Dictyogenus jurassicum Reding, Launay, Le Doaré, Ruffoni & Vinçon, 2019

Reding, Jean-Paul G., Launay, Bertrand, Doaré, Jacques Le, Ruffoni, Alexandre & Vinçon, Gilles, 2019, Two New Species Of Dictyogenus Klapálek, 1904 (Plecoptera: Perlodidae) From The Jura Mountains Of France And Switzerland, And From The French Vercors And Chartreuse Massifs, Illiesia 15 (2), pp. 27-64 : 31-40

Dictyogenus jurassicum Reding, Launay, Le Doaré, Ruffoni & Vinçon , sp. n.

http://lsid.speciesfile.org/urn:lsid: Plecoptera .speciesfile.org:

TaxonName:506375 ( Figs. 1–25 )

Dictyogenus (Besdolus) ventralis – Verneaux, J. (1973). Annales scientifiques de l’Université de Besançon, Zoologie, Physiologie et Biologie Animale, 3ème Série, 9:98.

Dictyogenus fontium – Reding, J.-P.G. (1998). Bulletin romand d’entomologie, 16:42.

Dictyogenus alpinum – Verneaux et al. (2003). Hydrobiologia, 490:71.

Dictyogenus fontium gr sp 5-GV sensu Gilles Vinçon (early-release DNA sequence on: www.boldsystems.org, unpublished)

Materials examined. Holotype male: SWITZERLAND, Jura Mountains , Doubs Valley , canton of Jura , Karstic spring of Côte au Bouvier , near Soubey, 47° 18.028074'N, 7° 3.595063'E, 570m a.s.l., 05.05.2009, leg. Gilles Vinçon, deposited in the MZL (catalogue number: GBIFCH00652518 ). Paratypes: same locality, 16.06.2009, 2♂, 2♀, leg. G. Vinçon, deposited in the MZL (catalogue number: GBIFCH00652530 , GBIFCH00652524 ). Jura Mountains , canton of Jura , Karstic spring near river Sorne, Blanches-Fontaines , 47° 17.338724'N, 7° 13.36608'E, 585m a.s.l., 06.04.2017, 1L, leg. J.-P.G. Reding, deposited in the MZL (catalogue number GBIFCH00652527 ).

Additional specimens. We examined many other specimens. These are stored in the collections of Jean-Paul G. Reding (RC), Bertrand Launay (BLC), Natural History Museum of Hungary (NHMH), Gilles Vinçon (GVC), Jacques Le Doaré ( JLDC), Alexandre Ruffoni ( ARC) and MZL.

SWITZERLAND

Jura Mountains

Chasseron region, Areuse river basin, canton of Vaud, Rhine tributaries:

 Small spring at Dénériaz coomb, 46° 51.180076'N, 6° 31.639395'E, 1135m, 20.09.1993, 3L; 31.07.1996, 1L ; 13.10.1996, 1L ; 30.08.2000, 1L ; 10.05.2002, 1L ; 18.07.2006, 4L ; 29.06.2010, 1L (used for molecular studies by A. Reding), 1E; 04.05.2011, 1L (used for molecular studies by A. Reding); 18.05.2011, 1L ; 04.07.2011, 1L ; 13.12.2013, 1L ; 27.08.2014, 1L (leg. J.-P.G. Reding; RC).

 Dénériaz torrent, Noirvaux, 46° 51.228685'N, 6° 30.969797'E, 1000 m, 31.03.2005, 6L (leg. J.-P.G. Reding; RC); 13.08.2017, 1L, (leg. J. Le Doaré; JLDC).

 Small spring, Poëta Raisse gorges, 46° 52.910488'N, 6° 36.307303'E, 1131m, 18.07.1997, 1E; 03.08.2011, 2L; 23.06.2012, 2L (leg. J.-P.G. Reding; RC). Orbe River Basin, canton of Vaud, Rhine tributaries:

 Karstic spring Les Fontannets, La Mothe, 46° 49.165452'N, 6° 33.889242'E, 548m, 09.05.2014, 1L (leg. J.-P.G. Reding; MZL under catalogue number GBIFCH00284213, used for molecular studies by SwissBOL). Doubs Valley, canton of Jura, Rhône tributaries:

 Karstic spring of Côte au Bouvier, near Soubey, 47° 18.028074'N, 7° 3.595063'E, 570m, 26.05.1997, 1♂, 2♀, 1E; 05.05.2009, 3♂; 16.06.2009, 2♂, 10♀, 2E; 20.06.2012, 4♀, 4E (leg. G. Vinçon; GVC); 12.06.2007, 3♂, 1E; 24.06.2007, 1♂, 1E (leg. R. Rupprecht; GVC); 29.05.2010, 5L (used for molecular studies by A. Reding); 14.07.2010, 1L (leg. A. Reding; RC); 20.09.2010, 11L; 23.09.2014, 2L (leg. J.-P.G. Reding; RC). Canton of Jura, Rhine tributaries:

 Karstic spring near river Sorne, Blanches- Fontaines, 47° 17.338724'N, 7° 13.36608'E, 585m, 10.03.2015, 1L (leg. J.-P.G. Reding; MZL under catalogue number GBIFCH00284212, used for molecular studies by SwissBOL); 06.04.2017, 1L (leg. J.-P.G. Reding; RC). FRANCE Jura Mountains Doubs Department (25) Doubs drainage basin, Rhône tributaries:  Spring of Doubs River, Mouthe, 46° 42.295779'N, 6° 12.548421'E, 946m, 18.04.1991, 2L; 15.09.1991, 1E (leg. J. Aubert; GVC); 14.07.1996, 1♀, 7E (leg. G. Vinçon; GVC); 13.06.2007, 1L (used for molecular studies by A. Reding); 10.05.2017, 1L (leg. J.-P.G. Reding; RC). Loue drainage basin, Rhône tributaries:

 Spring of Loue River, Ouhans, 47° 0.645115'N, 6° 17.97486'E, 529m, 10.04.2013, 1L (leg. J.-P.G. Reding; RC).

 Spring of Moulin Miguet, Nouailles Gorges, Ouhans, 47° 1.326046'N, 6° 17.934465'E, 456m, 14.05.2013, 1L; 01.04.2014, 5L; 14.04.2015, 2L (leg. J.-P.G. Reding; RC). Ain (01) and Jura (39) Departments, Ain drainage basin, Rhône tributaries:

 Karstic spring near Albarine river, Charabotte Mill (01), 45° 57.308924'N, 5° 33.286347'E, 476m, 09.06.2013, 2♂, 3♀ (leg B. Launay; JLDC); 15.06.2013, 3♀; 16.02.2014, 2L; 06.05.2014, 1♂, 3♀, 1E (leg. B. Launay; RC); 13.05. 2015, 4m, 1L, 2E (leg. B. Launay; BLC; used for molecular studies by IRSTEA, numbers B116 and B117).

 Valouse river near Cornod (39), bridge over road D 202, 46° 18.536086'N, 5° 32.227764'E, 310m, 12.09.2007, 1L (leg. J. Le Doaré; JLDC).

 Spring of Flumen river, near Les Moulins, Septmoncel (39), 46° 21.204252'N, 5° 54.395038'E, 800m, 24.07.2007, 9L; 28.04.2011, 1L (leg. J. Le Doaré; JLDC).

 Spring of Ravin de la Gaillarde, Tenay (01), 45° 56,078220'N, 5° 32,239020'E, 651m, 13.04.2018, 1L (leg. B. Launay; BLC). Ain Department (01), Valserine drainage basin, Rhône tributaries:

 Karstic spring at Creux-Godet, 46° 16.114284'N, 5° 54.894414'E, 879m, 13.04.1991, 1L (leg. J. Aubert; GVC); 17.03.2014, 2L; 30.05.2014, 1E (leg. B. Launay; BLC); 25.08.2014, 8L (leg. J. Le Doaré; JLDC).

 Brion waterfall, near Chézery-Forens, 46° 15.311212'N, 5° 54.032052'E, 810m, 03.02.2014, 3L; 14.02.2014, 3L; 17.03.2014, 24L (leg. B. Launay; BLC; 2L in RC); 04.05.2014, 3L; 30.05.2014, 2♂, 2E; 19.07.2014, 1♀, 1E; 22.12.2014, 2L; 11.04.2015, 1L; 22.05.2015, 2L; 13.06.2015, 2♂, 1♀, 1E; 08.06.2016, 1♀ (leg. B. Launay; BLC); 27.01.2015, 3L (leg. J.-P.G. Reding; RC).

 Karstic spring near Perissode farm, 46° 22.128147'N, 6° 0.361369'E, 1030m, 05.05.2014, 1L; 20.07.2014, 2♀; 25.08.2014, 11L (leg. J. Le Doaré; JLDC); 26.04.2015, 1L; 01.08.2015, 4L 1E (leg. B. Launay; BLC).

 Forens river tributary, Chézery-Forens, 46° 13.389054'N, 5° 51.127375'E, 700m, 03.02.2014, 1L; 14.02.2014, 2L; 30.05.2014, 1♂, 1♀, 1E; 13.06.2015, 1E (leg. B. Launay; BLC).

 Septfontaine river at Mijoux, 46° 19.277761'N, 5° 57.467904'E, 950m, 03.07.2015, 1L; 01.08.2015, 1♂, 1♀; 05.09.2015, 3L; 02.04.2016, 1L (leg. B. Launay; BLC).

Diagnosis. General color dark brown with tawny and yellow spots ( Figs. 1 , 2 ). Males and females macropterous ( Figs. 1 , 8 ). Apex of the frontal sclerite of the epiproct of adult males slightly bent downwards, in lateral view ( Figs. 5 , 6 ). Female subgenital plate covering half of the ninth sternum and exhibiting a deep median arch-shaped notch ( Fig. 9 ). Body length of males 14–18 mm; females 15–23 mm. Anterior wings of males 15.9–17.6 mm; females 10–20.7 mm. Posterior

wings of males 13.2–15.5 mm; females 13.9–20.5 mm.

Adults ( Figs. 1–9 ). Head mostly brown, with two large lateral yellow circular spots on both sides of the clypeus and a wide, symmetric, yellow patch on the M-line, above the anterior ocellus ( Fig. 2 ). Between the lateral ocelli, a large, tawny area delimitated posteriorly by the epicranial suture. Area between the lateral ocelli and the compound eyes pale yellow ( Fig. 2 ). Pronotum dark brown ( Fig. 2 ). Anterior and posterior angles of pronotum almost rectangular ( Fig. 2 ). Presence of a yellow median band extending from the anterior margin of the pronotum to its posterior margin, widened in its middle section and gradually narrowing toward the posterior margin of pronotum ( Fig. 2 ). A tawny area on each side of the pronotum, with dark, sculpted rugosities ( Fig. 2 ). Abdominal sterna pale brown, with symmetrical, hyphen-like patches. Proximal part of tibiae with a dark band. Antennae and cerci blackish to dark brown ( Figs. 1 , 4 ). Wing venation as typical for the genus ( Ris 1896: 308, Fig. 3 ). Forewing ( Fig. 8 ) and hindwing (cf. Fig. 31 ) with the two cross-veins “ra- rp” and “rp- ma” nearly aligned. Numerous cross- veins forming a reticulated area between RA and RP ( Fig. 8 ). Cross-vein “ra- rp” and subcostal area of forewing faintly infuscate ( Fig. 8 ).

Male terminalia ( Figs. 3–6 ). Presence of distinctly separated hemiterga ( Figs. 3 , 4 ) and an epiproct with a frontal apical sclerite ending in a single long spine and with two shorter dorso-lateral spines ( Figs. 5 , 6 ). Epiproct flanked by flat and spatulate lateral stylets ( Figs. 5 , 6 ). Tergum 10 divided into hemiterga whose lobes are covered with 20 to 25 pale long setae in which 2 to 9 darker, stronger and longer spines (half of the length of the hemitergal lobes) are embedded ( Fig. 3 ). Hemitergal lobes long and slender, bent obliquely upwards ( Fig. 3 ) and rearwards ( Fig. 4 ). Apex of frontal sclerite of epiproct slightly bent downwards, in lateral view ( Figs. 5 and 6 ). Lateral stylets large and clubshaped, widening near apex, in lateral view ( Figs. 5 and 6 ). Abdominal sternum 7 composed of multiple plates ( Fig. 7 ).

Females ( Fig. 9 ). Females of Dictyogenus not formally identifiable to species level, except those of D. alpinum , whose subgenital plate covers the majority of the sternum 9 ( Figs. 60, 61 ). Female subgenital plate of D. jurassicum sp. n. covering half of the ninth sternum and exhibiting a deep median arch-shaped notch ( Fig. 9 ).

Mature larvae ( Figs. 10–19 ). Larvae <8 mm not identifiable to species-level. Immature larvae are characterized by a very dense setation on abdominal segments, legs, paragenital plates as well as cerci and live in interstitial habitats composed of loose sandy gravels. Mature larvae, on the contrary, are petricolous and this habitat shift also coincides with important chaetotactic changes, notably the reduction of length and number of setae on abdominal segments, paragenital plates and cerci.

Length of mature larvae, measured from head to end of abdomen: 9–19 mm. First two abdominal segments with abdominal terga and sterna clearly separated by a small membranous area ( Fig. 19 ). Interocellar area with a narrow yellow patch not reaching lateral ocelli ( Figs. 10 , 11 ). Lateral ocelli without circum-ocellar yellow patch ( Figs. 10 , 11 ). A narrow elongated yellow patch above each lateral ocellus ( Figs. 10 , 11 ). M-line indistinct ( Figs. 10 , 11 ). Occipital fold and lower rim of the eyes with a conspicuous row of spines ( Fig. 11 ; cf. also Fig. 66 ). Lacinia with apical and subapical tooth; marginal setae of the lacinia in a single long row ( Fig. 12 ). Lacinia, below subapical tooth, with a shoulder-like angle ( Fig. 12 ; cf. also Fig. 64 ). Shape of pronotum ovoid ( Fig. 11 ). Medio-dorsal setae on pronotum short and scattered, arranged as several, loosely demarcated rows ( Fig. 13 ). Medio-dorsal row of setae long and continuous on mesonotum and metanotum ( Fig. 14 ). Medio-dorsal row of setae on abdominal terga short and sparse ( Fig. 15 ). Posterior margins of median abdominal terga with setae of unequal lengths ( Fig. 18 ). Tip of paragenital plates blunt, in ventral view ( Fig. 17 ). Paragenital plates, in ventral view, with at most two unpaired spines at or near apex; generally, there is only 1 spine on one of the paragenital plates while the other is devoid of spines ( Fig. 17 ). Numerous empty spine insertion points on the paragenital plates, in ventral view ( Fig. 17 ). Mediodorsal row of swimming-hairs of caudal setae sparse, with interruptions, and as long as or not much longer than the diameter of the cerci ( Fig. 16 ). General aspect as in Fig. 10 .

Egg characteristics ( Figs. 20–25 ). General shape oblong, cross-section trilateral, smoothed ( Figs. 20–22 ). Posterior pole of egg regularly rounded; ridges only slightly protruding ( Figs. 20–22 ). Chorionic surface with granulose follicle cell impressions ( Fig. 23 ). Collar short, flared apically with few ridges of different length (fig. 24). Anchor flat ( Fig. 25 ). Micropyles protruding and arranged singularly near posterior ⅓ of egg ( Fig. 23 ). Eclosion line absent.

Comparison to Congeners.

Adults. In the adult male of Dictyogenus jurassicum sp. n., the hemitergal lobes are strongly bent upwards ( Fig. 3 ) and rearwards ( Fig. 4 ), whereas the hemitergal lobes of D. alpinum are only slightly bent upwards, pointing almost horizontally toward each other ( Fig. 56 ). In the adult males of Dictyogenus jurassicum sp. n. (and also those of D. muranyii sp. n. and the specimens belonging to the D. fontium species complex), there is a wide, Vshaped membranous area between the hemitergal lobe and the inner anterior corner of the hemiterga ( Figs. 3 , 29 , 32 , 81 ). In the adult males of Dictyogenus alpinum , on the contrary, the area between the hemitergal lobe and the inner anterior corner of the hemiterga is globulous and sclerotized ( Fig. 56 ). In Dictyogenus jurassicum sp. n., the lateral stylets are enlarged apically ( Fig. 5 ), whereas they are getting progressively thinner toward the apex in D. alpinum ( Fig. 57 ). In the female of Dictyogenus jurassicum sp. n., the subgenital plate ( Fig. 9 ) covers at most the upper half of abdominal sternum 9, as is also the case for specimens of the D. fontium species complex ( Figs. 83 , 84 ), whereas the subgenital plate of D. alpinum covers ¾ of the sternum 9 ( Figs. 60, 61 ). Adult females of Dictyogenus jurassicum sp. n. hence have more affinities with those of the D. fontium species complex than with those of D. alpinum , whereas adult males of Dictyogenus jurassicum sp. n. are closer to those of D. alpinum than to those of the D. fontium species complex, from which they differ by the much stronger curvature of the apex of the frontal epiproct sclerite in lateral view ( Figs. 5 , 6 , 57 compared to Fig. 80 ).

Mature larvae. Dictyogenus jurassicum sp. n. differs from D. fontium by the presence of medio-dorsal setae on the pronotum ( Fig. 13 compared to Fig. 86 ). Medio-dorsal setae on pronotum of Dictyogenus jurassicum sp. n. are short and scattered, arranged as two loosely demarcated rows ( Fig. 13 ), whereas they are longer, but uncompacted, in D. muranyii sp. n. ( Figs. 40, 41 ), and dense and long in D. alpinum ( Fig. 71 ).

Distribution and ecology. Dictyogenus jurassicum sp. n. is the only species of Dictyogenus present in the Jura Mountains of France and Switzerland ( Fig. 92 ) and is distributed over all its different drainage basins. The occurrence of Dictyogenus jurassicum sp. n. is, however, restricted to karstic springs (some of them intermittent) and the initial section of their outflows in the Jura Mountains of France and Switzerland ( Fig. 26 ). The flight period of D. jurassicum sp. n. extends from spring to early summer. Adults of both sexes emerge from the middle of April until the beginning of July. The life cycle is unknown. Our observations in the field are compatible with a semivoltine cycle, since immature larvae (3-4 mm) were generally found together with pre-emergent larvae in spring, at the end of the emergence period of adults. Half-grown larvae (6-8 mm) are present in autumn and in winter. Thus, larval growth of Dictyogenus jurassicum sp. n. extends over a period of at least two years. A possible egg diapause, as documented for a population of Dictyogenus fontium by Zwick & Zwick 2010, would extend its life cycle to three years.

Etymology of Dictyogenus jurassicum sp. n. The new species is named after the region where it was collected, the Jura Mountains of France and Switzerland.

Figures

Fig. 1. Dictyogenus jurassicum sp. n., adult female habitus. Spring of River Doubs, Mouthe, Doubs dpt, France. Photo A. Ruffoni.

Figs. 2-3. Dictyogenus jurassicum sp. n. 2. Adult female, head and pronotum. Spring of River Doubs, Mouthe, Doubs dpt, France. Photo A. Ruffoni. 3. Adult male, hemitergites, dorsal view. Karstic spring at Charabotte Mill, Ain dpt, France. Photo B. Launay.

Figs. 4-5. Dictyogenus jurassicum sp. n., adult male. 4. Hemitergal lobe, lateral view. Karstic spring at Charabotte Mill, Ain dpt, France. Photo B. Launay. 5. Epiproct and lateral stylet, lateral view. Karstic spring at Charabotte Mill, Ain dpt, France. Photo B. Launay.

Figs. 6-7. Dictyogenus jurassicum sp. n., adult male. 6. Epiproct and lateral stylet, lateral view. Karstic spring at Charabotte Mill, Ain dpt, France. Photo B. Launay. 7. Posterior margin of sternite 7 with ventral vesicle, ventral view. Karstic spring at Charabotte Mill, Ain dpt, France. Photo J.-P.G. Reding.

Fig. 8. Dictyogenus jurassicum sp. n., adult male, venation of forewing (annotations by Dr. Olivier Béthoux). Karstic spring at Charabotte Mill, Ain dpt, France. Photo B. Launay.

Fig. 9. Dictyogenus jurassicum sp. n., female, subgenital plate, ventral view. Spring of River Doubs, Mouthe, Doubs dpt, France. Photo A. Ruffoni.

Fig. 10. Dictyogenus jurassicum sp. n., larva. Spring of River Doubs, Mouthe, Doubs dpt, France. Photo A. Ruffoni.

Figs. 11-19. Dictyogenus jurassicum sp. n., larva. Karstic spring of Côte au Bouvier, near Soubey, canton of Jura, Switzerland. All images credited to J.-P.G. Reding. 11. Head and pronotum, dorsal view. 12. Lacinia. 13. Pronotum, dorso-lateral view. 14. Mesonotum and metanotum, dorso-lateral view. 15. Abdominal tergites, lateral view. 16. Medio-dorsal row of setae on base of cerci, lateral view. 17. Paragenital lobes, ventral view. 18. Tergites 5, 6 and 7, dorsal view. 19. Separation of tergites and sternites, lateral view.

Figs. 20-25. Dictyogenus jurassicum sp. n., egg characteristics. 20. Egg, lateral view. Karstic spring of Côte au Bouvier, near Soubey, canton of Jura, Switzerland. 21. Egg, lateral view. Karstic spring of Côte au Bouvier, near Soubey, canton of Jura, Switzerland. 22. Egg, lateral view, with ridge and micropyles visible. Karstic spring of Côte au Bouvier, near Soubey, canton of Jura, Switzerland. 23. Detail of egg chorion and micropyles. Karstic spring of Côte au Bouvier, near Soubey, canton of Jura, Switzerland. 24. Egg, collar. Karstic spring of Côte au Bouvier, near Soubey, canton of Jura, Switzerland. 25. Egg, collar and anchor. Karstic spring of Côte au Bouvier, near Soubey, canton of Jura, Switzerland.

Fig. 31. Dictyogenus muranyii sp. n., male, hindwing. Karstic spring of Bruyant, Isère dpt, France. Photo B. Launay.

Figs. 58-61. Dictyogenus alpinum, male and female adults. 58. Adult male, epiproct, dorso-caudal view. Nant Bénin River, Savoie dpt, France. Photo B. Launay. 59. Adult male, posterior margin of sternite 7 with ventral vesicle, ventral view. Nant Bénin River, Savoie dpt, France. Photo B. Launay. 60. Female, subgenital plate, ventral view. Ristolas – Mount Viso, Queyras, Hautes-Alpes dpt, France. Photo J.-P. G. Reding. 61. Adult female, subgenital plate, ventral view. Guiers vif, Chartreuse, Savoie dpt, France. Photo A. Ruffoni. pointing almost horizontally toward each other (Figs. 29, 32). Hemitergal lobes more

Figs. 63-71. Dictyogenus alpinum, larva. 63. Head and pronotum. Rioufroid, Lus-la-Croix-Haute, Drôme dpt, France. Photo A. Ruffoni. 64. Lacinia. Rioufroid, Lus-la-Croix-Haute, Drôme dpt, France. Photo A. Ruffoni. 65. Pronotum, mesonotum and metanotum, lateral view. Vorz river, Belledonne massif, Isère dpt, France. Photo B. Launay. 66. Detail of head. Rioufroid, Lus-la-Croix-Haute, Drôme dpt, France. Photo A. Ruffoni. 67. Medio-dorsal setae on cerci. Riau du Gros Mont, Les Planeys, canton of Fribourg, Switzerland. Photo J.- P.G. Reding. 68. Paragenital plates, ventral view. Riau du Gros Mont, Les Planeys, canton of Fribourg, Switzerland. Photo J.-P.G. Reding. 69. Stipe. Vorz river, Belledonne massif, Isère dpt, France. Photo B. Launay. 70. Femur and tibia of hind leg, lateral view. Riau du Gros Mont, Les Planeys, canton of Fribourg,

Fig. 56. Dictyogenus alpinum, male, hemitergal lobes, dorsal view. Nant Bénin River, Savoie dpt, France. Photo B. Launay.

Figs. 29-30. Dictyogenus muranyii sp. n., male terminalia. 29. Hemitergal lobes, dorsal view. Karstic spring of Bruyant, Isère dpt, France. Photo B. Launay. 30. Hemitergal lobes, lateral view. Karstic spring of Bruyant, Isère dpt, France. Photo B. Launay.

Figs. 32-35. Dictyogenus muranyii sp. n., male terminalia. 32. Hemitergal lobes, dorsal view. Karstic spring of Font Noire, Isère dpt, France. Photo B. Launay. 33. Epiproct, lateral view. Karstic spring of Font Noire, Isère dpt, France. Photo B. Launay. 34. Lateral stylet, lateral view. Karstic spring of Brudour, Drôme dpt, France. Photo B. Launay. 35. Epiproct, dorso-caudal view. Karstic spring of Font Noire, Isère dpt, France. Photo B. Launay.

Figs. 79-82. Dictyogenus fontium species complex, adults. 79. Female, head and pronotum. Inner-alpine upper Isère Valley. Col de l’Iseran, Savoie dpt, France. Photo A. Ruffoni. 80. Adult male, epiproct with frontal apical sclerite and lateral stylet, lateral view. Julian Alps, Slovenia. Photo J.-P.G. Reding. 81. Adult male hemitergal lobes, dorsal view. Rhaetian Alps, Switzerland. Photo J.-P.G. Reding. 82. Adult male, posterior margin of sternite 7 with ventral vesicle, ventral view. Rhaetian Alps, Switzerland. Photo J.-P.G. Reding.

Fig. 57. Dictyogenus alpinum, male, epiproct, lateral view. Nant Bénin River, Savoie dpt, France. Photo B. Launay.

Fig. 83. Dictyogenus fontium species complex, female, subgenital plate. Inner-alpine upper Isère Valley. Col de l’Iseran, Savoie dpt, France. Photo A. Ruffoni.

Fig. 84. Dictyogenus fontium species complex, female, subgenital plate. Rhaetian Alps, Switzerland. Photo J.- P.G. Reding.

Figs. 85-87. Dictyogenus fontium species complex, larva. 85. Pronotum, lateral view. Inner-alpine upper Isère Valley. Col de l’Iseran, Savoie dpt, France. Photo Alexandre Ruffoni. 86. Pronotum, lateral view. Inneralpine upper Swiss Rhône valley, Anniviers Valley, canton of Valais, Switzerland. Photo J.-P.G. Reding. 87. Hind leg, lateral view. Inner-alpine upper Swiss Rhône valley, Anniviers Valley, canton of Valais, Switzerland. Photo J.-P.G. Reding.

Figs. 38-45. Dictyogenus muranyii sp. n., larva. 38. Head, pronotum and mesonotum, dorsal view. Karstic spring of Brudour, Drôme dpt, France. Photo B. Launay. 39. Head, pronotum, dorsal view. Karstic spring of Brudour, Drôme dpt, France. Photo A. Ruffoni. 40. Head, pronotum, mesonotum and metanotum, lateral view. Karstic spring of Bruyant, Isère dpt, France. Photo A. Ruffoni. 41. Pronotum, lateral view. Karstic spring of Bruyant, Isère dpt, France. Photo J.-P.G. Reding. 42. Abdominal segments, lateral view. Karstic

Fig. 92. Distribution map of Dictyogenus species in the Central and Western Alps. Legend: Dictyogenus jurassicum, yellow dots; D. muranyii, black dots; D. alpinum, red dots; D. fontium species complex, blue dots. Distribution data are those of the authors and Opie-Benthos. Map data: SRTM V4 (http://srtm.csi.cgiar.org), generated with ArcGIS version 10.3.0.4322.

Fig. 26. Dictyogenus jurassicum sp. n., biotope. Karstic spring of River Doubs, Mouthe, Doubs dpt, France. Photo: J.-P. G. Reding.