Electrogena brulini Wagner,
Wagner, Andre, Vuataz, Laurent & Sartori, Michel, 2017, Electrogena brulini sp. nov. and E. vipavensis Zurwerra & Tomka, 1986 syn. nov. revealed by integrative taxonomy of E. gridellii (Grandi, 1953) (Ephemeroptera: Heptageniidae), Zootaxa 4362 (3), pp. 359-384: 364-366
treatment provided by
|Electrogena brulini Wagner|
Electrogena brulini Wagner , sp. nov.
Electrogena gridellii sensu Belfiore (1996) pro parte, nec Belfiore (1982)
Nymph description: Length: Male: body 7–10 mm, cerci 8–12 mm. Female: body 8–11 mm, cerci 10–15 mm. Colouration of cuticle generally greyish, epidermal pigmentation reddish, well contrasted.
Head: surface with distinctive light and dark markings ( Figs 6, 8, 10, 12View FIGURES 2–21), specific to this species; noteworthy the presence of spots (b), between (a) and (c) ( Fig. 6View FIGURES 2–21); a pattern formed by a triangle (f) and a line (d) delimiting a white marking (e) ( Fig. 10View FIGURES 2–21) disappearing almost entirely in last instar; a light line along the inner margin of compound eyes, a dark colouration behind the ocelli ( Figs 8, 12View FIGURES 2–21). Labrum, rather slender, R_LBR = 4.3–5.4; anterior margin with one row of bristles, stout and short in the middle and elongated outwardly ( Figs 40, 44View FIGURES40–51). Mandible with a prostheca bearing 5–8 bristles (N_PRO), all bristles evenly thick, at the most the basal one a little thinner ( Fig. 42View FIGURES40–51). Addition of right and left N_PRO: 10–15 bristles. Maxillae with a row of 16–23 comb-shaped setae on anterior margin (N_ CBS), the 5th (starting from inner side) bearing 8–13 teeth (N_ TCB), outer margin of galea-lacinia with 4–20 setae (N_ OUT), inner margin and ventral face of the first segment of palpus bearing 5–29 thin setae (N_ PLP). Hypopharynx with laterally expanded superlinguae, densely covered with long thin setae, apex of lobes with long setae (as E. gridellii in Fig. 49View FIGURES40–51), sometimes missing when worn or very difficult to see because obscured by dirt as in Fig. 48View FIGURES40–51. Labium, ventral face, only inner third of the paraglossae with bristles (rarely reaching half of the width) ( Fig. 46View FIGURES40–51), R_ GLA = 2.8–3.7, R_GLB = 2.7–3.2.
Thorax: Pronotum with a well contrasted pattern but no reddish-brown spot (h), the lateral margins regularly rounded with a dark line (g) ( Fig. 16View FIGURES 2–21). Mesonotum with several light brown markings, and a brown semilunar vertical one (arrow in Figs 18, 20View FIGURES 2–21). Coxa bicoloured: proximal half white, distal half dark grey ( Figs 28, 30View FIGURES 22–31). Thoracic sterna: sclerites light, imaginal colouration becoming brown during nymph development. Legs: well contrasted pattern rather similar between fore-, mid and hind legs ( Figs 28View FIGURES 22–31, 33View FIGURES 32–39). Femora dorsal face with four markings (distal ones can be joined) forming a white cross always reaching the anterior and the posterior margins, strong contrast visible at all instars ( Figs 4View FIGURES 2–21, 32, 33View FIGURES 32–39); ventral face of femora with a large spot, generally double, a dark cuticular spot ( Fig. 27View FIGURES 22–31, k) covering a reddish epidermal one ( Fig. 27View FIGURES 22–31, j) already visible in young nymphs ( Fig. 32View FIGURES 32–39); medium sized blunt pointed bristles on the dorsal face of forefemora ( Fig. 36View FIGURES 32–39), more peaked in mid and hind femora ( Fig. 37View FIGURES 32–39); only one (sometimes none) strong spine in the middle of the ventral face of all femora, near the outer margin (N_BVF). Tibia contrasted, distal quarter and proximal third light, middle darker ( Figs 28View FIGURES 22–31, 33View FIGURES 32–39); pectinate setae scarce on foretibia, numerous on mid and hind tibia ( Fig. 35View FIGURES 32–39, inset). Tarsi with proximal and distal part darkened (mainly on dorsal face), exceptionally forming a distinct ring on distal part; claws with 2 teeth, rarely 3 (N_CLW).
Abdomen: Terga with contrasted markings: terga IV –V (sometimes also VI) generally with a large dark triangle on the anterior margin ( Fig. 2View FIGURES 2–21), in dark nymphs, only light spots subsisting; terga posterior margin light, rarely with grey line on terga I –VIII, absent on tergum IX; terga II –VII with anterolaterally a very tiny, light, reddish-brown spot, generally covered by the previous tergum, smaller than the posterolateral one ( Fig. 22View FIGURES 22–31); terga II –IX posterolaterally with a reddish-brown spot, faint in terga VIII-IX ( Fig. 22View FIGURES 22–31); no contrast between terga VII and VIII –X ( Fig. 2View FIGURES 2–21); tergum X dark with a light marking on each side ( Fig. 14View FIGURES 2–21); posterior margin of each tergum with thin and elongated spines with microdenticulations at their bases. Sterna II –VIII with a dark, arch-shaped cuticular pattern, epidermis always entirely light ( Fig. 24View FIGURES 22–31), except some nymphs with only a very faint pattern becoming brown as E. gridellii in Fig. 25View FIGURES 22–31; ganglionic chain brownish, only last ganglion and the thoracic ones larger and darker violet ( Fig. 24View FIGURES 22–31). In the male last instar nymphs, styliger processes and titillator visible through sternum IX, but titillators too poorly formed to be diagnostic. Gill I tongue-shaped, gills II –VI broad and asymmetrical, gill VII elongated, narrow at apex and slightly pointed ( Fig. 50View FIGURES40–51). Paracercus and cerci light, becoming darker only in the last instars, colouration fading apically.
Male imago: Length: body 7.5–9 mm, forewing 8.5–10 mm, cerci 20–25 mm.
Head: Eyes clearly separated, sclerite joining the compound eyes weakly rounded forming a wide V ( Fig. 84View FIGURES68–85).
Thorax: dark brown ( Figs 52, 54View FIGURES52–55). Wings veins yellowish-brown; costa, subcosta and radius anterior brighter yellow; distal half of costal and subcostal fields sometimes milky ( Fig. 64View FIGURES 56–67). Distal part or entire forefemora darkened ( Figs 60–61View FIGURES 56–67); mid and hind femora dorsally with a brown spot at the distal third and a second spot, variably visible at the proximal third ( Fig. 60View FIGURES 56–67); ventral face of mid and hind femora with a brown spot at the distal third ( Fig. 61View FIGURES 56–67).
Abdomen: Terga dorsally all uniform medium brown with a pair of lighter comma-shaped markings ( Fig. 56View FIGURES 56–67); posterolaterally a darker marking and laterally a light area ( Fig. 54View FIGURES52–55), anterolaterally sometimes very slightly brownish ( Fig. 54View FIGURES52–55). Sterna pale with a large subtriangular light orange-brown marking covering more or less the entire face, ganglia violet ( Fig. 58View FIGURES 56–67). Cerci brown, colouration fading to the apex. Penis lobes regularly rounded, can be slightly bent outwards, distance between lobes ranging from zero up to a ninth of a penis lobe width ( Fig. 68View FIGURES68–85), numerous small dorsal spines basolaterally on penis lobes ( Fig. 72View FIGURES68–85). Titillator massive, with generally two teeth, shape variable ( Figs 75–78View FIGURES68–85). Styliger almost straight with lateral humps ( Fig. 66View FIGURES 56–67).
Female imago: Length: body 7.5–10 mm, forewing 10–12 mm, cerci 16–20 mm. Same general colouration as in male, but lighter; no colour difference between abdomen and thorax ( Figs 86, 88View FIGURES 86–99). Wings with same colouration as in male ( Fig. 90View FIGURES 86–99). Rusty colouration behind ocelli (n), area between the pair of ocelli and the compound eyes not darkened (l), sclerite joining the compound eyes with only laterally a distinct thin brown line on the margin ( Fig. 98View FIGURES 86–99, m). Subgenital plate covering about half of sternum VIII surface, subanal plate tapering to apex, in apical view narrow and lateral margins rolled up towards the inside ( Figs 94, 95View FIGURES 86–99).
Male and female subimago: Same colouration as imago, but paler. Wings without pattern, entirely grey.
Egg: Dimensions: 150/110µm; micropyle: 10/6.5µm. Chorion entirely and regularly covered with relatively dense microgranules, KCT’s evenly distributed over the surface, but more concentrated and somewhat larger on one pole (about the third of the egg) ( Fig. 100View FIGURES 100–103). Micropyle bordered with the same microgranules as surface ( Fig. 101View FIGURES 100–103).
Etymology. From Michel Brulin ( France), the initiator and driving force of the inventory of mayflies in France. A man who, despite his vast knowledge, remains humble and amazed by the life of these insects.
Diagnosis. Nymph: general colouration contrasted, all femora with a large spot on the ventral face; two teeth on claws; 1 bristle (can miss) on ventral face of femora, near the outer margin; bristles of femora bluntly pointed; prostheca consisting in 5–7 bristles ( Fig. 42View FIGURES40–51).
The nymph of Electrogena ozrensis (Tanasijevic, 1975) has not yet been described. Nevertheless, samples and rearing were performed in April 2017 close to the type-locality in Tuzla ( Bosnia). On the basis of the original description, it was possible to link the reared imagines with E. ozrensis , and then with the nymphs. This work being not a revision of the genus Electrogena , we add only some elements allowing to separate Electrogena brulini sp. nov. from the other cited species; essentially based on the present work and on the complete work of Belfiore (1997):
- the double large reddish and grey spot on the ventral face of femora has never been mentioned in European Electrogena species. Nevertheless, this character should not be confused with other colourations that are common: E. affinis usually with a single well- marked spot; E. lateralis sometimes with a faint spot; E. quadrilineata and E. ozrensis with a similar double coloured spot, but the cuticular one more extended, reaching nearly the inner and the outer margins; E. ujhelyii only with a variable cuticular colouration, a transverse distal band (can reach the apex), a longitudinal band on the inner margin, up to almost the whole face grey in dark populations.
- the middle sized blunted bristles on the dorsal face of femora discriminates E. brulini from the long, narrow and pointed bristles as in E. gridellii , from the rounded distal bristles as in E. grandiae and E. hyblaea , from the truncate parallel bristles as in E. ozrensis and E. quadrilineata .
- the sterna colouration in E. brulini ( Fig. 24View FIGURES 22–31) is less extensive, lateral spots not reaching the posterior margin as in E. ujhelyii ( Fig. 26View FIGURES 22–31). This precision may be important, since both species are sympatric in Friuli-Venetia.
- the regular and more or less symmetrical form of the expansions of the pronotum discriminates it from Electrogena braaschi (Sowa, 1984) which has a unique form of expansions, extending forwards.
Imago: dorsal face of mid and hind femora with a distinct and an indistinct dark band ( Fig. 60View FIGURES 56–67); ventral face of mid and hind femora with a distinct dark spot ( Fig. 61View FIGURES 56–67); venation of wings pale brownish; terga pale reddish-brown, posterolaterally a brown spot and anterolaterally a very slightly brownish little marking ( Figs 54View FIGURES52–55, 56View FIGURES 56–67, 88View FIGURES 86–99); titillators with 2 apico-lateral teeth ( Figs 75–78View FIGURES68–85).
In nymph stage, E. brulini can currently be discriminated from all other species except E. calabra . As we had no fresh specimens and as the meristic and ratio characters are of no help to discriminate E. brulini from E. calabra in the nymph stage, the adults have to be compared to exclude a possible synonymy. In imagines, the very inconspicuous spots of the terga discriminate E. brulini from E. calabra which has, according to Bauernfeind & Soldan (2012) “Basolaterally a rounded dark reddish spot near the anterior border and a smaller dot near the posterior border of segments II –VIII”. In E. brulini , the comparison of Figs 2View FIGURES 2–21 /52 and 3/53 shows that the cuticular colouration is little conservative, but the comparison of Figs 22View FIGURES 22–31 /54 and 23/55 shows that the epidermal lateral spots are more conservative. As we observed such characteristics in our rearing of different Electrogena species, we can assume that it is true in E. calabra too. In females, the comparison with the original description seems to indicate that the subgenital plate covers about ¾ of sternum VIII surface in E. calabra (only about the half in E. brulini ) and that the subanal plate does not taper to the apex in E. calabra . This imaginal colouration, represented in Belfiore (1995) and the characteristics of the subgenital and subanal plates, exclude a synonymy. Nevertheless, a thorough study is needed to better separate the two species in both adult and nymph stages.
Material examined: HOLOTYPE: 1 male nymph (preserved in ethanol), CH / TI, Meride, Gaggiolo, 45.8973°N 8.9382°E 715 m, 3.V.2014, A. Wagner leg (GBIFCH00341000) [ MZL]GoogleMaps . PARATYPES: 16 males, 15 females, 36 nymphs, 4 male subimagines, 2 female subimagines: same sampling data as the holotype; 35 nymphs: same locality as holotype, 18.IV.2014GoogleMaps ; 1 nymph: CH / TI, Stabio, Gaggiolo, 45.8388°N 8.9129°E 379 m, 18.IV.2014GoogleMaps ; 1 nymph: CH / TI, Arzo, Gaggiolo, Arzo, 45.8753°N 8.9448°E 492 m, 18.IV.2014GoogleMaps ; 3 nymphs: CH / TI, Arzo, Gaggiolo, upstream of Arzo, 45.8787°N 8.9494°E 507 m, 18.IV.2014GoogleMaps ; 18 nymphs: IT / LO, Valle Santa Croce, Torrente Molgoretta, 45.7176°N 9.3448°E 304 m, 4.IV.2015; 1 nymph: IT / FV, Buja, Fiume Ledra, 46.2282°N 13.1086°E 175 m, 6.IV.2015; 11 nymphs: IT / FV, Povoletto, Via Reclusane, 46.2658°N 13.3126°E 158 m, 6.IV.2015; 7 nymphs: IT / FV, Savogna, Torrente Rieca, 46.1845°N 13.5821°E 541 m, 6.IV.2015; 24 nymphs: IT / FV, Stregna, Torrente Erbezzo, 46.1287°N 13.5699°E 232 m, 6.IV.2015; 16 nymphs: IT / FV, Prepotto, Fiume Judrio, 46.0826°N 13.5434°E 145 m, 6.IV.2015; 18 nymphs: SL / LC, Kocevje, Reka, 45.5695°N 14.8051°E 512 m, 8.IV.2015GoogleMaps ; 4 nymphs: SL / LC, Kocevje, Gornja Briga, 45.5327°N 14.7935°E 625 m, 8.IV.2015GoogleMaps ; 3 nymphs: SL / LC, Kostel, Kolpa tributary, 45.4646°N 14.8425°E 242 m, 8.IV.2015GoogleMaps ; 2 nymphs: SL / LC, Ribnica, Ribnica tributary, 45.7359°N 14.7103°E 488 m, 8.IV.2015GoogleMaps ; 6 nymphs: SL / LC, Sodrazica, Bistrica, Jelovec, 45.7691°N 14.6222°E 547 m, 8.IV.2015GoogleMaps ; 12 nymphs: SL / LC, Sodrazica, Bistrica, Zimarice, 45.7763°N 14.6111°E 552 m, 8.IV.2015GoogleMaps ; 4 nymphs: SL / LC, Sodrazica, Podklanec, 45.7655°N 14.5811°E 581 m, 8.IV.2015GoogleMaps ; 1 nymph: SL / IC, Bloke, Bloscica , 45.7879°N 14.4761°E 727 m, 8.IV.2015 [all MZL]; 3 male imaginesGoogleMaps , 3 female imagines, 3 nymphs: CH / TI, Meride, Gaggiolo, Spinorolo, 45.8973°N 8.9382°E 616 m, 3.V.2014 [ NHMW]GoogleMaps ; 12 nymphs: IT / FV, Grimaco, Rio Godriana , 46.1574°N 13.5941°E 292 m, 6.IV.2015 [ NHMW]GoogleMaps ; 12 nymphs: SL / LC, Kocevje, Kocevska Reka, 45.5695°N 14.8051°E 512 m, 8.IV.2015 [ NHMW]GoogleMaps .
Other material examined: 1 nymph: CH / TI, Chiasso, Breggia, 45.8407°N 9.0218°E 230 m, 6.III.1948, J. Aubert legGoogleMaps ; 1 nymph: CH / TI, Stabio, Laveggio, 45.8463°N 8.9399°E 340 m, 15.III.1990, B. Jann legGoogleMaps ; 3 nymphs: CH / TI, Meride, Gaggiolo, Spinorolo, 45.8973°N 8.9382°E 616 m, 3.IV.2012, B. Jann legGoogleMaps ; 1 nymph: IT / FV, Buja, Fiume Ledra, Andreuzza, 46.2068°N 13.0947°E 171 m, 6.IV.2015; 4 nymphs: IT / FV, Attimis, Torrente Racchiusano, 46.1733°N 13.3330°E 230 m, 6.IV.2015; 2 nymphs: IT / FV, Savogna, Torrente Rieca, 46.1845°N 13.5821°E 541 m, 6.IV.2015; 3 nymphs: IT / FV, Grimaco, Rio Godriana , 46.1574°N 13.5941°E 292 m, 6.IV.2015; 30 nymphs: IT / FV, San leonardo, Torrente Cosizza, 46.1492°N 13.5638°E 218 m, 6.IV.2015; 1 nymph: IT / FV, Prepotto, Fiume Judrio tributary, 46.0827°N 13.5427°E 147 m, 6.IV.2015; 1 nymph: SL / LCGoogleMaps , Kostel, Kolpa tributary, 45.4646°N 14.8425°E 242 m, 8.IV.2015; 14 nymphs: SL / ICGoogleMaps , Bloke, Bloscica , 45.7879°N 14.4761°E 727 m, 8.IV.2015, A. Wagner leg [ MZL].GoogleMaps
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.