Lygistorrhina woodi, Blagoderov & Ollerton & Whittington, 2023

Blagoderov, Vladimir, Ollerton, Jeff & Whittington, Andrew, 2023, A new species of Lygistorrhina (Lygistorrhina) Skuse, 1890 (Diptera: Keroplatidae, Lygistorrhininae) with a key to the subgenus, Zootaxa 5361 (2), pp. 151-158 : 152-155

Lygistorrhina woodi , sp. nov.

urn:lsid:zoobank.org:act:A9F50BC5-21F7-4DA9-B031-3A52D571B0E7

Material. Holotype: Male. Yemen, Dhi Sufal, alt. 2000m. 20/10/1975. J. R.I.Wood leg. NMS-10018524, (dissected by J. Ollerton from a flower of Ceropegia aristolochioides ssp. deflersiana , [Kew 39277.000]; identified as Lygistorrhina sp. by A. Whittington) .

Description

Male. Measurements ( mm ). Head height 0.27; palpi 0.61; hypopharynx 0.78; proboscis labellum 0.84; thorax length 0.53, thorax height 0.59; coxa 1 0.42; coxa 2 0.32; coxa 3 0.33; wing 1.6 (Sc 0.25, R1 0.73, R5 1,25, width 0.64).

Colouration. Head, preserved part of antennae, thorax and abdomen brown; terminalia slightly darker brown; legs brown except hind femora which are darkened on apical third.

Head rounded, vertex rather flat. Head dichoptic, oval. Ommatidia round, densely set, equal in size. Interommatidial setae stiff and very short, ~½ the diameter of ommatidia. Three ocelli, almost in a straight line, set each on its own mound, lateral facing to the sides, medial facing forward, slightly smaller than lateral. Antenna with pedicel spherical, basal four flagellomeres with length 1.3–1.5× the width, covered with setae 0.5× the width of flagellomeres, with two longer apical dorsal setae. Face narrow. Clypeus pointed at apex, its length 1.8× the width. Palpi long, 0.7× the length of proboscis, tapering, with long setae along entire surface. Proboscis evenly curved caudally, its length 2× the length of fore coxa, and 3× the head height.

Thorax. Scutum evenly covered with short setae, with longer supraalar setae. Scutellum short, without long setae. Antepronotum with three setae, proepisternum with 5 setae; suture between them indistinct. Ventral margin of preepisternum 2 widely rounded. Posterior margin of metepisternum longer than anterior, not extending to the level of laterotergite. Laterotergite with an irregular posterior row of 6–8 setae. Mediotergite very convex.

Wing hyaline, moderately wide, costal margin slightly convex. Microtrichia on membrane moderately long (0.01 mm), overlapping. Costa with long setae, ending at half distance between R 5 and M 1. Sc short, 0.25 mm, ending at C. R 1 straight, 0.73 mm. R 5 slightly sinusoid, both R 1 and R 5 with long setae (0.04 mm) dorsally and ventrally. Crossvein r-m indistinct. M 1 and M 2 almost straight, the base of their fork is reduced, M 2 begins more proximally than M 1. M 3+4 and CuA evenly curved caudally, slightly diverging. CuA ends distad of the level of R 1 tip.

Legs. Fore coxa is the longest, mid coxa a little shorter. Tibial and tarsal setae not in rows. Fore basitarsus shorter than fore tibia. Number of tibial spurs on fore, mid and hind tibia 1:2:2, mid tibia tibial spurs ca. 1.5× the tibia diameter, hind tibial spurs 2.5× (outer) and 2× (inner) the maxumum tibia diameter. Hind tibia slightly expanded apically. Mid tarsal claws straight, sharply pointed.

Abdomen unicolorous, irregularly covered in setae, sternite 1 bare. Terminalia slightly darker than abdomen. Tergite 9 roughly triangular with rounded apex and shallow sinus at the base, length 0.12 mm, width 0.09 mm, with long scattered setae and a dense patch of short spines at apex. Cerci triangular. Apodeme of tergite 9 with long, narrow stalk, and two short thin arms directed apically. Gonocoxites fused ventrally, with a deep incision, almost reaching the base of synsclerite. Synsclerite length and width 0.15 mm. Gonostyli simple, length 0.12 mm, with a strong pointed dorsoapical tooth and dense patch of ventroapical setae. Long flagellate setae on mediodorsal edge of gonostylus absent. Aedeagus with flat apex.

Diagnosis.

Lygistorrhina woodi sp. nov. is unique among other species of the subgenus in having compound eyes with very short interommatidial setae, proboscis relatively short; costa reaching only ~½ of distance between R 5 and M 1; and tergite 9 of male terminalia with shallow sinus basally and very small arms of apodeme.

Etymology

The specific epithet is a patronym for John R. I. Wood, a prominent botanist, who inadvertently collected the holotype of the species.