Gabyella mediopalpus

Taxonavigation

Ordo: Diptera
Familia: Sciaridae
Genus: Gabyella

Name

Gabyella mediopalpus unpublished

Type material

Holotype: ♂, 10.07.2016, Malaise trap, leg. Shi Kai, ZFMK-TIS-2602320 in ZFMK

Type locality

China, Zhejiang, Huzhou, Yang Wan Cun, 30.9528 N 119.704 E

Description (male)

Head. Eye bridge 3–4 rows of facets. Antenna unicolour. LW-index of 4^th flagellomere 3–3.3; neck 0.5–0.6 × segment width; transition of basal part to neck pronounced. Colour of neck unicolour. Antennal setae as long as segment width, or longer than segment width; strong; sparse. Palpus darkened; of normal length; palpomeres 3. First palpomere of normal shape; with 5–7 setae; with only sparse sensilla. Second palpomere short and oval. Third palpomere as long as first. Thorax. Colour brown. Notum unicolour. Thoracic setae normal; brown. Posterior pronotum bare. Mesothoracic sclerites bare. Legs. Colour yellow. Hind coxa of same colour as femora. Setae on front coxa black. Front tibial organ as patch of setae; dark; front tibial organ with weakly indicated border. Tibial setae on hind legs weak and inconspicuous. Tibial spurs of equal length. Claws untoothed. Wing. Wing slightly darkened; with weakly developed anal lobe. Wing membrane without macrotrichia. Wing venation weak, with faint stM. M-fork of normal shape. R₁ ending at or slightly before base of m-fork; posterior veins bare; bM bare; r-m bare; bM:r-M 0.65–0.8; st-Cu:bM 0.5–0.7; R₁:R 1.5–1.8; c:w 0.72–0.8. Halter darkened; of normal length. Abdomen. Abdominal setae strong; sparse; on tergites black; on sternites black. Hypopygium concolour with abdomen; LW-index 0.5–0.7. Base of gonocoxites with weak setae; gonocoxites broadly separated; inner margin of gonocoxites typically U-shaped; inner membrane of hypopygium scarcely setose; ventral margin of gonocoxite with short setae. Gonostylus elongate; LW-index 1.8–2.1; Inner margin concave; apex with one obtuse angle. Apical tooth present; without internal structure; of medium strength; LW-Index 1.7–2.7. Awl-like setae long; present beneath apical tooth. Megasetae absent. Whiplash-hair absent. Tegmen 0.5–0.7 × longer than broad; equally rounded; without special features; central process finger-like. Length of ejaculatory apodeme/hypopygium 8–14 %; base of ejaculatory apodeme present. Field with aedeagal teeth clearly visible. Measurements. Body size 3.2–4.1 mm. Hind tibia 1.65–1.85 mm. Wing length 2.8–3.5 mm.

Diagnosis

G. mediopalpus is similar to Gabyella opaca by the partly pear-shaped gonostylus and yellow coxae, but the gonostylus is more slender and the dorso-apical bulge at the gonostylus is less pronounced. A still closer relationship may exist with Gabyella dolichocorpa, which has similarly long antennae and an elongate palpus. However, no finger-like process was mentioned in the original description. Long halters and dark hind and mid coxae are additional distinguishing characters from G. mediopalpus.

DNA Barcoding

COI sequences are assigned to the following BINs:

BOLD:ADK2123 (n=1, K2P: 3.69%)
BOLD:ADD2552 (average distance 1.56%, max. 2.18%, n=3, K2P: 2.59%)
BOLD:AEC4311 (n=1, K2P: 2.59%)

Etymology

The species name refers to the palpus, which is of medium length in contrast to most other species of the genus, which have a shortened palpus.

Discussion

By its COI sequence G. mediopalpus is quite isolated from the remaining congeneric species and probably belongs to a different species complex with Eastern Asian distribution. Morphologically it differs by the more elongate palpus, the fewer basal awl-like setae at the gonostylus and the presence of a finger-like process on the tegmen, which do not exactly fit into the genus description. The species might therefore be regarded as belonging to a distinct subgenus or genus, once this group is better known. Here may also belong the Taiwanese G. dolichocorpa and G. opaca, which was recorded from Russia, very close to the Chinese border. It seems, that G. mediopalus is a complex of cryptic or semi-cryptic taxa, as the few known specimens are assigned to three different BINs. One subspecies is currently recognized, but most probably still more are to be discovered.