Larval Taxonomy and Distribution of Genus Hydropsyche (Trichoptera: Hydropsychidae) in Northwestern Algeria Author Bemmoussat-Dekkak, Soumya 0000-0002-8723-5501 Laboratoire de Valorisation des Actions de l’Homme pour la Protection de l’Environnement et Applications en Santé publique, Université de Tlemcen, BP 119 13000 Tlemcen, Algérie. & dekkaksoumia @ hotmail. fr; https: // orcid. org / 0000 - 0002 - 8723 - 5501 dekkaksoumia@hotmail.fr Author Abdellaoui-Hassaine, Karima 0000-0002-7568-8132 Laboratoire de Valorisation des Actions de l’Homme pour la Protection de l’Environnement et Applications en Santé publique, Université de Tlemcen, BP 119 13000 Tlemcen, Algérie. & hassaine 69 @ hotmail. com; https: // orcid. org / 0000 - 0002 - 7568 - 8132 hassaine69@hotmail.com Author Sartori, Michel 0000-0003-3397-3397 Musée cantonal de zoologie, Palais de Rumine, Place Riponne 6, 1005 Lausanne, Suisse & Département d’Ecologie et d’Evolution, Université de Lausanne, Biophore, 1015 Lausanne, Suisse & michel. sartori @ vd. ch; https: // orcid. org / 0000 - 0003 - 3397 - 3397 michel.sartori@vd.ch Author Morse, John C. 0000-0003-3187-4045 Department of Plant & Environmental Sciences, Clemson University, Clemson, South Carolina, USA & jmorse @ clemson. edu; https: // orcid. org / 0000 - 0003 - 3187 - 4045 jmorse@clemson.edu Author Zamora-Muñoz, Carmen Departamento de Zoología, Facultad de Ciencias, Universidad de Granada, 18071 - Granada (Spain) text Zootaxa 2021 2021-01-25 4915 4 481 505 journal article 8676 10.11646/zootaxa.4915.4.2 70890c1c-cbf0-4135-9bf3-5e22b64e3cd3 1175-5326 4461519 84122919-0AE3-43BB-AECB-6F3CA0D63629 Hydropsyche siltalai Döhler 1963 ( Figs 2 , 3 ) Material examined: Chouly Wadi at Beni Ghazli ( CH 0): 5 mature mƋ pupae ( UTA ) and 4 mƋ adults ( UTA ), 1 Ƌ pupa ( UGS ), 1.v.2015 ; 1 Ƌ pupa ( UTA ), 14.v.2016 ; 2 Ƌ pupae ( UTA ), 17.v.2017 ; 1 Ƌ pupa ( UTA ), 08.v.2017 and 4 Ƌ reared adults ( UTA ), 08.v.2017 ; Chouly Wadi Yebder ( CH 1): 2 mature mƋ pupae ( UTA ) , 1 Ƌ imago ( UTA ), 14.v.2016 ; 1 Ƌ imago ( UTA ), 13.v.2019 ; Safsaf Wadi downstream of the El Ourit Area (SK1): 5 mƋ ( UTA ) ; 2 mƋ adults ( UTA , UGS ), 25.vii.2016 ; 3 mƋ adults ( UTA ), 21.x.2019 ; Chouly Wadi in Beni Ghazli ( CH 0): 55 H. siltalai morphotype 1 larvae ( UTA ) ; Chouly Wadi in Yebdar ( CH 1): 192 H. siltalai morphotype 2 larvae ( UTA ) ; Safsaf Wadi (SK1): 154 morphotype 2 ( UTA , UGS ) ; Khemis Wadi (KH1): 62 morphotype 2 ( UTA , UGS ) . Description: Body length of fifth-instar larva ranging from 12.5 to 14.0 mm. Morphotype 1 with head and pronotum very light brown ( Figs 2A, 2B ); morphotype 2 darker ( Figs 3A, 3B ). Specimens collected in Algeria morphologically identical to their French or Spanish conspecifics, except for small difference in shape of median spot on frontoclypeus, slightly wider in morphotype 1 and longer and bifurcate in morphotype 2. Oral and aboral light spots of apotome joined in morphotype 1 ( Fig. 2B ) and not joined in morphotype 2 ( Fig. 3B ). In both morphotypes, lateral parts of submentum short and wide ( Figs 2C , 3C ) and prosternites pigmented ( Figs 2D , 3D ). Distribution and ecology: The distribution area of H. siltalai covers Western Europe (West Palearctic species). Hildrew & Edington (1979) have described it as a species of “small streams”. In Europe, H. siltalai appears to be a submontane species that is also present in low mountain streams with altitudes varying between 200–800 m a.s.l and sometimes even below 200 m a.s.l. It is a eurythermal and rheophilic species living in the metarhithral and hyporhithral zones, occurring in microhabitats composed of coarse gravel, stones, boulders, bedrock, woody fragments, macrophytes, mosses, and green algae ( Graf et al. 2008 ). This species was collected at only four sites of the Tafna Wadi tributaries. The larvae of the fifth instar were usually collected during March, April, and May at Chouly (1065- 916 m a.s.l.) and Khemis Wadis ( 723 m a.s.l). However, at Safsaf Wadi, the species was found only in August and September. These sites ( CH 0, CH 1, and SK1) are located at altitudes between 723 and 1065 m a.s.l. where the stream beds do not exceed 4 m width. At the Safsaf Wadi site (SK1), it was even found in a stream bed with small heterometric rocks. Its largest populations have been observed at higher altitudes at Chouly Wadi sites ( CH 0, CH 1). It seems to be a stenothermal rheophilic species inhabiting heterometric blocks and pebbles in clear and poorly mineralized waters with no salinity, very high oxygenation ( 8.41–10.06 mg /l), and with a low to high level of nitrates ( 1.78–4.9 mg /l). The microhabitats of this species are devoid of aquatic vegetation, on the other hand the riparian vegetation is very dense.