Amiota humeralis Loew, 1862

Jones, Lance E. & Grimaldi, David A., 2022, Revision Of The Nearctic Species Of The Genus Amiota Loew (Diptera: Drosophilidae), Bulletin of the American Museum of Natural History 2022 (458), pp. 1-181 : 133-135

Amiota humeralis Loew, 1862

Figures 69C–D , 71 , 72D , 77 , 95C

Amiota humeralis Loew, 1862a: 229 (original description); Malloch and McAtee, 1924: 29 (key and description is male of A. hsui ); Wheeler, 1952: 168 (key to Nearctic species, discussion); Wheeler, 1949: 260 (discussion); Wheeler, 1957: 110 (discussion); Wheeler, 1965: 761 (Nearctic catalog); Brake and Bächli, 2008: 252 (world catalog).

Stegana humeralis (Loew) : Sturtevant, 1921: 57 (comb. nov. by Sturtevant).

Phortica humeralis (Loew) : Malloch, 1921: 312 (comb. nov. by Malloch).

Amiota setigera Malloch, 1924: 51 (original description; type locality: USA, Illinois, Savoy; Deposited in Illinois Natural History Survey , Champaign , Illinois, INHS); Wheeler, 1952: 169 (key to Nearctic species) ; Wheeler, 1957: 110 (discussion); Wheeler, 1965: 761 ( Nearctic catalog) ; Máca, 2003: 265 (redescription and male genitalia figured); Brake and Bächli, 2008: 255 (world catalog); syn. nov.

DIAGNOSIS: Very distinctive, small to medium-sized fly (ThL 1.20–1.29 mm); frons in male narrow, reflective, and silvery (frons in female slightly wider and not as shiny, glossier); hind femur of male with ca. 3–5 long upright setae (females without long dorsoventral setae on femur); inner paraphyses unique, flanking inner lateral margins of the hypandrium, each side with ca. 8–10 thick, heavily sclerotized, feathershaped lobes.

DESCRIPTION: Small to medium-sized fly (ThL 1.20–1.29 mm), dark brown to black, somewhat pollinose, legs yellow. Frons narrow (FL/ FW 0.96–1.25), brilliant silvery from direct anterior view; ocellar triangle black, slightly pollinose. Cheek small, milk white. Palp yellow. Katepisternum lighter in color than rest of pleuron. Hind femur with 3–5 upright setae, more than 2× longer than diameter of femur. Arista: Very long, plumose; longest branch D3; A.R. 0.46; 5 dorsal, 2 ventral branches, none pointed mediad/laterad; arista trunk with medium microtrichia, bare on apical half. Male genitalia: Epandrium not separated dorsally, lower 2/3 with long setae. Cercus long, grading into surrounding membrane and almost continuous with epandrium. Surstylus longer than broad; 7 prensisetae, apices blunt, prensisetae becoming smaller from middle laterally and medially; prominent lateral thumblike lobe extending out and at angle to prensisetae (slightly hooked), creating gap; covered in setulae. Subepandrial sclerite simple, shield shaped, extending dorsally over surstyli, lacking subepandrial appendage. Outer paraphysis large and elaborate, ventral portion laterally flattened, with ca. 13 sensilla, distal portion with an apical claw, bridge arising proximal to apical claw joining to dorsal portion of outer paraphysis; dorsal portion consisting of 2 thickened, heavily sclerotized projections, the apices finely serrated and jagged, the distal end of dorsal portion consisting of a keellike extension with a deep cleft. Inner paraphysis elaborate: flanking inside margin of lateral arms of hypandrium, each half with 8–10 darkly sclerotized, feathershaped appendages branching from the paraphysis stem. Aedeagal apodeme typical, slightly longer than wide, “distal plate” of aedeagal apodeme flared, distal margin slightly concave. Hypandrium simple; incomplete at apex, diameter of consistent thickness, lateral arms not thickened. Ejaculatory apodeme of moderate size, length ~0.4× the depth of epandrium. Head and thorax measurements: (n = 5; Am 183, 324, 465, 656, 737) FL/FW 1.09 (0.96–1.25), EL/EW 1.24 (1.01–1.38), EL/CW 21.58 (17.25–25), FML/ FMW 0.42 (0.31–0.53), PR /RR 0.62 (0.45–0.80), ThL 1.24 (1.20–1.29 mm).

TYPE MATERIAL: Holotype: female: USA: District of Columbia: Loew Coll., “humeralis m.,” “Type 13406,” [barcode] MCZENT00013406, [leg. C. R. Osten-Sacken], [not examined, only photomicrographs reviewed]. Deposited in the Harvard Museum of Comparative Zoology, Cambridge ( MCZC).

OTHER MATERIAL EXAMINED: USA: Alabama: Clay Co., Talladega Nat. For. , 33.443496, -85.839339, 2018-08-15, leg. L.E. Jones, swept around head, 1♀ (Am 923, AMNH) ; Lawrence Co., Bankhead Nat. For. , 434.308325, -87.395084, 2018-08-15, leg. L.E. Jones, swept around head, 1♀ (Am 913, AMNH) ; Wilson Dam F.Q., 1942-07-12, leg. J.N. Belkin, 2♀ (Am 670, 671, LACM) . Arkansas: Johnson Co., Ozark Nat. For. , 35.673036, -93.453114, 2018-08-09, leg. L.E. Jones and J.L. Hughes, swept around head, 2♀ (Am 825, 826, AMNH) ; 2018-08-09, leg. J.L. Hughes and L.E. Jones, swept around head, 1♀ (Am 839, AMNH) ; Logan Co., Magazine Mt. , 2750 ft., 1992-07-06, leg. D. Grimaldi, 1♂ and 7♀ (Am 318, 324*, 327, 330, 344, 359, 360, 363, AMNH) ; Garland Co., Ouachita Nat. For. , 34.540121, -93.352490, 2018-08-09, leg. J.L. Hughes and L.E. Jones, 1♂ (Am 736*, AMNH) . Georgia: Towns-White Cos. , Unicoi Pk., 1954-10-02, leg. H. R. Dodge, 3♀ (Am 411, 413, 414, WSU) . Illinois: Hardin Co., Shawnee Nat. For. , 37.594631, -88.382478, 2018-08-08, leg. L.E. Jones and J.L. Hughes, swept around head, 4♂ and 27♀ (Am 647*, 737*, 738*, 739*, 755–759, 761–765, 767, 768, 770–774, 776, 778, 779, 781–783, 785, 786, 788, 790, AMNH) ; 2018-08-08, leg. J.L. Hughes and L.E. Jones, swept around head, 1♂ and 15♀ (Am 734*, 791, 796–798, 1151–1156, 1158–1162, AMNH) ; Mason Co., Sand Ridge State Park , 1976-06-12, leg. M.E. Irwin, 1♂ (Am 1601*, INHS) ; Savoy , 1916-05- 23, [leg. J. R. Malloch], on sap, INHS Insect Collection 238.815, [Holotype of Amiota setigera Malloch ], 1♂ (no number, INHS) ; St. Clair Co., Stemler Cave Woods Nat. Pres. , 38.464886, -90.155530, 2019-05- 24, leg. L.E. Jones, swept around head, 1♀ (Am 996, AMNH) ; Union Co., Trail of Tears State Forest , 37.499757, -89.340117, 2018-08-08, leg. L.E. Jones and J.L. Hughes, swept around head, 1♂ and 3♀ (Am 807, 808, 811, 813, AMNH) ; 2018-08-08, leg. J.L. Hughes and L.E. Jones, swept around head, 1♀ (Am 820, AMNH) ; White Heath , 1920-08-12, [leg. J. R. Malloch], [paratype of Amiota setigera Malloch ], 1♀ (Am 1612, INHS) ; White Heath , 1920-08-12, leg. J. R. Malloch, INHS Insect Collection 238.814, [Allotype of Amiota setigera Malloch ], 1♀ (no number, INHS) . Indiana: Harrison Co., O’Bannon Woods St. Pk. , 38.194962, -86.267880, 2018-08-14, leg. L.E. Jones, swept around head, 3♂ and 2♀ (Am 655*, 656*, 888, 889, 894, AMNH) ; Perry Co., Hoosier Nat. For. , 38.195597, -86.613230, 2018-08-14, leg. L.E. Jones, swept around head, 1♀ (Am 865, AMNH) . Kansas: Leavenworth , 1935-06-17, leg. L.S. Henderson, 1♀ (Am 450, SEMC) . Mississippi: 8 mi. S. Columbus, 1941-09, leg. G.B. Mainland and R.P. Wagner, 1♀ (Am 70, AMNH) ; Yalobusha Co., George P. Cossar St. Pk., 34.131206, -89.887945, 2018-08-12, leg. J.L. Hughes and L.E. Jones, swept around head, 1♀ (Am 855, AMNH) . Missouri: Carter Co., Ridge Road at Road C, 4.5 mi SW of Van Buren, 1967-08-04, leg. H.B. Leech, 3♀ (Am 382– 384, CAS) ; Franklin Co., Meramac Caverns , 1966- 07-06, leg. P.H. Arnaud Jr., 1♀ (Am 385, CAS) ; Lithium , 1955-06-29, leg., M. R. Wheeler, 1♂ and 7♀ (Am 44, 47–51, 67, 188, AMNH) ; Taney Co., Drury Conservation Area, ex. Buttonbush Pond. , 36 34 2.28 N, 93 4 33.60 W, 280 m, 2019-06-06, leg. B.J. Sinclair, CNC 1450129 , 1♂ (Am 1296, CNC) . Ohio: Lawrence Co., Wayne State Forest , Vesuvius Recreation Area , 1989-07-13, leg. S.A. Marshall, 1♀ (Am 747, DEBU) ; Vinton , 1900-06-05 through 1900-06- 12, [collector unknown], 2♂ and 1♀ (Am 464, 465, 467, SEMC) . Tennessee: Rutledge , 1954-07, leg. M. R. Wheeler, 1♂ (Am 183*, AMNH) . Texas: Austin , 1958-10, leg. L. Throckmorton, 1♀ (Am 109, AMNH) .

DISTRIBUTION: Amiota humeralis inhabits an area comprised of the Ozark Mountains, lower Midwest, portions of the southern Appalachia Mountains , the upper American South , and extends into the Great Plains ; a unique distribution. The holotype of A. humeralis was collected in the District of Columbia, suggesting a greater historical range for this species in the east.

COMMENTS: The name A. humeralis Loew has been misapplied in the literature to many small, dark species of the genus. Wheeler (1952) erroneously cited A. humeralis as the type species of Amiota Loew , which was later amended ( Wheeler, 1957); the type species is A. leucostoma Loew , as designated by Coquillet (1910). The holotype of A. humeralis designated by Loew in the MCZC is a female (fig. 71). Examination of photographs of the holotype revealed a frons on the female that is reflective and golden pruinose. This reflective frons is also found in the male of A. setigera Malloch (type at INHS), although much more brilliant and silvery. Detailed distribution maps of both sexes with shimmering frons overlap and are nearly identical. This morphological and distributional is compelling evidence that the male of A. setigera Malloch is the male of A. humeralis Loew , and that taxonomic conclusion is adopted here. Wheeler (1957) alluded to this possibility as well. Females of A. humeralis are commonly collected, and in some cases, can outnumber the males caught at a given locality by up to 8:1 (L.E.J., personal obs.), so it is no surprise that a female of this species would have been among the first collected and described in the genus. Amiota humeralis exhibits a number of external characters that make its identification easy without the dissection of genitalia including the narrow, silvery frons, as well as the long setae on the hind femora. This species exhibits the characteristic behavior of attraction to the eyes and face common to many Amiota .

Figures

FIG. 69. Heads and lateral views, ungrouped species. A–B. A. floridiensis, sp. nov. (Am 174, holotype, lateral image flipped). C–D. A. humeralis Loew (Am 739). E–F. A. imperator, sp. nov. (Am 562, lateral image flipped).

FIG. 71. Holotype of A. humeralis Loew (MCZC), Museum of Comparative Zoology, Harvard University. Photographs by Charles Farnum. A. Head. B. Lateral view. C. Dorsal view. D. Specimen labels and barcode.

FIG. 72. Aristae, ungrouped species. A. A. barretti (Johnson). B. A. buccata Wheeler. C. A. didens. D. A. humeralis Loew. E. A. floridiensis. F. A. imperator. G. A. laevifurca. H–I. A. sinaloensis. Not to the same scale.

FIG. 77. Male terminalia, A. humeralis Loew. A. Epandrium and cerci. Subepandrial sclerite shaded. B. Ejaculatory apodeme. C. Lateral view of hypandrium and paraphyses. D. Aedeagal apodeme. E. Posterior view of hypandrium and paraphyses. F. Surstyli and subepandrial sclerite, inner view. (Am 324).

FIG. 95. Distribution maps, Ungrouped species. A. A. didens. B. A. floridiensis. C. A. humeralis Loew.