Dictyogenus vinconi, Reding, 2024

Reding, Jean-Paul G., 2024, Notes on the genus Dictyogenus Klapálek, 1904 (Plecoptera, Perlodidae) in the Austrian, Italian, Slovenian and Swiss Alps, with the description of six new species, Zootaxa 5397 (2), pp. 151-194 : 185-186

2.6 Dictyogenus vinconi sp. n.

urn:lsid:zoobank.org:act:077C87FA-2D1E-42AF-9D94-3D74ABE8E88C

( Figs. I.1–I . 7 )

Adults. Body length of males 22 mm (n = 1); females 23 mm (n = 2). Adult males and females of D. vinconi sp. n. are macropterous ( Figs. I.1 , I.6). Head mostly yellow ( Fig. I.2 ); M-line well marked ( Fig. I.2 ). Interocellar yellow patch wide, continuous with the median yellow band on the pronotum ( Fig. I.2 ). Yellow median band on pronotum widening in its posterior margin ( Fig. I.2 ). Side of the pronotum with sculpted rugosities ( Fig. I.2 ). Abdominal sterna pale brown, with typical dark, arch-like markings ( Fig. I.4 ). Proximal part of tibiae with a dark band. Antennae and cerci blackish to dark brown.

Male terminalia. Tip of epiproct straight, slightly bent down ( Fig. I.3 ). Lateral stylets sickle-shaped, or shaped like a circular segment, with the left side forming a wide arc and the right side with straight edge ( Fig. I.3 ). Apex of lateral stylets narrowing distally ( Fig. I.3 ). Hemitergal lobes long and slender (Fig. I.5).

Morphological affinities. Specimens of D. vinconi sp. n. differ from topotypical D. fontium , D. padanum sp. n. and D. nadigi sp. n. by the lateral stylets of their adult males, which are uniquely characterized by their sickle-shaped aspect ( Fig. I.3 ).

Females. Subgenital plate short, with ( Fig. I.7 ) or without (Fig. I.6) median notch on its distal edge.

Mature nymphs. Unknown.

Type material. ITALY. Reggio Emilia. Passo del Cerreto , La Nuda, 1500 m, 44° 17’ 06.00” N, 10° 13’ 42.96” E, 11.06.2021, 1♁ leg. G. Vinçon (holotype, MZL, GBIFCH01217068 ) ; 10.6.2022, 1♀, 15.6.2020, 1♀, leg. G. Vinçon (paratypes, MZL, GBIFCH01217070 , GBIFCH01217069 ) .

Distribution and ecology. Very rare, stenoendemic species, known only from the region of the vanished La Nuda glacier in the Apennines ( Fig. J.2 ).

Adult flight period. June.

Derivatio nominis. Named in honor of its first collector, Dr. Gilles Vinçon (Grenoble).

Figures

FIGURES A.1–A.3: general characteristics of adult Dictyogenus. A.1—head and pronotum of adult male (D. alpinum); A.2—vesicle on sternite VII of adult male; A.3—venation of forewing of Dictyogenus (annotations by Dr. Olivier Béthoux). Photo Bertrand Launay.

FIGURES B.7–B.12: nymphs of Dictyogenus alpinum. B.7—mediodorsal setation of nymph (head and pronotum); B.8— spines on paraprocts of nymph, in ventral view; B.9—mediodorsal setae on cerci; B.10—spines on stipe of nymph; B.11— mature female nymph, sternite 8, ventral view; B.12—mediodorsal setation on tergites of nymph.

FIGURES I.2–I.7: Dictyogenus vinconi sp. n. I.2—adult female, head and pronotum; I.3—epiproct and lateral stylet of adult male; I.4—ventral lobe on sternite VII of adult male; I.5—hemitergal lobes of adult male; I.6—subgenital plate of adult female; I.7—subgenital plate of adult female.

FIGURES A.4–A.9: general characteristics nymphal Dictyogenus. A.4—separation of abdominal tergites I and II; A.5— lacinia with shoulder-like angle; A.6—prefigured ventral vesicle on sternite VII in mature male nymph, ventral view; A.7— nymph, row of stiff spines on occiput (dorsal view); A.8—female nymph, sternite VIII, ventral view; A.9—female nymph, sternite VIII, ventral view.

FIGURES J.3: distribution maps of Dictyogenus. J.3—distribution map of Dictyogenus (topotypical D. fontium, D. nadigi sp. n., and D. padanum sp. n.) in alpine drainage basins.