Zygomyia triseta, 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 : 29-30

Zygomyia triseta sp. nov.

( Figs 2G , 15A–D , 20E )

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Type material. HOLOTYPE ♂, ECUADOR, Napo Province, Yanayacu Biological Station , 0.6164S 77.8831W, alt. 2122 m, 1–3.ix.2019, X. Mengual leg., Malaise trap (mounted from alcohol with terminalia in glycerine, INABIO; specimen code: MECN-EN-DIP-4870; one fore leg used for DNA extraction, GenBank accession number: OP747434 ).

Diagnosis. In having the posteroventral margin of the gonocoxites widely concave and the one-lobed ventral branch of the gonostylus bearing modified megasetae, Z. triseta resembles Z. napoensis . It differs by the sub-quadrate ventral branch of the gonostylus (wider than long in Z. napoensis ), and three modified megasetae anteromedially and posteriorly (one sabre-shaped posterior megaseta in Z. napoensis ). The dorsal branch of the gonostylus is posteriorly bifurcate in Z. triseta (consists of three lobes different in shape and size in Z. napoensis ).

Description. Male (n = 1). Body length 2.9 mm. Wing length 2.6 mm; ratio of length to width 2.50.

Head. Dark yellow with numerous dark setae. Two ocelli close to eye margins. Clypeus yellow, somewhat lighter than head. Mouth-parts yellow to light brown. Palpus with third segment brown, other segments yellow, ratios of three apical segments 1:1.2:3.0. Scape, pedicel and flagellomeres light brown. Flagellomeres cylindrical, first flagellomere 1.86 × as long as broad, fourth flagellomere 1.29 × as long as broad, apical flagellomere 3.0 × as long as broad basally. Flagellomeres with short yellowish setae.

Thorax. Mesonotum dark yellow. Pleural parts yellow with katepisternum somewhat lighter and upper and hind margin of anepisternum and hind margin of laterotergite narrowly brown. All bristles and setae on thorax brown. Scutellum with marginal setae, including four strong bristles. Antepronotum with setae, including 6 bristles of different lengths. Proepisternum with setae including 3–4 stronger bristles. Anepisternum with a number of posteriorly-directed short setae and 5–6 bristles of different lengths on dorsal part. Anepimeron with short setae and 2 bristles on dorsal part. Laterotergite with 5 dorsally-directed setae medially. Metepimeron with 5 setae on posterior part. Halter light brown. Legs yellow, with hind femur apically and dorsally 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 one seta on posterior side apically. Mid femur with 2–3 apicoventral bristles of different size, hind femur with 3–4 apicoventral bristles of different size. Mid tibia with 2 a, 6 d (progressively longer towards apex), 2 p and 3 v. Hind tibia with 8 a, 5 d (progressively longer towards apex) and row of shorter posterodorsal setae. Length ratio of femur to tibia for fore, mid and hind legs: 1.09, 1.11, 0.86. Length ratio of tibia to basitarsus for fore, mid and hind legs: 1.18, 1.41, 1.59. Wing membrane with light brownish tinge and with brown marking over r-m and m-stem. Veins light brown. R 1 and R 4+5 with strong setae on both sides. Crossvein rm and bM-Cu glabrous. Dorsal surfaces of M 1 and M 2 with setae along whole length. CuA with 2–3 setae on dorsal surface apically. M 1 and M 2 discontinue shortly before wing margin. m-stem about as long as r-m. Costa not extending beyond R 4+5.

Abdomen. Entirely brown. Terminalia ( Figs 15A–D , 20E ) yellow. Posteroventral margin of gonocoxites slightly concave, posterior half setose with setae short, of similar size. Ventral branch of the gonostylus small and simple, with (1) anteromedial corner transversally somewhat extended, bearing long hair-like megaseta and 2–3 simple setae, (2) posterior margin with apically blunt, digitate megaseta medially and pointed megaseta more laterally. Dorsal branch of the gonostylus elongated, sparsely setose, posteriorly bifurcate, with (1) group of 3–4 stronger setae at anteromedial margin, (2) lateral prong of posterior furca digitate, bearing setae along lateral margin, (3) medial prong of posterior furca thumb-shaped, with an apical and a medial stronger seta. Aedeagus apically widening, with apical margin retuse. Parameres tapering, apically curved, extending over aedeagus posteriorly. Gonocoxal apodemes evenly wide throughout length.

Female. Unknown.

Etymology. The specific epithet is Latin, triseta [having three setae], referring to the three megasetae on the ventral branch of the gonostylus anteromedially and posteriorly.

Figures

FIGURE 2. Habitus of Zygomyia species from Ecuador (all photos, except Z. bicolor, are taken from holotypes). A, Z. spinosa sp. nov.; B, Z. ximoi sp. nov.; C, Z. bicolor Edwards, 1934 (MECN-EN-DIP-4873); D, Z. uniordata sp. nov.; E, Z. napoensis sp. nov.; F, Z. trilobata sp. nov.; G, Z. triseta sp. nov.; H, Z. talpaeforma sp. nov. Scale bars = 1 mm.

FIGURE 15. Zygomyia triseta sp. nov., male terminalia (holotype, MECN-EN-DIP-4870). A, B, ventral view; C, dorsal view; D, posterior view. Scale bar = 0.1 mm.

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.