Zygomyia ximoi, 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 : 33

Zygomyia ximoi sp. nov.

( Figs 2B , 17A–E , 19C )

urn:lsid:zoobank.org:act:1BB14440-A00B-47B0-A941-525AFDBB79FC

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-4872; one fore leg used for DNA extraction, GenBank accession number: OP747436 ).

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

Description. Male (n = 1). Body length 2.8 mm. Wing length 2.6 mm; ratio of length to width 2.47.

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 segments brown, ratios of three apical segments 1:1.29:2.43. Scape, pedicel and basal half of first flagellomere yellowish, other flagellomeres light brown. Flagellomeres cylindrical, first flagellomere 1.7 × as long as broad, fourth flagellomere 1.5 × as long as broad, apical flagellomere 2.6 × as long as broad basally. Flagellomeres with short yellowish setae.

Thorax. Mesonotum dark yellow. Pleural parts yellow with katepisternum somewhat lighter, upper and hind margin of anepisternum 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 6–7 bristles of different lengths. Proepisternum with setae including 3 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 3 bristles on dorsal part. Laterotergite with 4 dorsally-directed bristles and 6-7 short setae medially. Metepimeron with 3 strong and short setae on posterior part. Halter with stem yellowish, knob 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 strong seta on posterior side apically. Mid femur with 3 apicoventral bristles of different size, hind femur with 5 apicoventral bristles of different size. Mid tibia with 2 a, 5 d (progressively longer towards apex), 2 p and 2 v. Hind tibia with 6 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: 1.17, 1.15, 0.87. Length ratio of tibia to basitarsus for fore, mid and hind legs: 1.25, 1.44, 1.55. 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 with 2–3 setae on dorsal surface apically. m-stem about as long as r-m. Costa not extending beyond R 4+5.

Abdomen. Brown with segments I–II laterally somewhat lighter. Terminalia ( Figs 17A–E , 19C ) yellow to light brown. Posteroventral margin of gonocoxites emarginated, posterior ⅔ setose with all setae of similar size. Ventral branch of the gonostylus sub-quadrate, posteriorly somewhat rounded, posterior marginal area non-setose, otherwise setose with setae at anteromedial corner somewhat stronger. Dorsal branch of the gonostylus contains two lobes separated by transversal cleft: (1) anterior lobe sub-rounded with 3 strong setae along medial margin and one strong seta on ventral surface medially, (2) posterior lobe large, quadrangular, laterally densely setose, with 3 strong setae along medial margin and group of very small spines posteromedially.Aedeagus apically protuberant, rounded. Parameres apically widely conical. Gonocoxal apodemes apically widening, spathulate.

Female. Unknown.

Etymology. The species is named after Dr. Ximo Mengual (Zoological Research Museum Alexander Koenig, Bonn, Germany), the collector of all material of this study.

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 17. Zygomyia ximoi sp. nov., male terminalia (holotype, MECN-EN-DIP-4872). A, B, ventral view; C, dorsal view; D, posterior view; E, gonostylus, dorsal view. Scale bar = 0.05 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.