Zygomyia trilobata, 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 : 27-29

Zygomyia trilobata sp. nov.

( Figs 2F , 14A–E , 19E )

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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-4869; one fore leg used for DNA extraction, GenBank accession number: OP747433 ).

Diagnosis. In having the posteroventral margin of the gonocoxites widely emarginated and the one-lobed ventral branch of the gonostylus without modified megasetae, Z. trilobata resembles Z. ximoi . It differs by the ventral branch of the gonostylus being wider than long (longer than wide in Z. ximoi ), and the dorsal branch of the gonostylus having large, medially rostrum-shaped lobe with a row of small spines medially (dorsal branch of the gonostylus has large, medially truncated lobe with a row of small spines posteromedially in Z. ximoi ).

Description. Male (n = 1). Body length 2.7 mm. Wing length 2.4 mm; ratio of length to width 2.58.

Head. Brown with numerous dark setae. Two ocelli close to eye margins. Clypeus yellow, somewhat lighter than head. Mouth-parts yellow to light brown. Palpus with segments brown, ratios of three apical segments 1:1.43:2.43. Scape, pedicel and basal half of first flagellomere yellowish, other flagellomeres light brown. Flagellomeres cylindrical, first flagellomere 2.2 × as long as broad, fourth flagellomere 1.4 × as long as broad, apical flagellomere 3.14 × as long as broad basally. Flagellomeres with short yellowish setae.

Thorax. Mesonotum dark yellow. Pleural parts yellow with katepisternum somewhat lighter. All bristles and setae on thorax brown. Scutellum with marginal setae, including four strong bristles. Antepronotum with setae, including 5–6 bristles of different lengths. Proepisternum with setae including 2 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 7–8 dorsally-directed setae medially. Metepimeron with 3 setae on posterior part. Halter light brown. Legs yellow. 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 apicoventral bristles of different size, hind femur with 4 apicoventral bristles of different size. Mid tibia with 2 a, 5 d (progressively longer towards apex), 3 p and 2 v. Hind tibia with 6 a, 5 d and row of shorter posterodorsal setae. Length ratio of femur to tibia for fore, mid and hind legs: 0.97, 1.10, 0.88. Length ratio of tibia to basitarsus for fore, mid and hind legs: 1.19, 1.56, 1.50. Wing membrane with light brownish tinge, without markings. 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 devoid of setae on dorsal surface. m-stem about as long as r-m. Costa not extending beyond R 4+5.

Abdomen. Brown with segments I–IV laterally somewhat lighter. Terminalia ( Figs 14A–E , 19E ). Yellow to light brown. Posteroventral margin of gonocoxites emarginated. Posterior half of gonocoxite setose with posteromedial setae somewhat stronger. Ventral branch of the gonostylus simple, sub-rounded, transversally extended, setose. Dorsal branch of the gonostylus with three lobes of different size: (1) anterior lobe digitate, setose, (2) medial lobe rostrum-shaped, laterally setose, medial margin with row of small spines and one sub-apical seta on dorsal surface, and (3) posterior lobe short and wide, posteromedially angular, non-setose. Aedeagus apically blunt. Parameres broad, apically angular. Gonocoxal apodemes apically widening, spathulate.

Female. Unknown.

Etymology. The specific epithet is Latin, trilobata [having three lobes], referring to the three-lobed dorsal branch of the gonostylus.

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 14. Zygomyia trilobata sp. nov., male terminalia (holotype, MECN-EN-DIP-4869). A, B, ventral view; C, posterior view; D, dorsal view; E, gonostylus, dorsal view. Scale bar = 0.1 mm (A–D) and 0.02 mm (E).

FIGURE 19. Aedeagal apparatus of Zygomyia species from Ecuador (all photos are taken from holotypes). A, Z. acrotricha sp. nov.; B, Z. pectinella sp. nov.; C, Z. ximoi sp. nov.; D, Z. flamma sp. nov.; E, Z. trilobata sp. nov.; F, Z. napoensis sp. nov. Scale bar = 0.1 mm. Abbreviations: aed = aedeagus, gc ap = gonocoxal apodeme, par = paramere.