Allotrichoma (Allotrichoma) lacteum Cresson

Mathis, Wayne N. & Zatwarnicki, Tadeusz, 2012, Revision of New World Species of the Shore-fly Subgenus Allotrichoma Becker of the Genus Allotrichoma with Description of the Subgenus Neotrichoma (Diptera, Ephydridae, Hecamedini), ZooKeys 161, pp. 1-101 : 35-39

Allotrichoma (Allotrichoma) lacteum Cresson Figs 2732

Allotrichoma lacteum Cresson 1926: 252; 1948: 260 [synonymy with Allotrichoma simplex ]. Wirth 1965: 736 [Nearctic catalog]. Cole 1969: 397 [list]. Mathis and Zatwarnicki 1995: 151 [world catalog].

Description.

This species is distinguished from congeners by the following combination of characters: Small to moderately small shore flies, body length 1.50-2.2 5 mm. Head: Medial facial carina above facial prominence shallow; labella broad, fleshy, shorter than mediproboscis; clypeus microtomentose, usually gray.

Thorax: Presutural supra-alar seta present. Wing with costal vein ratio 0.28-0.32; M vein ratio 0.43-0.47.

Abdomen: Male 5th sternal flap in lateral view (Fig. 31) elongate, digitiform, bear several setulae apically and subapically; 5th medial process in lateral view (Fig. 31) elongate, bar-like, bearing 5 apical setulae. Male terminalia (Figs 27-30): Epandrium in posterior view (Fig. 27) like an inverted U with medial flanges, flanges becoming wider ventrally; epandrium in lateral view (Fig. 28) simple, bar-like, height more than twice width; surstylus robust, greatly widened ventrally, posteroventral and anteroventral corners narrowly angulate, ventral margin bearing numerous short setulae; cercus in posterior view (Fig. 27) pointed dorsally, gradually broadened ventrally then abruptly curved laterally and ventrally as a slightly tapered, elongate process that bears numerous, very long setulae apically; cercus in lateral view (Fig. 28) essentially straight, wider dorsally, ventral half slightly tapered, nearly parallel sided, apex abruptly broadened and bearing numerous, very long setulae; aedeagus in ventral view (Fig. 29) elongate, narrowly ovate, slightly tapered apically, in lateral view (Fig. 30) elongate, somewhat lunate; phallapodeme in lateral view (Fig. 30) triangular, keel shorter than length, pointed; gonite in ventral view (Fig. 29) somewhat bar-like, slightly wider basally, apex with short, lateral process, apex of process bearing a setula, with a subapical, distinct, angulate notch and bearing a subapical setula; gonite in lateral view (Fig. 30) wide basally, gently curved apically, tapered to apical point.

Type material.

The holotype male is labeled "Bill W[illia]ms. For[est,] Ariz[ona]. Aug. F. H. Snow/♂/TYPE Allotrichoma LACTEUM E. T. Cresson, Jr. [maroon; species name handwritten]." The holotype is double mounted, is in good condition (abdomen removed and apparently lost; there is an empty attached microvial with glycerin), and is deposited in the Snow Entomological Collections (KU). Cresson also listed two male and one female paratopotypes, and we have examined the female allotype, which is a topotypical paratype (KU), and a male, topotypical male paratype (ANSP).

Type locality.

United States. Arizona. Coconino: Bill Williams Forest (35°12'N, 112°12'W).

Other specimens examined from the New World.

UNITED STATES. ARIZONA. Apache: Adamana (34°58.6'N, 109°49.3'W), 12 Jun 1950, A. H. Sturtevant (1♂; USNM). Coconino: Bill Williams Forest (35°12'N, 112°12'W), F. E. Snow (1♂; ANSP). La Paz: Parker (34°09'N, 114°17'W), Jun 1943, W. C. Reeves (1♂; USNM). Navajo: Joseph City (35°57.3'N, 110°20'W), 12 Jun 1950, A. H. Sturtevant (1♂; USNM); Kayenta (36°44.4'N, 110°14.4'W), 14 Apr 2003, W. N. Mathis, T. Zatwarnicki (14♂, 5♀; USNM). Yuma: Yuma (32°43.5'N, 114°37.5'W), 3 Jun-6 Sep 1952, 1953, D. M. Tuttle, Haga (8♂, 14♀; UAR, USNM).

CALIFORNIA. Imperial: Calexico (32°40.7'N, 115°29.9'W), 31 Jul 1958, E. I. Schlinger (3♂, 1♀; UCR); Hot Mineral (33°25.5'N, 115°41.1'W), 25-30 Apr 1952, 1953, J. N. Belkin, W. W. Wirth (12♂, 9♀; LACM, USNM); Palo Verde (33°26'N, 114°44'W), 8 Apr 1949, W. W. Wirth (3♂, 3♀; USNM). Riverside: Thermal (33°38.4'N, 116°08.4'W), 24 Aug 1965, S. Frommer, D. Gerling (1♂; UCR). San Diego: Borrego (33°13.2'N, 116°20.1'W), 2 May 1945, A. L. Melander (1♂; USNM); Borrego Sink (11 km SE Borrego Springs; 33°12.9'N, 116°13.5'W), 14 Sep 1969, J. B. Heppner (1♂, 2♀; FSCA); Palm Spring (33°55.2'N, 116°13.1'W), 21 May 1953, A. L. Melander (1♂; USNM).

COLORADO. Archuleta: Pagosa Springs (37°15.8'N, 107°00.7'W; hot springs), 27 May 1969, W. W. Wirth (1♂; USNM). Moffat: Hells Canyon (9.7 km W; 40°28.3'N, 108°53.7'W), 21 Jun 1946, M. T. James (3♂; UCO). Uintah: Lodore (40°38'N, 108°57.4'W), 23 Jun 1948, M. T. James (1♂; UCO).

IDAHO. Benewah: Chatcolet (47°22.3'N, 116°54.8'W), Aug 1915, A. L. Melander (3♀; USNM). Bonner: Priest Lake (48°34.5'N, 116°57.4'W), 1 Aug 1916, A. L. Melander (1♂, 2♀; USNM). Cassia: Declo (42°31.1'N, 113°37.7'W; on Beta vulgaris), 3 Aug 1931, H. Waters (1♀; USNM).

MONTANA. Glacier: Glacier National Park, St. Mary Lake (48°47.4'N, 113°25.2'W), 2 Aug 1935, A. L. Melander (1♂; USNM). Lake: Ninepipe National Wildlife Refuge (47°26.5'N, 114°07.3'W), 14 Sep 1983. R. S. Zack (1♂; WSU). Lincoln: Troy (48°27.8'N, 115°53.4'W), 29 Jun 1954, A. H. Sturtevant (1♀; USNM). Sheridan: Medicine Lake (48°30.1'N, 104°30.3'W), 9 Jun 1969, W. W. Wirth (1♂; USNM).

NEBRASKA. Sheridan: Hay Springs (42°41'N, 102°41.3'W), 17 Sep 1952, A. H. Sturtevant (1♂; USNM).

NEVADA. Clark: Warm Springs, N. Glendale (36°42.5'N, 114°42.9'W), 18 May 1987, D. E. Hardy (1♂; BYU).

NEW MEXICO. Cibola: Bluewater Lake State Park (35°18.1'N, 108°06.6'W; 2220 m), 9 Aug 2007, D. and W. N. Mathis (5♂, 2♀; USNM). Socorro: Socorro (33°55.9'N, 106°57'W), 1916, S. W. Williston (1♂; ANSP). Valencia: Rio Puerco (34°47.8'N, 106°59.5'W; 1575 m), 9 Aug 2007, D. and W. N. Mathis (2♂; USNM).

TEXAS. Brewster: Big Bend National Park, Boquillas Canyon (29°12.7'N, 102°53.2'W), 20 Jun 1953, W. W. Wirth (1♂, 1♀; USNM). Randall: Palo Duro State Park (34°56'N, 101°39.8'W), 21 Sep 1954, A. H. Sturtevant (1♀; USNM). Jefferson: Fort Davis, near Limpia Creek (30°59'N, 103°88'W), 15 Jul 1963, A. B. Gurney (1♀; USNM).

UTAH. Carbon: Deadman Canyon (16 km NE Price; 39°41.7'N, 110°44'W; 2055 m), 19 Aug 2009, W. N. Mathis (1♂; USNM). Emery: Green River (Green River; 38°59.6'N, 110°08.5'W; 1240 m), 31 Jul 2007, D. and W. N. Mathis (1♂; USNM); Green River (3.3 km N, 39°01.7'N, 110°09.7'W; 1253 m), 30 Jul-16 Aug 2007, 2008, D. and W. N. Mathis (16♂; USNM); San Rafael River (22.5 km SW Green River; 38°55.7'N, 110°24.5'W; 1270 m), 31 Jul 2007, D. and W. N. Mathis (13♂; USNM). Garfield: Boulder Mail Trail/Upper Calf Creek Falls (37°52.3'N, 111°28.3'W), 12 Jul 2000, M. Moody, C. R. Nelson (1♂; BYU); Collet Top Junction, Smoky Mountain Road (37°28.1'N, 111°33'W), 20 Jun 2000, E. C. Green, W. N. Mendel (1♂; BYU); Willow Tank-Hurricane Wash (37°23.2'N, 111°08'W; stock tank), 22 May 2001, D. and W. N. Mathis (1♂; USNM). Grand: Crystal Geyser (14.5 km SE Green River; 38°56.3'N, 110°08.1'W), 15 Aug 2008, D. and W. N. Mathis (7♂; USNM); Swasey Beach (15.3 km N Green River; 39°07'N, 110°06.6'W; Green River; 1255 m), 29 May-15 Aug 2007, 2008, D. and W. N. Mathis (21♂; USNM); Thompson Spring (8.9 km N Thompson Springs; 39°02.3'N, 109°43.4'W; 1740 m), 1-20 Aug 2007, 2008, D. and W. N. Mathis, T. Zatwarnicki (26♂, 2♀; USNM). Kane: Drip Tank Canyon (37°19.4'N, 111°31.8'W), 15 May-6 Jul 2000, 2001, D. and W. N. Mathis, C. R. Nelson (8♂; BYU, USNM); East Fork of Virgin River (26.6 km N Kanab; 37°12.2'N, 112°41.4'W) 18 May 2001, D. and W. N. Mathis (6♂; USNM); Last Chance Creek Junction, Smoky Mountain Road (37°20.8'N, 111°31.6'W; 1920 m), 19 Jun 2000, E. C. Green, W. N. Mendel (2♂; BYU); Sheep Creek (37°29.7'N, 112°04'W), 17 May 2001, D. and W. N. Mathis (2♂; USNM); White House Spring (71 km E Kanab; 37°04.8'N, 111°53.4'W; 1250 m) 19 May 2001, D. and W. N. Mathis (2♂, 1♀; USNM); Willis Creek (37°29'N, 112°05.8'W), 17 May 2001, D. and W. N. Mathis (8♂, 1♀; USNM). Salt Lake: Murray (40°40'N, 111°53.2'W; on celery), 13 Sep 1950, G. F. Knowlton (1♂; USNM). Utah: Goshen Hot Springs (39°57.8'N, 111°51.2'W), 16 Apr 2003, W. N. Mathis, T. Zatwarnicki (5♂, 4♀; USNM). Uintah: Vernal Mountains (40°29.5'N, 109°27'W), 17 Jul 1952, G. E. Bohart, G. F. Knowlton (1♂; USNM).

WASHINGTON. Grant: Columbia National Wildlife Refuge (46°51.1'N, 119°32.2'W), 13 May 1959, H. F. Harwood (1♂; USNM). Pierce: Mt. Rainer National Park, Yakima Park (46°55'N, 121°38'W), 14 Aug 1940, A. L. Melander (1♀; USNM).

WYOMING. Hot Springs: Thermopolis (43°38.8'N, 108°12.6'W), 30 Aug 1940, A. L. Melander (1♂, 5♀; USNM).

Distribution.

(Fig. 32) Nearctic: United States (Arizona, California, Colorado, Idaho, Montana, Nebraska, Nevada, New Mexico, Texas, Utah, Washington, Wyoming).

Remarks.

Like Allotrichoma bezzii , this species occurs in the western United States, although not as far north as Alaska.

Although similar to Allotrichoma sabroskyi , the greatly widened surstylus that bears numerous short setulae easily distinguishes this species from it and all other congeners.