Zygomyia longistyla, Kurina & Õunap, 2023

Kurina, Olavi & Õunap, Erki, 2023, Morphological and molecular data reveal fifteen new sympatric Zygomyia Winnertz, 1864 (Diptera: Mycetophilidae) species from Ecuador, Zootaxa 5227 (1), pp. 1-49 : 16-18

Zygomyia longistyla sp. nov.

( Figs 1B , 8A–E , 20C )

urn:lsid:zoobank.org:act:8D19D9C1-674B-4EC0-AD9B-6A2C6A563E19

Type material. HOLOTYPE ♂, ECUADOR, Napo Province, Yanayacu Biological Station , 0.5956S 77.8942W, alt. 2234 m, 29.viii–3.ix.2019, X. Mengual, T. Salden leg., double Malaise trap (mounted from alcohol with terminalia in glycerine, INABIO; specimen code: MECN-EN-DIP-4863; one fore leg used for DNA extraction, GenBank accession number: OP747426 ) . PARATYPES: 2 ♂♂, same as holotype (1 ♂, mounted from alcohol, IZBE; both hind legs used for DNA extraction, GenBank accession number: OP747427 ; 1 ♂, mounted from alcohol, ZFMK) .

Diagnosis. By distinct wing markings and exceptionally long ventral branch of the gonostylus, Zygomyia longistyla is similar to Z. ornatipennis Lane, 1948 , known from Brazil (São Paulo) and Argentina (Misiones) (distribution by Oliveira and Amorim 2014; figures of male terminalia Lane 1948, figs 5, 35, 42). However, the new species has haltere entirely yellow (with yellow stem and blackish knob in Z. ornatipennis ), the ventral branch of the gonostylus 15 times as long as wide (less than 10 times as long as wide in Z. ornatipennis ), the dorsal branch of the gonostylus with a broad hatchet-shaped posterior lobe (without such lobe in Z. ornatipennis ) and aedeagal complex bell-shaped (more parallel-sided in Z. ornatipennis ).

Description. Male (n = 2). Body length 4.4–4.6 mm. Wing length 3.9–4.0 mm; ratio of length to width 2.89–3.05.

Head. Dark yellow with numerous dark setae. Two ocelli close to eye margins. Clypeus yellow, somewhat lighter than head. Mouth-parts yellow. Palpus with 1 st segment light brown, 2 nd –4 th segments dark brown, 5 th segment pale yellow, ratios of three apical segments 1:1.27:2.27. Scape, pedicel and basal half of first flagellomere yellow, other flagellomeres light brown. Flagellomeres cylindrical, first flagellomere 2.4 × as long as broad, fourth flagellomere 1.87 × as long as broad, apical flagellomere conical, 3.1 × as long as broad basally. Flagellomeres with short yellowish setae.

Thorax. Mesonotum dark yellow. Pleural parts yellow, fore margin of anepimeron and hind margin of laterotergite brown. All bristles and setae on thorax brown. Scutellum with marginal setae, including four strong bristles. Antepronotum with setae, including 6–8 bristles of different lengths. Proepisternum with setae including 4–5 stronger bristles. Anepisternum with a number of posteriorly-directed short setae and 7–11 bristles of different lengths on dorsal part. Anepimeron with few short setae and 4 bristles on dorsal part. Laterotergite with setae and 8–9 dorsally-directed bristles on dorsal half. Metepimeron with numerous short setae. Halter yellow.All legs yellow except hind femur, mid and hind tibia apically brown. Tarsi appear darker, due to dense brown setation. Whole anterior side of fore coxa, apical fourth of anterior side of mid coxa and all femora clothed in dark setae. Hind coxa with 2–3 setae on posterior side apically. Mid femur with 2–3 and hind femur with 3-4 apicoventral bristles. Mid tibia with 3–4 a, 5 d, 1 p and 1 v (one additional short seta can present). Hind tibia with 9 a and 5 d. Length ratio of femur to tibia for fore, mid and hind legs: 1.26, 0.95–1.0, 0.82. Length ratio of tibia to basitarsus for fore, mid and hind legs: 1.0, 1.23–1.43, 1.49–1.54. Wing membrane with distinct markings: apical part widely infuscated, central band wide, extending from fore margin to M 2. Veins light brown. R 1, R 4+5 and crossvein rm with strong setae on both sides. bM-Cu and m-stem glabrous. Dorsal surfaces of M 1, M 2 and CuA with 2–6 setae apically. rm about two times as long as m-stem. Costa not extending beyond R 4+5.

Abdomen. Brown, with first five segments with large yellow triangular lateral areas. Terminalia ( Figs 8A– E , 20C ) yellow. Posteroventral margin of gonocoxites with emarginated flange. Ventral branch of the gonostylus exceptionally elongated, about 15 times as long as wide, setose, with apical strong, medially directed seta deviating from other setosity. Dorsal branch of the gonostylus largely membranous, complex, with (1) broad hatchet-shaped posterior lobe bearing digitate, pointed sub-lobe at posterior margin, (2) medial setose small lobe, and (3) anterior hook-shaped lobe. Aedeagal complex bell-like. Parameres widest medially, extending over aedeagus posteriorly. Gonocoxal apodemes short, club-shaped.

Female. Unknown.

Etymology. The specific epithet is derived from Latin, longus [long] and stylus [stylus], referring to the exceptionally long gonostylus that is more than twice as long as the gonocoxite.

Figures

FIGURE 1. Habitus of Zygomyia species from Ecuador (all photos are taken from holotypes). A, Z. diversiseta sp. nov.; B, Z. longistyla sp. nov.; C, Z. flamma sp. nov.; D, Z. acrotricha sp. nov.; E, Z. paniculata sp. nov.; F, Z. geniculata sp. nov.; G, Z. pectinella sp. nov.; H, Z. comata sp. nov. Scale bars = 1 mm.

FIGURE 8. Zygomyia longistyla sp. nov., male terminalia (holotype, MECN-EN-DIP-4863). A, B, D ventral view; C, dorsal view; E, gonostylus, dorsal view. Scale bar = 0.2 mm (A), 0.1 mm (B–D) and 0.05 mm (E).

FIGURE 20. Aedeagal apparatus of Zygomyia species from Ecuador (all photos, except Z. bicolor, are taken from holotypes). A, Z. comata sp. nov.; B, Z. geniculata sp. nov.; C, Z. longistyla sp. nov.; D, Z. bicolor Edwards, 1934 (MECN-EN-DIP-4873); E, Z. triseta sp. nov.; F, Z. talpaeforma sp. nov. Scale bar = 0.1 mm.