B ryophaenocladius adigensis sp . n ., a new species from the i talian a lps (c hironomidae , o rthocladiinae )

Bryophaenocladius adigensis sp. n., is diagnosed and described based on two male adults material collected in the Sardagna stream, near the city of Trento (Northern Italy). Although the male of B. adigensis sp. n. shows some morphological affinities with other Bryophaenocladius species ( B. aestivus , B. flexidens , B. muscicola , B. subvernalis and B. thaleri ), it exhibits a combination of unique characters that make it a different species: pal-pomere 3 with 3 typical sensilla coeloconica; absence of antepronotal setae; antennal ratio= 0.86; tergite IX and anal point without lateral expansion; aedeagal lobe typically sub-oval; virga consisting of 2 curved unequal spines; distal part of gonocox-ite with a vertical row of setae; inferior volsella, long nose-like shaped, distal part spatulate with 2 characteristic pre-apical setae, median part bare. Currently,


Introduction
An extensive material collected with a sweep net in the Sardagna stream, a tributary of the River Adige the city of Trento (Northern Italy), revealed the presence of a new species of the genus Bryophaenocladius, Bryophaenoladius adigensis sp.n.The genus Bryophaenocladius was stated by Thienemann in 1934 with Orthocladius muscicola Kieffer, 1906 as type species.To date, more than 100 species have been recorded all over the world of which 42 in Europe and 11 in Italy (Rossaro et al. 2019), now 12.

Material and methods
Material is composed of 2 male adults collected in the Sardagna stream (Northern Italy), using a sweep net, and then preserved in 80-85% ethanol.The methodology of mounting and conservation of the holotype and paratype material is provided in Moubayed andLangton (2019, 2023).Morphological terminology and measurements follow those of Saether (1980) and Langton and Pinder (2007).
Paratype: 1 male adult, same locality and data as for holotype, deposited in the collection of the first author.

Etymology
The species 'adigensis' is named after the second longest river in Italy, the Adige River, which crosses the Trentino-Alto Adige and Veneto Regions in northern Italy and of which the Sardagna stream is a tributary.

Description Male adult
(n = 2; Figs 1A-L) Medium sized species.Total length (TL) 2.45 mm.Wing length (WL) 1.70 mm.TL/WL = 1.44.General colouration contrasting pale brown to dark brown-blackish.Head dark brown to blackish, antenna pale brownish; thorax contrasting brown to dark brown with blackish mesonotal stripes, scutellum brownish with blackish margins; legs uniformly brownish; abdomen brownish, anal segment contrasting from pale brown to dark brown.
Abdomen.Hypopygium in dorsal and ventral view as in Figs 1F-G K) about 75 µm long and 25 µm maximum width, without posterior projection; anterior side covered with short and long fine setae; posterior margin distinctly rounded; crista dorsalis (Fig. 1J) low lobe-like, clearly visible in lateral view; megaseta well-developed.HV = 3.27; HR = 2.40.

Faunal data and taxonomic remarks
Based on recently published faunal data on known  Willassen, 1996, a combination of some morphological distinctive characters found in the male adult are highlighted in the following differentiating characters, which will separate the new species from other related congeners: coronal triangle (Fig. 1A) heartshaped; clypeus (Fig. 1B) smoothly square-like; palpomere 3 (Fig. 1C) with 3 typical sensilla coeloconica; antepronotals (Fig. 1D) absent; tergite confluence with the Adige River in Trento (Fig. 2).Sardagna is a mountain stream, fed mainly by groundwater, its source is located in the Sardagna village, from which it waterfalls down to Trento.The stream is characterised by hard and basic water, with a conductivity of 320-415 µS/cm and a pH of 8.0-8.6, and chilly waters, with a temperature ranging from 7 to 12-14°C from spring to autumn.Enriched substratum with submerged and emergent bryophytes, humus, deciduous wood and tree bark present the riparian zone of the stream are believed to represent the most favourable microhabitats for the larvae, as typical for larvae of this genus known to be semi-terrestrial in groundwater-fed streams (Lindegaard 1995, Lencioni et al. 2011).
Geographical distribution of B. adigensis sp.n. is currently restricted to its type-locality.