Trichosiopsis transatlantica

Taxonavigation

Ordo: Diptera
Familia: Sciaridae
Genus: Trichosiopsis

Name

Trichosiopsis transatlantica unpublished

Type material

Holotype: ♂, 04.06.2014, Sweep netting, leg. Olsen & Gammelmo, bf-sci-00367 in NHMO

Type locality

Norway, Buskerud, Gol

Description (male)

Head. Eye bridge 4–5 rows of facets. Antenna unicolour. LW-index of 4^th flagellomere 1.45–2; neck 0.22–0.32 × segment width; transition of basal part to neck pronounced. Colour of neck unicolour. Antennal setae shorter than segment width; fine; dense; salient. Palpus darkened; long; palpomeres 3. First palpomere elongate; with 3–5 setae; with only sparse sensilla. Second palpomere elongate. Third palpomere as long as first. Thorax. Colour bright brown. Notum unicolour. Thoracic setae long and strong, or normal; brown. Posterior pronotum setose. Postpronotal setae 3–4; fine. Mesothoracic sclerites bare. Legs. Colour yellow. Hind coxa of same colour as femora. Setae on front coxa pale. Front tibial organ as patch of setae; dark; front tibial organ not bordered. Tibial setae on hind legs normal, shorter than tibial width. Tibial spurs of equal length. Claws untoothed. Wing. Wing slightly darkened; of normal shape. 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 with macrotrichia; stM mostly with macrotrichia, or with a few macrotrichia; CuA₁ and CuA₂ mostly with macrotrichia; bM bare; r-m mostly setose; bM:r-M 0.5–0.7; st-Cu:bM 0.6–0.8; R₁:R 1.25–1.45; c:w 0.69–0.77. Halter darkened; of normal length. Abdomen. Abdominal setae dense; on tergites brown, or white; on sternites white. Hypopygium concolour with abdomen; LW-index 0.51–0.71. Base of gonocoxites with weak setae; gonocoxites broadly separated; inner margin of gonocoxites narrowly U-shaped; inner membrane of hypopygium scarcely setose; ventral margin of gonocoxite with short setae, or with elongate setae. Gonostylus elongate; LW-index 2.3–2.52; Inner margin concave; apex equally rounded. Apical tooth present; without internal structure; of medium strength; LW-Index 2–3. Awl-like setae normal; present beneath apical tooth. Megasetae absent. Whiplash-hair absent. Tegmen 0.55–0.7 × longer than broad; rectangular with rounded edges, or of unusual shape; without special features; central process absent. Length of ejaculatory apodeme/hypopygium 26–34 %; base of ejaculatory apodeme present. Field with aedeagal teeth inconspicuous. Measurements. Body size 2.4–3 mm. Hind tibia 1.4–1.6 mm. Wing length 2.1–2.7 mm.

Diagnosis

By the bright body hairs and the saddle-shaped tegmen, Trichosiopsis transatlantica belongs to the Trichosiopsis subcoarctata complex. It is most similar to Trichosiopsis indistincta. Both species differ only in nuances. So, Tr. transatlantica is a little bit smaller than its sister species, has a more elongate gonostylus and the hairs on the abdomen are usually brighter.

DNA Barcoding

The COI sequences are assigned to two different BINs:

BIN BOLD:ACC2550 (average distance 0.09%, max. 0.36%, n=12, K2P: 3.91%)
BIN BOLD:AAP9893 (average distance 0.2%, max. 1.26%, n=19, K2P: 3.91%)

Etymology

lat. trans = over. The name refers to the fact, that the species is present on both sides of the Atlantic: “crossing the ocean”.

Discussion

This is a case of cryptic or semi-cryptic species with Tr. indistincta, detected by DNA barcoding. Both sibling species occur from Central to Northern Norway. Based on the currently known range of Tr. transatlantica does not reach so far northern as Tr. indistincta.