Mythicomyia iskay Sánchez & Evenhuis, 2024, sp. nov.
Creators: name: Sánchez, Pável
name: Evenhuis, Neal
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Mythicomyiidae
Mythicomyia
Mythicomyia iskay

description: Mythicomyia iskay sp. nov.
(Figs 18–37)
Diagnosis. Male. Proboscis shorter than height of eye; anterior ocellus quite larger than posterior ones; middle tibia straight; legs dark brown, except distal apex, yellow; pseudo-surstylus relatively broad, apex somewhat acute in lateral view; anterior arms of parameral sheath characteristically spatulate with straight border (Figs 26–27, 30–31). Female. Scutellum yellow with subtriangular brown suffusion at middle (Fig. 34); posterior margins of tergites narrowly yellow; sperm pump phallus shaped, relatively large, about ⅗ the length of spermathecal reservoir, which is elongate, rod-like, translucent on basal fifth and without glandular trichomes (Figs 36–37).
Description of the male holotype. Length: body, 1.8 mm; wing, 1.3 mm.
Head (Figs 19–20). Predominantly black, gray pruinose; eyes contiguous for 10 facets, separated at vertex by about two times the width of anterior ocellus, this latter quite larger than the posterior ones, ocelli whitish yellow; a pair of setae on ocellar triangle (similar to occipital ones); frons whitish, thin dark line along eye margin (Fig. 19); face whitish, except on the lower margin, dark brown; antenna brown; scape minute, wider than long; pedicel as long as wide; first flagellomere linear lanceolate, about three times as long as pedicel; second flagellomere lanceolate, about half the length of first one, with subbasal stylus (Fig. 21); proboscis brown, short, length beyond oral margin shorter than height of eye; occiput white setose. Thorax (Figs 18, 22). Predominantly dark brown, shining; mesonotum quite humped, as high as half its length, grey pruinose except medially; postpronotal lobe and postalar callus whitish yellow; pleura cinerous pruinose, with whitish yellow markings on narrow margins of anepisternum, upper margins of proepimeron and katepisternum; scattered white setae on mesonotum, postpronotal lobe, anepisternum and scutellum. Legs (Fig. 18). Coxae dark brown; femora dark brown, except narrow apex, yellowish; tibiae yellowish, darker apically; tarsi brownish, except basal two thirds of first tarsomeres, yellowish; pulvilli as long as claws. Wing (Fig. 24). Hyaline, microtrichose; veins yellow; costal vein ending in R 4+5; vein Sc incomplete, ending later than of Rs origin; Rs evanescent at connection with R 1; R 2+3 arising approximately ¾ distance from origin of Rs to r-m crossvein, this latter placed at about ⅐ of dm cell (first portion of M 1+2, before r-m, about half the length of first portion of M 4); vein separating cells br and bm barely evident; cell dm six-sided, almost three times as long as wide; m-m cross vein longer than r-m and about a third the length of dm-m; R 4+5 nearly straight, ending before M 1; M 1 gently curved downward; M 2, M 4 and CuA slightly sinuous; CuP evanescent, little evident; anal lobe developed; haltere whitish, except knob, brown dorsally. Abdomen (Fig. 23). White setose; predominantly dark brown, except on posterior margins of abdominal segments II-VII, with narrow yellowish bands. Terminalia (Figs 25–31). Reddish brown; epandrium elongate, somewhat triangular-shaped with rounded apex in lateral view (Figs. 26–27), semi-circular with scattered setae dorsally in posterior view (Figs 28–29); pseudo-surstylus broad, downward directed, triangular shaped with acute apex in lateral and posterior views (Figs 26–29); cercus triangular-shaped, with scattered setae on the upper half in lateral view (Figs 26–27), somewhat triangular with scattered setae on upper half in posterior view (Figs 28–29); ejaculatory apodeme thickened, broad and rounded in lateral view (Figs 26–27), long and thin in dorsal view (Figs 30–31); lateral ejaculatory process translucid on basal third, with acute apex, gently upward-directed in lateral view, sideways-directed and about half the length of ejaculatory apodeme in dorsal view (Figs 30–31); phallus drop-shaped, distiphallus simple with single apical opening, about a fourth the length of basiphallus; parameral sheath large, approximately half as wide as long, with two tips sideways directed and one tip united posteromedially; anterior arms of parameral sheath elongate, thickened, characteristically spatulate with straight border in lateral view (Figs 26–27); extending before to level of ejaculatory apodeme and more or less parallel in dorsal view (Figs 30–31); gonocoxa subdivided, with a small subtriangular anterior lobe and subrectangular posterior lobe, hollowed in dorsal view (Figs 30–31); gonostylus narrow, with acute apex and downward directed in lateral view, with blunt apex and sideways directed in dorsal view (Fig. 31).
Female (Figs. 32–37). Differs from the male description by the following: Head (Fig. 33). Eyes dichoptic, separated at vertex by about 1.5 times the width of ocellar triangle; anterior ocellus little larger than posterior ones; frons yellowish, except on the upper ¼, dark brown. Thorax (Fig. 34). Mesonotum little humped, predominantly dark brown, except on sides, notopleural and supraalar region broadly yellow (shallowly emarginate above notopleural suture); scutellum yellowish, usually with subtriangular brown suffusion at middle; pleura dark brown, except upper half of anepisternum, upper third of anepimeron, upper third of katepisternum and upper half of meron, yellow. Legs. Femora yellow with mottled brown suffusion. Abdomen (Fig. 35). Tergite I yellow with dark brown spots on sides; posterior yellow margins on remaining tergites comparatively broader than in male. Terminalia (Figs 36–37). Genital fork U-shaped, anterior margin arched with lower margin acute, posterior margin bifurcate, inner arms twice as long as outer ones; sperm pump phallus shaped, cylindrical with conspicuous disc-shaped valve apically and basally, relatively large, about 3/5 the length of spermathecal reservoir and 1.5 times as long as genital fork; proximal spermathecal duct thinner than distal; distal spermathecal duct more than 10 times the length of proximal duct, translucent; three rod-like spermathecal reservoirs, extending to abdominal segment II, elongate, with basal fifth translucent; without glandular trichomes.
Type material. HOLOTYPE. Male: PERU, Lambayeque Prov. 2 km E Zaña; Malaise on dune; ME Irwin, G. Antón Amaya; 12–19.xi.2007; 65 m; 06°56.12’S, 79°34.92’W. Holotype in CAS. PARATYPES. Same data as holotype (11 ♂, 28 ♀); PERU, Amazonas Prov; 22 km W. Pedro Ruiz Gallo at km 271; Malaise in lush old field; ME Irwin, FD Parker; 14–17.xi.2007; 815 m; 5°54.23’S, 78°07.80’ W (3♂); PERU, San Martin Prov; 19 km NE Picota; Malaise along margin of tropical forest in old field; 15–23.xi.2007; ME Irwin, J. Vasquez; 375 m; 7°3.01’S, 76°19.64’W (1 ♂, 2 ♀); PERU, Ancash Prov. 10 km W Huallanca at Yungaypampa; Malaise in dry wash with vegetation; 11-23.xi.2007; ME Irwin, FD Parker; 3190 m; 08°45.49’S, 77°53.42’W (30 ♂, 59 ♀); PERU, Ancash Region; 25 km E Carhuaz, Caseta del Parque Nacional Huascarán; Malaise in dry wash; 14–17.ix.2009 ME Irwin; 3690 m; 09°10.39’S, 77°34.99’W (2 ♀); PERU, Ancash Region; 7 km E Carhuaz, Pampamarca: Malaise across Quebrada Shapshi: 1–13.x.2008; Me Irwin; 3000 m; 09°16.11’S, 77°39.83’W (1 ♂); PERU, Ancash Region; Rt 16, km 78; 10 km W Cajacay, Malaise nr seep in steep cyn; 13–18.ix.2009; ME Irwin; 2050 m; 10°09.07’S, 77°28.67’W (2 ♂, 3 ♀); PERU, Cajamarca Prov; Purhuay Bajo; 13–20.v.2007; Malaise in ravine; ME Irwin, G Antón Amaya; 3250 m; 07°05.38’S, 78°30.96’W (5 ♂, 1 ♀); PERU, Cajamarca Prov; 7 km E Chilete at km 98; Malaise in steep ravine w/ succulent veg; ME Irwin, G. Antón Amaya; 19–23.xi.2007; 1000 m; 07°12.87’S, 78°47.08’W (3 ♀); PERU, Cajamarca [Error, La Libertad] Prov; 13 km E Ciudad de Dios; La Portada de la Sierra; Malaise on dune; ME Irwin, G.Antón A; 22–29.xi.2007; 150 m; 07°19.88’S, 79°22.59’W (1 ♂); PERU, Depto Cajamarca; Nuevo Morero, 7 km S Jaén; dry tropical forest; Malaise in damp wash; ME Irwin; 14–17.xii.2005 770 m; 5°45.38’S, 78°48.11’W (1♂, 1 ♀); PERU. Depto. Cajamarca; 8 km NE Chamaya at km 189; Malaise above wash in tropical sclerophyll veg; ME Irwin; 14–17.xii.2005 500 m; 5°47.48’S, 78°43.53’W (1 ♂); PERU, Cajamarca Prov, Sector La Pampa, Fundo La Paloma, 3 km W Chilete; Malaise in dry gulch; 10–17.v.2007; ME Irwin, G. Antón Amaya; 865 m; 07°13.42’, 78°51.84’W (1 ♀); PERU, Lambayeque Prov; Lambayeque; Malaise on vegetated dunes; 13–20.iv.2006; ME Irwin, G. Antón Amaya; 40 m; 6°42.86’S, 79°54.07’W (4 ♀); PERU, Depto Lambayeque; 8 km E Tupac Amaru; Malaise across steep ravine in dry deciduous forest; 13–17.xii.2005; ME Irwin; 1020 m; 5°55.38’S, 79°33.01’W (1 ♂, 5 ♀); PERU; Depto. Loreto, 3 km S Pampa Hermosa, Yurimaguas; Malaise in oil palms; ME Irwin, G. Anton Amaya; 3- 9.iv.2005; 136 m; 5°55’28.4”S, 76°06’55.9”W (2 ♂); PERU, Piura Dept; 10 m; Sechura; Malaise, stabilized dunes; 28.i–4.ii.2006; ME Irwin, G. Anton Amaya; 05°32.73’S, 80°49.46’W (32 ♂, 18 ♀). Paratypes in CAS (40 ♂, 48 ♀), BPBM (26 ♂, 44 ♀), and MUSM (24 ♂, 35 ♀).
Variation. Both, male and female usually present the knob of the halter black dorsally, but some specimens present halter entirely whitish.
Etymology. The specific epithet is a masculine noun in apposition, iskay is the Quechua word for “two”.
Distribution (Fig. 91). Northern Peru; Amazonas (Bongará), Ancash (Bolognesi, Carhuaz), Cajamarca (Cajamarca, Contumazá, Jaén), La Libertad (Pacasmayo); Lambayeque (Chiclayo, Lambayeque), Loreto (Alto Amazonas), Piura (Sechura), San Martín (Picota)
Remarks. As explained above, in males, this species is similar to M. huk sp. nov. and M. hyalinipennis, being distinguished based on differences in antenna and pseudo-surstylus. By contrast, females of these species are very different, and the most similar species is M. collina (Philippi, 1866), which can be distinguished based on frons coloration (black with lower half yellow vs predominantly yellow with upper ¼ dark brown in M. iskay sp. nov.) and first flagellomere (at least four times longer than scape and pedicel combined vs at most three times as long as scape and pedicel combined in M. iskay sp. nov.). About specimens with halter entirely whitish, males of this species are similar to those of M. orthis Hall, 1976 but can be differentiated based on the epandrium (somewhat triangular-shaped vs somewhat rectangular-shaped in M. iskay sp. nov.) and the characteristically anterior arms of parameral sheath in M. iskay sp. nov., spatulate with straight borders.
description: Published as part of Sánchez, Pável & Evenhuis, Neal, 2024, New Mythicomyia Coquillett, 1893 (Diptera: Mythicomyiidae: Mythicomyiinae) from Peru, pp. 513-538 in Zootaxa 5541 (4) on pages 518-522, DOI: 10.11646/zootaxa.5541.4.5, http://zenodo.org/record/14241264