- Trichosia (Leptosciarella) Tuomikoski, 1960: 20 synonym – type species: Sciara elegans Winnertz, 1867 [= Trichosiopsis scutellata (Staeger, 1840)]
Head. Eye bridge 3–5 rows of facets. LW-index of 4th antennal flagellar segment 1.5–4.0; Transition of basal part to neck pronounced. Palpomeres 3., rarely 2. First palpomere with numerous bristles; with only some sparse sensillae. Thorax. Thoracic setae strong or normal. Posterior pronotum normally setose. Laterotergite normally bare, rarely with bristles. Legs. Frontal tibia with a patch of setae. Front tibial organ mostly dark. Front tibial organ not bordered. Tibial spurs elongate, of equal length. Claws untoothed. Wings. Wings darkened, of normal shape. Wing membrane without macrotrichia. Wing venation normal. M-fork of normal shape. R1 inserting at or slightly before base of m-fork; posterior veins mostly with macrotrichia. Halteres of normal length. Abdomen. Abdominal setae normally strong and dense. Hypopygium concolour with abdomen. Inner margin of gonocoxites normally U-shaped; inner part of hypopygium densely setose; elongated setae on valves of hypopygium absent. Gonostylus elongate; inner margin straight, or concave. Apical tooth present. Apical awl-like setae present. Megasetae on inner part of gonostylus absent. Tegmen mostly rectangular with rounded edges; central process absent. Measurements. Body size 2.0–4.5 mm. Wing length 2–4.5 mm.
Trichosiopsis belongs to the basal subfamily Sciarinae together with Sciara and Trichosia. These genera are characterized by setose wing veins and a patch of numerous setae on the inner side of the apex of the fore tibia (tibial organ). Characteristic for the genus are the awl-like setae at the apical part of the gonostylus. Awl-like setae occur otherwise only in the genus Sciara. Trichosiopsis can be distinguished from Sciara by the presence of an apical tooth (Menzel & Mohrig 2000: 355). The species are normally dark, slender, strongly setose and have long legs.
The greek suffix -opsis means “appearance” and refers to the similarity of the genus with Trichosia.
Species of this genus are mainly found in forests. Many species live upon dead wood and the adults occur mostly in spring.
Leptosciarella was originally defined by Tuomikoski as a subgenus of Trichosia. Amorim (1992: 62) was the first, who treated Leptosciarella as a genus, but without any discussion. Due to the lack of autapomorphic characters of Trichosia s.l. (Mohrig & Menzel 1997) confirmed this usage and defined the genus on the presence of a beak-like apical tooth and awl-shaped setae at the tip of the male gonostyli. Although these characters can be variable among species, the genus is quite clear-cut and there are currently few doubts about its delimitations. They distinguished five subgenera (Hirtipennia, Leptosciarella, Leptospina, Trichosiopsis and Protosciarella). In the latest revision of the genus (Mohrig & Menzel 1997) 36 species were included, with Leptosciarella s. str. being by far the largest subgenus with 27 species. 55 species are currently assigned to this genus, but a large number of undescribed or unrevised species are also belonging here.
By including Trichosiopsis as a subgenus in Leptosciarella Mohrig & Menzel (1997) neglected the nomenclatoric priority of Trichosiopsis over Leptosciarella. Both names were published in the same work by Tuomikoski (1960), Trichosiopsis as a genus and Leptosciarella as subgenus of Trichosia. Regarding Art. 24.1. ICZN (1999) the name published at a higher rank takes precedence. Trichosiopsis tuberculigera, the only member of the formerly monotypic subgenus Trichosiopsis defined by its abnormal genitalia is not considered any more as belonging to a separate subgenus and so Trichosiopsis becomes the valid name for Leptosciarella. Furthermore, the subgenera Hirtipennia, Leptospina, and also Neozygoneura (formerly Protosciarella) are to be treated as distinct genera and are excluded here, as already discussed by Rudzinski (2005): 267–268. Also, molecular phylogenetic analysis by Shin et al. (2013) has demonstrated, that at least Leptospina is not monophyletic with Trichosiopsis.
Trichosiopsis alba - Trichosiopsis albescens - Trichosiopsis angustistylus - Trichosiopsis aspiculosa - Trichosiopsis brevior - Trichosiopsis brevipalpa - Trichosiopsis cerifera - Trichosiopsis claviforceps - Trichosiopsis coarctata - Trichosiopsis defecta - Trichosiopsis dimera - Trichosiopsis dives - Trichosiopsis elongatula - Trichosiopsis furiosa - Trichosiopsis fuscipalpa - Trichosiopsis gretae - Trichosiopsis helvetica - Trichosiopsis hirsutissima - Trichosiopsis hispida - Trichosiopsis ignis - Trichosiopsis imberba - Trichosiopsis incomposita - Trichosiopsis ironica - Trichosiopsis juliae - Trichosiopsis juniperi - Trichosiopsis krille - Trichosiopsis longistilis - Trichosiopsis mediterranea - Trichosiopsis melanoma - Trichosiopsis melanoxera - Trichosiopsis nativa - Trichosiopsis neopalpa - Trichosiopsis nudinervosa - Trichosiopsis perturbata - Trichosiopsis pilosa - Trichosiopsis prospera - Trichosiopsis reducta - Trichosiopsis rejecta - Trichosiopsis rotunda - Trichosiopsis saltuum - Trichosiopsis scutellata - Trichosiopsis senex - Trichosiopsis subcoarctata - Trichosiopsis subelegans - Trichosiopsis subpilosa - Trichosiopsis subspinulosa - Trichosiopsis subviatica - Trichosiopsis trochanterata - Trichosiopsis tuberculigera - Trichosiopsis ulagana - Trichosiopsis unicorn - Trichosiopsis viatica - Trichosiopsis viaticella - Trichosiopsis yerburyi - Trichosiopsis zanti
- Tuomikoski, R. 1960: Zur Kenntnis der Sciariden (Dipt.) Finnlands. Annales Zoologici Societatis Zoologicae Botanicae Fennicae “Vanamo”, 21, 1–164.
- Menzel, F.; Mohrig, W. 2000: Revision der paläarktischen Trauermücken (Diptera: Sciaridae). Studia dipterologica Supplement 6, 1-761. AMPYX-Verlag, Halle.
- Amorim, D.S. 1992: A catalogue of the family Sciaridae (Diptera) of the Americas south of the United States. Revista Brasileira de Entomologia, 36, 55–77.
- 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.
- ICZN 1999: International Code of Zoological Nomenclature Fourth Edition, adopted by the International Union of Biological Sciences [Incorporating Declaration 44, amendments of Article 74.7.3, with effect from 31 December 1999 and the Amendment on e-publication, amendments to Articles 8, 9, 10, 21 and 78, with effect from 1 January 2012]. The International Trust for Zoological Nomenclature, London. 
- Rudzinski, H.-G. 2005: Beitrag zur Trauermückenfauna Taiwans Teil II: Gattungen Sciara, Schwenckfeldina, Trichosia, Leptosciarella, Baeosciara und Trichosillana gen. nov. (Diptera Nematocera: Sciaridae). Entomofauna, 26, 253–280. PDF
- Shin, S.; Jung, S.; Menzel, F.; Heller, K. et. al. 2013: Molecular phylogeny of Black Fungus Gnats (Diptera: Sciaroidea: Sciaridae) and the evolution of larval habitats. Molecular Phylogenetics and Evolution, 66(3), 833–846. doi: 10.1016/j.ympev.2012.11.008.
- Mohrig, W. 2003: Black fungus gnats of Central America. Part I. (Diptera, Sciaridae). Beiträge zur Entomologie, 53(1), 1–69.