Zygomyia geniculata, 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 : 15

Zygomyia geniculata sp. nov.

( Figs 1F , 7A–E , 20B )

urn:lsid:zoobank.org:act:5D1BA263-35C3-4F28-943E-E8ADF04FFB49

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-4862; one fore leg used for DNA extraction, GenBank accession number: OP747425 ) . PARATYPES: 1 ♂, same as holotype (mounted from alcohol, IZBE); 1 ♂, 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, ZFMK) .

Diagnosis. In having the posteroventral margin of the gonocoxites widely concave and the ventral branch of the gonostylus bi-lobed with lateral non-setose digitate lobe, Z. geniculata resembles Z. flamma . It differs by medial part of the ventral branch of the gonostylus bearing one digitate megaseta (two flame-shaped megasetae in Z. flamma ), and the dorsal branch of the gonostylus anteriorly long, bent medially at right angle (anteriorly short and truncate in Z. flamma ).

Description. Male (n = 2). Body length 2.2–2.4 mm. Wing length, 2.1–2.3 mm; ratio of length to width 2.83– 2.96.

Head. Dark yellow with numerous dark setae. Two ocelli close to eye margins. Clypeus yellow, somewhat lighter than head. Mouth-parts yellow. Palpus with all segments light brown, ratios of three apical segments 1:1.43:2.57. 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 2.0 × as long as broad, apical flagellomere conical, 3.0 × as long as broad basally. Flagellomeres with short yellowish setae.

Thorax. Mesonotum dark yellow. Pleural parts yellow. All bristles and setae on thorax brown. Scutellum with marginal setae, including four strong bristles. Antepronotum with setae, including 4–5 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 4–7 dorsally-directed setae at hind margin. Metepimeron with 4–5 setae on posterior part. Halter yellow. All legs entirely 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 1–2 setae on posterior side apically. Mid femur with 1 apicoventral bristle, hind femur with 3 apicoventral bristles. Mid tibia with 2 a, 4 d (progressively longer towards apex), 1–2 p and 1 v (one additional short seta can present). Hind tibia with 6 a and 4–5 d (progressively longer towards apex). Length ratio of femur to tibia for fore, mid and hind legs: 1.15–1.32, 1.08–1.12, 0.79–0.91. Length ratio of tibia to basitarsus for fore, mid and hind legs: 1.22–1.27, 1.50–1.52, 1.62. Wing membrane with light brownish tinge but without distinct 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 apical half and 1/3, respectively. CuA with 1–2 apical setae on dorsal surface. rm somewhat shorter than m-stem. Costa not extending beyond R 4+5.

Abdomen. Entirely brown. Terminalia ( Figs 7A–E , 20B ) yellow to light brown. Posteroventral margin of gonocoxites smoothly concave. Gonostylus remarkably complex. Ventral branch of the gonostylus somewhat extended transversally, consists of two lobes: (1) ventral lobe large, drawn out posteromedially, with setae at medial margin and group of 3–4 deviating setae at posteromedial corner, (2) lateral lobe digitate, non-setose, (3) ventrally from lateral lobe an apically pointed megaseta arising from prominent basal body that is as long as megaseta. Dorsal branch of the gonostylus large, bent anteriorly at right angle, with (1) setae of different size along posterior margin, (2) pointed megaseta at lateral margin sub-basally, (3) row of 3–4 spines on internal surface laterally, (4) additional digitate, pointed and bent lobe arising from internal surface with mushroom-shaped membranous outgrowth medially, and (5) two pointed megasetae arising from separate basal bodies on internal surface anteriorly. Aedeagus apically membranous, rounded. Parameres broad, with angular apices, extending over aedeagus posteriorly. Gonocoxal apodemes broad, sub-apically bent slightly inward.

Female. Unknown.

Etymology. The specific epithet is Latin, geniculata [like the bent knee], referring to the geniculate dorsal branch of the gonostylus.

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 7. Zygomyia geniculata sp. nov., male terminalia (holotype, MECN-EN-DIP-4862). A, B, ventral view; C, posterior view; D, dorsal view; E, gonostylus, dorsal view. Scale bar = 0.05 mm (A–D) and 0.02 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.