Nymphomyia aijuanae Makarchenko et Tang, 2024

Makarchenko, Eugenyi A. & Tang, Hongqu, 2024, Nymphomyia aijuanae sp. nov. - a new species of archaic nymphomyiids (Diptera: Nymphomyiidae) from Oriental China, Zootaxa 5424 (1), pp. 145-150 : 145-149

Nymphomyia aijuanae Makarchenko et Tang , sp. nov.

http://zoobank.org/NomenclaturalActs/ 9526CE0B-557F-4830-B5F8-F06F811A886A

( Figs 1–12 )

Type material. Holotype, CHINA: Fujian Province, Wuyi Mountain National Park, Tongmu Village , swept at the dawn over a bridge across a small stream, 05.VIII.2014, leg. Hongqu Tang. Paratypes: 4 adult males, 3 adult females, the same data as holotype .

Derivatio nominis. The species epithet aijuanae recognizes HQ’s former student Aijuan Liao from University of Lausanne who transported the type material from Asia to Europe during the pandemic era.

Description

Adult male (n=5, except when otherwise stated). Pale grey, weak chitinized. Total length 1.61–1.86 mm. Total length/ wing length 1.30–1.67.

Head 140–164 µm long and 118–140 µm wide, gradually narrowed anteriorly and ends rostrum ( Figs. 1, 3 ), which truncate, dorsally with 3–4 pairs of setae. Compound eyes with microtrichiae, on the dorsal side of the head are wide apart ( Fig. 1 ), distance between them in 2.2–2.3 times width of the end of rostrum. Ommatidia of compound eyes contiguous ventrally, contact between three pairs of facets ( Fig. 3 ). Antenna 122–134 µm long, with two rounded basal segments, 1 st segment 28–33 µm long, 2 nd segment 18 µm long, 3 rd segment long (82–88 µm), slightly extended to the top, with apical terminal sensilla 9 µm long ( Fig. 2 ); antenna 0.74–0.82 times shorter than head. Labium as in Figs 3, 6 , laterally without setae.

Thorax length 0.40–0.46 mm, which carrying a pair of boomerang-shape wings, halteres and 3 pairs of legs; wing length 1.15–1.31 mm, maximum width 0.15–0.16 mm, with reduced venation, on the edge with whip-shape setae 0.21– 0.30 mm long; halteres 0.16 mm long. Empodium of foretarsus short, not extending beyond apex of tarsal claws; claws with prominent basal tooth ( Fig. 5 ). Structure of legs and thorax are the same as N. alba described in detail by Tokunaga (1935).

Terminalia ( Figs 4 , 8, 10–12 ). Abdomen 1.2–1.4 mm long. Segment VII with pair of small tubercules in anterolateral part, 6–8 µm long. Tergite VIII in posterolateral angles with patch of short setae. Segment VIII anterolaterally with 2 pairs of short paratergal projections. First pair as bare small protrusions in the form of tubercles, 16 µm long. Second pair in form of rounded triangular projections covered with short strong setae, 28–32 µm long ( Fig. 8 ). Last abdominal segment dorsally with cerci, in ventral side with of gonocoxites, gonostylus and aedeagus; gonocoxites and cerci fused indistinctly. Сerci distally expanded, ending in two finger-like projections. Aedeagus length of 68–70 µm long, with straight or slightly concave apex ( Fig. 4 ). Gonostylus with two branches—bare sickle-shaped, 44–68 µm long and serrate elongated, 52–72 µm long, slightly curved, with numerous setae along the inner edge ( Figs 4 , 8 ); gonostylus is folded at rest ( Figs 4 , 8 ), and straightens out during flight and copulation (expanded state) ( Figs 10–12 ).

Adult female (n = 3, except when otherwise stated) in general similar to male. Total length 1.67–1.84 mm. Total length/wing length 1.47–1.60.

Head length 131–157 µm, width—130–132 µm. Compound eyes with microtrichiae, on the dorsal side of the head are wide apart. The distance between the compound eyes dorsally 2.3–2.5 times the width of the end of the rostrum. Ommatidia of compound eyes contiguous ventrally, contact between three pairs of facets. Antenna 122–148 µm long; antenna 0.93–0.95 times shorter than the head.

Thorax length 0.40 mm. Wing length 1.13–1.15 mm, maximum width 0.15–0.16 mm. Edge with whip-shape setae 0.21–0.30 mm long; halteres 0.18 mm long.

Terminalia ( Figs 7 , 9 ). Segment VII with pair of small tubercules in anterolateral part. Segment VIII with pair of small lateral paratergal projection 8–12 µm long. Tergite VIII in posterolateral angles with patch of short setae. Sternite VIII posterolaterally with pair of wedge-shaped projections 30–32 µm long. Sternite IX median process elongated, with a rounded top, 44 µm long. Sternite IX lateral processes wide triangular, 34–36 µm long. Сerci distally expanded, ending in narrow projection, at top of which there is seta 12–16 µm long.

Diagnosis. Adult (male and female). Rostrum truncate, dorsally with 3–4 pairs of setae. Compound eyes with microtrichiae, ommatidia contiguous ventrally, contact between three pairs of facets. Antenna 0.74–0.82 times shorter than head, with one apical terminal sensilla. Labium laterally without setae. Empodium of foretarsus short, not extending beyond apex of tarsal claws; claws with prominent basal tooth.

Male terminalia. Segment VII with pair of small tubercules in anterolateral part. Tergite VIII in posterolateral angles with patch of short setae. Segment VIII anterolaterally with 2 pairs of short paratergal projections, from which first pair as bare small protrusions in the form of tubercles, second pair in form of rounded triangular projection covered with short strong setae. Сerci distally expanded, ending in two finger-like projections. Aedeagus with straight or slightly concave apex. Gonocoxites fused broadly to cerci. Gonostylus with two branches—bare sickle-shaped, sclerotized one, and serrate, elongated, slightly curved another, with numerous setae along the inner edge; gonostylus is folded at rest and extends out (expanded state) during flight and copulation.

Female terminalia. Segment VII with pair of small tubercles in anterolateral part. Segment VIII with pair of small lateral paratergal projections. Tergite VIII in posterolateral angles with patch of short setae. Sternite VIII posterolaterally with pair of wedge-shaped projections. Sternite IX median process elongated, with rounded top. Sternite IX lateral processes wide triangular. Сerci distally expanded, ending in narrow projection, at top of which there is seta.

Adults of a new species are closely related to N. holoptica from Hong Kong. Males of both species have bifurcate gonostylus, but N. holoptica with branches of gonostylus which similar shape as curved lobes and same sizes. Segment VIII anterolaterally with one pair of short paratergal projections in form of tubercles. N. aijuanae sp. nov. with branches of gonostylus of different sizes and lengths. One branch bare sickle-shaped, second branch more long, elongated, slightly curved, with numerous setae along the inner edge. Segment VIII anterolaterally with 2 pairs of short paratergal projections, from which first pair (ventral one) as bare small protrusions in the form of tubercles, second pair in form of rounded triangular projections covered with short strong setae. Females separate in different shapes and sizes of cerci, structure of sternites VIII–IX and tergite VIII. So, sternite VIII of new species posterolaterally with pair of wedge-shaped projections which are absent in N. holoptica .

Ecology and distribution. Adults were collected near a small stream in Wuyi Mountain National Park, Tongmu Village of Fujian Province ( Figs 13–14 ), located at an altitude of about 800 m a.s.l., with water temperatures 11.1–12.5 °C, conductivity 9.0–13.5 µS/cm, pH 6.45–6.95; substrate of stream bed is mainly some cobble and pebble.

Figures

FIGURES 1–7. Adult male (1–6) and female (7) of Nymphomyia aijuanae sp. nov. 1, head in dorsal view; 2, antenna; 3, head in ventral view; 4, 7, terminalia in ventral view; 5, fore-tarsal claw; 6, rostrum and labium in ventral view. ae—aedeagus; ce— cerci; gs—gonostylus; pp—paratergal projections; sp—sternite IX median process; lp—sternite IX lateral process; ts—terminal antennal sensilla; R—rostrum; L—labium. Scale bar for Figs 1, 4, 6–7—50 μm; for Figs 2, 5—20 μm.

FIGURES 8–12. Adult male (8, 10–12) and female (9) of Nymphomyia aijuanae sp. nov. 8, terminalia with gonostylus in folded state; 9, terminalia in ventral view; 10, gonostylus in expanded state, lateral view; 11–12, terminalia with gonostylus in expanded state, ventral view. Abbreviations are the same as in Figs 1–7.

FIGURES 13–14. Locality of Nymphomyia aijuanae sp. nov. CHINA: Fujian Province, Wuyi Mountain National Park, Tongmu Village, unnamed stream (Photos by Hongqu Tang).