Amiota leucostoma 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 : 80-83

Amiota leucostoma Loew, 1862

Figures 42A–B , 43 , 44A–B , 45A–B, F–G , 89B

Amiota leucostoma Loew, 1862a: 230 (original description); Coquillet, 1910: 505 (designated as genotype); Sturtevant, 1921: 57

(synonymy under Stegana humeralis ); Malloch and McAtee, 1924: 41, plate VIII, figs. 6–8 (male genitalia figured); Wheeler, 1949: 260–261 (discussion); Wheeler, 1952: 169 (key to Nearctic species); Wheeler, 1965: 761 (Nearctic catalog); Chen, 2004: 66 (inclusion in species group); Brake and Bächli, 2008: 253 (world catalog).

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

DIAGNOSIS Large fly (ThL 1.72–1.94 mm), light brown to light golden-honey in color, abdomen dark brown to almost black, overall coloration similar to A. minor , except with characteristic white markings of genus; outer paraphysis long, swordlike, with small lateral spine 1/3 from apex; inner paraphysis more heavily sclerotized, hooked strongly medially, with small preapical tooth; aedeagal apodeme curved 90° in lateral view, distal end widely flared, with a wide shallow concave depression. Amiota leucostoma is very similar to A. mcalpinei from British Columbia, A. tessae from the Great Lakes region, and A. rufescens (Oldenberg) from Europe, but A. leucostoma can be easily separated by the presence of a lateral spine on the outer paraphysis.

DESCRIPTION: Large fly (ThL 1.72–1.94 mm), light brown to light golden honey, seta black; abdomen dark brown to almost black, legs yellow; coloration similar to A. minor (Malloch) , except with characteristic white markings of genus. Frons light brown, ventral half darker, with numerous scattered black setulae. Cheek yellow on anterior half, whitish yellow on posterior half. Palp yellow. Tergites 1 and 2 lightly colored. Arista: Long, plumose; longest branch D2; A.R. 0.42; 6 dorsal, 3 ventral branches; branches V1 and V2 pointed mediad, D4 pointed laterad; arista trunk with mediumlength microtrichia along much of length. Male genitalia: Epandrium with gap at midline; long setae clustered at ventral portion, ascending to apex. Cercus semicircular. Surstylus pendulous, length greater than twice the width; with 9 pointed prensisetae (not rounded); distal end densely crowded with long setulae. Subepandrial sclerite with a long appendage, ventral to epandrium, the distal end rounded, bent strongly upward. Outer paraphysis long and swordlike; several sensilla pits scattered throughout middle portion; lateral spine 1/3 distance from apex, with sensillum just distal to spine. Inner paraphysis heavily sclerotized, curving strongly medially, with subapical tooth. Aedeagal apodeme bent 90° at midpoint; widely flared on distal end, deeply concave; almost equal in length to the outer paraphysis. Hypandrium deeply notched, web of membrane between hypandrium apex; lateral arms thickened, with a prominent bulging gonopod. Ejaculatory apodeme long, thick, length equal to the epandrium. Head and thorax measurements: (n = 5; Am 379, 399, 1202, 1314, 1319) FL/FW 0.67 (0.61–0.70), EL/EW 1.30 (1.25– 1.36), EL/CW 17.72 (15–19.75), FML/FMW 0.38 (0.37–0.41), PR /RR 0.56 (0.33–0.75), ThL 1.84 (1.72–1.94 mm).

TYPE MATERIAL: Holotype: female: USA: Pennsylvania: Loew Coll., Penn., “leucostoma m.” “Type 13407,” [barcode] MCZ-ENT00013407, [leg. C. R. Osten-Sacken], [not examined, only photomicrographs reviewed]. Deposited in the Harvard Museum of Comparative Zoology, Cambridge ( MCZC).

OTHER MATERIAL EXAMINED: Canada: British Columbia: Cultus Lake , 1948-07-15, leg. H. R. Foxlee, Exp No 12129-13, 1♂ (Am 1313*, CNC) ; 1948- 07-17, leg. H. R. Foxlee, 1♂ (Am 1312*, CNC) . Quebec: Aylmer , 1926-08-12, [collector unknown], 1♂ (Am 1318*, CNC) ; Cottage Beaulieu [location uncertain], 1906-07-07, [collector unknown], 1♂ (Am 1319*, CNC) ; Laniel , 1973-07-24, leg. F.P. Ide, 1♂ (Am 1314*, CNC) ; Old Chelsea, Summit King Mtn. , 1962-06-25, leg. J. R. Vockeroth, 1♂ (Am 1202*, CNC) . USA: Illinois: Urbana , 1916-06-26, [leg. J. R. Malloch], tree trunk, 1♂ (Am 1590, INHS) ; 1916-08-08, [leg. J. R. Malloch], 1♂ (Am 1589, INHS) . Maryland: Pennsylvania: Valley Forge , 1912-07-15, collector unknown, 4♂ (Am 1600*, 1603–1605*, INHS) ; Montgomery Co., Cabin John, 1929-06, leg. F. R Cole , 1♂ (Am 379*, CAS) . Virginia: Blacksburg , 1953-09-09, leg. M. Levitan, 1♀ (Am 297, AMNH) ; Prince William Co., 0.5 km NE Thorofare Gap, vic. Haymarket , 1966-06-25, leg. P.H. Arnaud Jr., 1♂ (Am 399*, CAS) .

DISTRIBUTION: This species is rarely collected and has a large distribution, most records from the Mid-Atlantic and eastern Canada, with one specimen collected as far west as British Columbia. The type locality is in Pennsylvania.

COMMENTS: Amiota leucostoma has long been thought to be synonymous with A. rufescens (Oldenberg) of Europe ( Malloch and McAtee, 1924), but morphology of specimens from various localities reveals consistent differences. The holotype of A. leucostoma was collected in Pennsylvania (fig. 43). Wheeler (1952) erroneously referred to A. humeralis Loew as the type species of the genus, but A. leucostoma Loew was designated as so by Coquillett (1910). It is unknown whether A. leucostoma is attracted to the eyes and face as is common in other Amiota , but this is likely given its presence in another Nearctic member of this species group, A. tessae .

Figures

FIG. 42. Heads and lateral views, A. rufescens species group. A–B. A. leucostoma Loew (Am 399). C–D. A. mcalpinei, sp. nov. (Am 1315, holotype). E–F. A. tessae, sp. nov. (Am 1310, holotype).

FIG. 43. Holotype of A. leucostoma 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. 44. Aristae. A. leucostoma Loew.

FIG. 45. Male terminalia, A. leucostoma Loew. A–B, F–G. A. Ventral view. B. Ejaculatory apodeme. F. Lateral view. G. Surstylus. (Am 379). Male terminalia, A. mcalpinei, sp. nov. C–E, H. C. Ejaculatory apodeme. D. Inner paraphyses. E. Ventral view. H. Hypandrium and gonopod, lateral. (Am 1315, holotype).

FIG. 89. Distribution maps, A. avipes species group. A. A. uniacuminis. A. rufescens species group. B. A. leucostoma Loew. C. A. mcalpinei.