Comprehensive Description

provided by Smithsonian Contributions to Zoology
Cyamops halteratus Sabrosky

Cyamops halteratus Sabrosky, 1958:170; 1965:820 [Nearctic catalog].

DESCRIPTION.—Length of 1.65–1.95 mm; wing length 1.70–2.0 mm; wing width 0.60–0.80 mm. Length of 2.30–2.55 mm; wing length 2.30–2.50 mm; wing width 0.80–0.90 mm.

Head: Ocellar tubercle sparsely microtomentose; frons subshiny, moderately microtomentose, with polished area immediately laterad of lateral ocellus; mesofrons deeply concave, velvety black; antenna mostly yellow, with dorsal half and sometimes apex of 1st flagellomere brown; facial region mostly yellow; posterior of gena mostly brown; labellum and palpus mostly white to pale yellow; face in profile shallowly and vertically arched, not angulate; facial carina shallow and narrow; eye sparsely microsetulose. Chaetotaxy: Inner fronto-orbital setae nearly parallel; fronto-orbits very sparsely setulose; arista with 9 or 10 dorsal/3 ventral rays; peristomal setae 7–9.

Thorax: Anepimeron sometimes polished anteriorly; halter mostly white to gray, mostly black at base; mesonotum slightly longer than wide; scutellum conical, disc shallowly convex. Chaetotaxy: Dorsocentral setae 0+1, subequal in length to basal scutellar seta; mesonotal setulae small; scutellar setae 2, the basal pair about length of apical; anepisternum bare. Legs: Mostly yellow; fore coxa pale yellow, with mostly white microtomentum; mid coxa brown on dorsal , whitish microtomentose; mid and hind femora brown on apical –; apical and sometimes subapical tarsomere of each leg brown; spine-like setulae 6–9, black, easy to discern. Wing (Figure 22): Completely hyaline; costal vein ratio I: 2.9 (slide-mounted wing); costal vein ratio II: 2.28–3.33 (slide-mounted wing 3.23); wing ratio: 2.55–3.03 (slide-mounted wing 2.56).

Abdomen (Figures 2, 3, 5): Epandrium polished centrally; 7th tergite a narrow band; 6th–7th sternites as in Figure 3. Terrninalia of (Figure 3): Left surstylus elongate, angulate medially; right surstylus shorter and broader than left; hypandrial process small, width less than base of left surstylus; ejaculatory apodeme (Figure 5) very large, hatchet-like; aedeagal apodeme free from hypandrium.

Female: Head: Antenna sometimes entirely brown; mesofacialia brown to dark brown, shiny on lower of median carina; palpus mostly yellow to mostly brown; median plate of clypeus sometimes polished anteriorly. Abdomen and terminalia (Figure 4, 6, 7): Boundary between 6th and 7th segments weak dorsally; 7th segment completely separate from 8th sternite; 9th tergite (= “epiproct” in J.F. McAlpine, 1981) weakly sclerotized medially; 3 spherical spermathecae.

TYPE MATERIAL.—The holotype male is labeled “Washburn Co Wis T39N R12W B32 25 VIII 1951 Coll R H Jones/HOLOTYPE Cyamops halteratas C.W. Sabrosky [pale pink]/TypeNo 64220 [red]/Cyamops halteratus SABR. det Sabrosky [black submargin].” The holotype is double mounted (glued to celluloid point), is in fair condition (left antenna missing, a hole in scutum), and is deposited in the USNM (64220).

OTHER SPECIMENS EXAMINED.—CANADA. New Brunswick. Glebe Road, Chamcook, 14 Jul 1965, G.E. Shewell (1; CNC). Newfoundland. Portugal Cove (sedge fen), 27 Jun 1987, T.A. Wheeler (1UGE). Nova Scotia. Halifax Co., Lawrencetown, 19–20 Jul 1967, D.M. Wood (1; CNC). Ontario. Ottawa, 4–12 Jul 1956, J.R. Vockeroth (1, 2 CNC); Ottawa, Mer Bleue, 23 Jun–31 Jul 1952, 1958, 1964, 1966, A.L. Melander, D.D. Munroe, G.E. Shewell, J.R. Vockeroth (3, 3; CNC, USNM); Point Pelee National Park, Leamington, 8 Jul 1980, K.N. Barber (3; UGE). Quebec. Old Chelsea, 18 Jun 1963, J.R. Vockeroth (1; CNC).

UNITED STATES. Massachusetts. Barnstable Co., Woods Hole, 28 Jun–29 Aug 1950, 1954, A.H. Sturtevant (4, 7; USNM); Mashpee, 28 Jul 1950, A.H. Sturtevant (1; USNM). Middlesex Co., Concord (marshy pond), 27 Jul 1961, W.W. Wirth (5; USNM). Plymouth Co., Rochester, 21 Jul 1950, A.H. Sturtevant (2 USNM). New Hampshire. Cheshire Co., Mt. Monadnock, 26 Jul 1926, A.L. Melander (1; USNM). Ohio. Portage Co., Kent (marsh, swept from Carex stricta Lam.), Horning Road, 2 Jul 1989, B.A. Foote (1; USNM). Utah. Rich Co., Laketown, 12 Jul 1938, G.W. Knowlton, F.C. Harmston (1; USNM). Wisconsin. Washburn Co., 6 Jul 1951, R.H. Jones (1 USNM).

DISTRIBUTION (Figure 8).—Nearctic. Canada (NB, NF, NS, ON, QB). United States (MA, NH, OH, UT, WI).
bibliographic citation
Baptista, A. and Mathis, Wayne Neilsen. 1994. "A Revision of the New World Cyamops Melander (Diptera: Periscelididae)." Smithsonian Contributions to Zoology. 1-24.