Difference between revisions of "Trichosiopsis claviforceps"

Latest revision as of 18:18, 1 January 2021

Taxonavigation

Ordo: Diptera
Familia: Sciaridae
Genus: Trichosiopsis

Name

Trichosiopsis claviforceps (Tuomikoski, 1960) – Wikispecies link – ZooBank link

• Trichosia (Leptosciarella) claviforceps Tuomikoski, 1960^[1]: 25, fig. 5b
• Leptosciarella (Leptosciarella) claviforceps (Tuomikoski, 1960)^[2]: 78, fig. 27

Type material

Holotype: ♂, 04.07.1958, leg. Tuomikoski, in MZH

Type locality

Finland, Kuusamo, Oulankajoki

Material studied

Finland: 1 ♂, Le, Enontekiö, Annjaloannji, Malaise trap, Jussila, 11.-15.07.2007, MZH 9206; 1 ♂, Li, Inari, Tsarmi puro 2, Malaise trap, Salmela, 27.08.2004, MZH 9207; 2 ♂, Le, Kilpisjärvi, Jakovlev & Penttinen, 2006, MZH 9205/9246; 3 ♂, Tb, Kolari, Konnevesi, Korpi jakso 9, Penttinen, MZH 9202-9204; 2 ♂, Kuusamo, Ks, Saaripuro, Malaise trap, Salmela, 03.05.2005, MZH 9200/9201; 1 ♂, Ks, Raatepuro, Malaise trap, Salmela, 03.08.2005, MZH 9347; Norway: 3 ♂, Varangerhalbinsel, Finmark, Vadsö, Laubwald, Birke, Zwergsträucher, exhaustor, Jaschhof, 12.07.1994, PWMP 1792-1794; Russia: 1 ♂, Jushnyi Yamal, Olschwang, 25.07.1981, PWMP 1791; Sweden: 1 ♂, Lule lappmark, Kabdalis, Norrbottens län, Suorke Reserve, swamp forest (spruce, birch aspen), Malaise trap, Viklund, 31.5.-23.09.1983, NHRS 282; 3 ♂, Pite lappmark, Arjeplog, Norrbottens län, L. Sädvajaure (northern end); subalpine birch forest, Malaise trap, Jaschhof & Jaschhof, 7.7.-12.08.2005, NHRS 997/1157, PKHH 5864; 6 ♂, Torne lappmark, Nikkaluokta, Norrbottens län, young birch/willow forest along stream, Malaise trap, Jaschhof & Jaschhof, 14.7.-05.08.2005, PKHH 5941, NHRS 1061/1074, ZSMC 2407/2408.

Description (male)

Head. Eye bridge 4 rows of facets. Antenna unicolour. LW-index of 4^th flagellomere 1.8–2.3; neck 0.19–0.28 × segment width; transition of basal part to neck pronounced. Colour of neck unicolour. Antennal setae shorter than segment width; of normal strength; sparse; salient. Palpus darkened; of normal length; palpomeres 3. First palpomere of normal shape; with 3–5 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 setose. Postpronotal setae 2–3; 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; pale; 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, or 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, or ending clearly before base of m-fork; posterior veins with macrotrichia; stM with a few macrotrichia, or bare; CuA₁ and CuA₂ bare; bM bare; r-m with few setae; bM:r-M 0.61–0.81; st-Cu:bM 0.25–0.4; R₁:R 0.9–1.2; c:w 0.58–0.7. Halter darkened, or pale; of normal length. Abdomen. Abdominal setae weak; on tergites black; on sternites white. Hypopygium concolour with abdomen; LW-index 0.55–0.67. Base of gonocoxites with weak setae; gonocoxites narrowly 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 2.4–2.6; Inner margin straight, or concave; apex equally rounded. Apical tooth present; without internal structure; of medium strength; LW-Index 3–4. Awl-like setae normal; present beneath apical tooth. Megasetae absent. Whiplash-hair absent. Tegmen 0.4–0.6 × longer than broad; rectangular with rounded edges; with dark and strengthended edges; central process absent. Length of ejaculatory apodeme/hypopygium 15–25 %; base of ejaculatory apodeme absent. Field with aedeagal teeth inconspicuous. Measurements. Body size 2.5–3 mm. Hind tibia 1.07–1.27 mm. Wing length 2.6–3 mm.

Diagnosis

Trichosiopsis claviforceps has an apically broadened (clavate) gonostylus, as the species name indicates. It is also characterized by the general absence of macrotrichia on the posterior wing veins. However, contrary to the original description there are a few isolated macrotrichia on the m₁-vein and sometimes also on the m-stem. The tibial organ consists of bright setae in contrast to most other species of the genus, in which they are usually dark. For differences to the sister species Trichosiopsis clavicaudata see under the latter.

DNA Barcoding

The COI sequence is assigned to BIN BOLD:ACX3400 (average distance 0.43%, max. 0.8%, n=4, K2P: 7.262%).

Discussion

By the rounded gonostylus this species belongs to the viatica-complex of species and here to the subgroup of species with reduced macrotrichia on the wing veins.

Etymology

lat. clava = club, forceps = pincers; making reference to the club-shaped gonostylus.

Ecology

Trichosiopsis claviforceps is a strictly boreal species, which occurs northern to 65° N.

Distribution

Finland^[1], Norway, Russia^[2], Sweden^[3][4].

Images

Figure 1. Trichosiopsis claviforceps male, habitus, scale 1 mm  Figure 2. Trichosiopsis claviforceps male, hypopygium, scale 0.1 mm  Figure 3. Trichosiopsis claviforceps male, gonostylus (ventral view), scale 0.1 mm  Figure 4. Trichosiopsis claviforceps male, 4th antennal flagellar segment, scale 0.1 mm  Figure 5. Trichosiopsis claviforceps male, palpus, scale 0.1 mm  Figure 6. Trichosiopsis claviforceps male, wing, scale 1 mm

References

1. ↑ ^{1.0 1.1} Tuomikoski, R. 1960: Zur Kenntnis der Sciariden (Dipt.) Finnlands. Annales Zoologici Societatis Zoologicae Botanicae Fennicae “Vanamo”, 21, 1–164.
2. ↑ ^{2.0 2.1} Mohrig, W.; Menzel, F. 1997: Revision der paläarktischen Arten von Trichosia Winnertz sensu Tuomikoski, 1960 (Diptera, Sciaridae). – Teil II. Gattungen Leptosciarella Tuomikoski, 1960 und Trichodapus gen. nov. Studia dipterologica, 4(1), 41–98.
3. ↑ Rudzinski, H.-G. 1992: Neue Mitteilungen zum Vorkommen von Trauermücken in Schweden (Diptera: Nematocera: Sciaridae). Entomologische Zeitschrift, 102, 66–72.
4. ↑ Heller, K.; Vilkamaa, P.; Hippa, H. 2009: An annotated check list of Swedish black fungus gnats (Diptera, Sciaridae). Sahlbergia, 15(1), 23-51.