 insect pin), is in excellent condition, and is deposited in the USNM.

PARATYPES (90♂, 73♀):

CANADA.

PRINCE EDWARD ISLAND. Charlottetown , July 1967, N. L. H. Krauss (1♀; NMNH) .

USA.

CONNECTICUT. New Haven Co.: Milford—West Haven , 16 Aug 1978, B. A. Steinly (3♂, 4♀; NMNH) .

DELAWARE. Kent Co.: Bombay Hook , 10 June 1979, A. Friedberg (1♂, 7♀; NMNH) ; Sussex Co.: Angola, Sally Cove , salt marsh grasses, (38°38′54.70″N 75°07’45.64″W), 07 July 2014, G. A. and A. M. Foster (4♂; GAF) ; same data, 03 July 2015, (1♂; GAF) ; same data, salt marsh/wet and dry sand zones, 17–25 July 2021, G. A. and A. M. Foster (21♂, 7♀; GAF) ; same data, dry sand zone grass, (4♂, 5♀; GAF) ; salt marsh, dry sand zone Spartina , 15–16 June 2021, (2♂, 3♀; GAF) ; same data, wet sand zone Spartina , 15–16 June 2021, (6♂, 3♀; GAF) ; same data, salt marsh/wet and dry sand zones, 17–25 July 2021, (1♂, 2♀; GAF) ; same data, salt marsh/dry sand zone grass, 17–25 July 2021, (1♂; GAF) ; same data, sweeping beach grasses, 24–27 Aug 2021, (2♂, 3♀; NMNH) ; same data, salt marsh and dry sand Spartina , 16–17 Sept 2020, (1♂; GAF) ; same data, sweeping salt marsh grasses, 24–27 Aug , 27 Sep–02 Oct 2021, (4♂, 5♀; GAF) ; same data, sweeping beach grasses, 24–27 Aug , 27 Sep–02 Oct 2021, (11♂, 7♀; GAF) .

FLORIDA. Alachua Co.: High Springs , 14 Aug 1968, G. F. Hevel (1♂; NMNH) ; Brunswick Co.: Brunswick , 26 June 1931, no collector (1♀; NMNH) ; Gulf Co.: St. Joseph State Park , 1–3 May 1970, W. W. Wirth (7♂, 2♀; NMNH) ; Levy Co.: Cedar Key , salt marsh, 25 Apr 1970, W. W. Wirth (2♀; NMNH) ; Monroe Co.: Bahia Honda Key , seashore, 11 Apr 1970, W. W. Wirth (1♂; NMNH) ; Big Pine Key , 10 Apr 1970, W. W. Wirth (1♂, 2♀; NMNH) ; same data, malaise trap, 13 Apr 1978, (1♀; NMNH) ; Key West , 23 June 1953, M. R. Wheeler (1♂; NMNH) ; Pinellas Co.: Clearwater , 15 Sept 1976, G. C. Steyskal (2♂; NMNH) ; Taylor Co.: Adams Beach , 24 May 1983, D. S. Chandler (1♂; NMNH) .

MARYLAND. Anne Arundel Co.: Franklin Point State Park , sweeping tall grasses along stream edge, (38°48′47.31″N 76°30′41.49″W), 12 Sep 2022, G. A. and A. M. Foster (1♀; GAF) ; Calvert Co.: North Beach, Walton Beach Nature Preserve , (38°42′44.43″N 76°31′48.43″W), sweeping Spartina on salt marsh, 9 July 2023, G. A. Foster (2♂, 1♀; GAF) ; Queen Anne’s Co .: Kent Narrows , salt marsh, on Spartina patens , (38°57′56.70″N 76°14′02.28″W), 28 Aug 2022, G. A. and A. M. Foster (6♂, 1♀; GAF) ; Worcester Co.: Ocean City , 1, 10 Oct 1949, R. T. Mitchell (3♀; NMNH) .

MASSACHUSETTS. Barnstable Co.: S. Yarmouth, 1 Aug 1939, A. L. Melander (1♀; NMNH) ; Wellfleet , 29 June 1930, A. L. Melander (1♀; NMNH) ; Essex Co.: Salisbury Beach , on beach, 15 Aug 1982, N. E. Woodley (1♂; NMNH) .

NEW JERSEY. Ocean Co.: Barnegat , salt marsh Spartina , (39°51′21″N 76°05′19″W), 15 June 2022, William L. Murphy (1♂; NMNH) ; Tuckerton , 28 Aug 1985, M. J. Raupp (1♀; NMNH) ; Tuckerton, 3 mi. S on Great Bay Blvd. Spartina alterniflora , 20 Aug 1973, R. F. Denno (1♂; NMNH) .

SOUTH CAROLINA. Charleston Co.: 6mi. S. of Adams Run , swept from salt marsh, (32°38′31.16″N 80°20′27.94″W), 12 Apr 1984, B. A. Foote (1♂, 8♀; PADA) .

TEXAS. Galveston Co.: Galveston , 10 June 1917, J. M. Aldrich (2♂; NMNH) .

VIRGINIA. Norfolk Co.: Ocean View , 14 Aug 1969, G. C. Steyskal (1♀; NMNH) .

Distribution.—Nearctic: Canada (P. E. Island). United States (Connecticut, Delaware, Florida, Maryland, Massachusetts, New Jersey, South Carolina, Texas, Virginia).

Discussion.—This species is distinguished from other Microcercis species by the yellow propleuron, the dorsal third of the katepisternum, and a small portion of the meron. The remainder of the pleuron is mostly grey tomentose with only the propleuron and posterior surface of the katepisternum polished. The legs are usually almost entirely yellow.

Etymology.—The name trifeminarum (Latin tri = three; feminarum = women) is feminine. It refers to the three women who relaxed on the boat, often in very hot weather, while the author collected flies on the beach and salt marsh. They are Annette Foster, Nancy Olsen and Karen Power.

Figures

FIGURES 1–8. Microcercis morphology. 1, M. infesta scutal tomentum and setae, 1500X. 2, M. infesta anterior margin of frons, antennal bases, and dorsal portion of carina, 1500X. 3, M. infesta lower face and frontoclypeal membrane, 800X. 4, M. trifeminarum eye, showing density and length of ommatrichia, 1500X. 5, M. infesta frontal and vertical chaetotaxy, 400X. 6, M. trifeminarum scutellum and subscutellum (arrow), 1000X. 7, M. bispina scapular setae (arrows), 400X. 8, M. species proepimeral seta (arrow), 1000X.

FIGURES 23–30. Microcercis and Conioscinella morphology. 23, M. laytoni habitus, lateral view. 24, M.trifeminarum habitus, lateral view. 25, C. ovalis HOLOTYPE habitus, lateral view. 26, M. albipalpis male genitalia, posterior oblique view. 27, M. albipalpis surstylus. 28 M. bispina male genitalia, posterior oblique view. 29, M. dorsata male genitalia, posterior oblique view. 30, M. infesta male genitalia, posterior oblique view.

FIGURES 31–38. Microcercis and Conioscinella morphology. 31, M. insularis male genitalia, posterior view. 32, M. johanni male genitalia, posterior oblique view. 33, M. minor male genitalia, posterior view. 34, M. minor male genitalia, lateral oblique view. 35, M. murphyi male genitalia, posterior oblique view. 36, M. murphyi male genitalia, lateral oblique view. 37 M. trifeminarum male genitalia, posterior oblique view. 38, C. ovalis male genitalia, posterior oblique view.