Campsurus truncatus Ulmer

Molineri, C., Salles, F. F. & Emmerich, D., 2015, Revision of Campsurus violaceus species group (Ephemeroptera: Polymitarcyidae) with new synonymies and nomina dubia in Campsurus Eaton, 1868, Zootaxa 3920 (1), pp. 51-68 : 61-62

Campsurus truncatus Ulmer

( Figs. 4 , 28−37 )

Campsurus truncatus Ulmer, 1920: 2 (male); Lestage, 1923: 123; Puthz, 1973: 94 (male). Campsurus mahunkai Puthz, 1973: 94 (male, female, egg); Domínguez et al. 2006: 575. NEW SYNONYM Campsurus melanocephalus Pereira & Da-Silva 1991: 322 (male, female, nymph); Domínguez et al. 2006: 575. NEW

SYNONYM

Type material. C. truncatus : photographs of 1 male imago, pinned, in good condition, with four labels indicating: "Espirito-Santo, Brasil, ex. coll. Fruhstoffer" (green), "coll. Ulmer Eing.Nr. 6−63" (white), "Paratypoid" (red), and "Mus. Wein 1921" (white). Deposited in Zoologisches Museum Hamburg.

Additional material. BRAZIL (in CZNC, except otherwise indicated): 2 male and 1 female imagos from Espírito Santo, Sooretama, São José river, 23.i.2012, light trap; 5 male and 1 female imagos from Espírito Santo, Santa Teresa, Nova Lombardia, Capitel de Santo Antônio, Grande stream, 704 m, 24.x.2008, light trap, CEUNES col., 19º 55' 30.1"–40º 33' 21.9"; 5 male imagos from Espírito Santo, Santa Teresa, Nova Lombardia, Capitel de Santo Antônio, Grande stream, 705 m, 26.x.2008, light trap, CEUNES col., 19º 52' 31.7 "− 40º 31' 47.3"; 1 male and 1 female imagos from Espírito Santo, Alfredo Chaves, Nova Mantova, Sede, 371 m, 4.ix.2007, light trap, RB col., 20º 39' 41.7"–40º 50' 24.3"; 3 male and 1 female imagos from Espírito Santo, Sooretama, São José river, 9.ix.2011, light trap; 2 male and 10 female imagos from Restinga de Jurubatiba National Park, Quissamã, RJ, Lagoa Vergueiro, AL Netto-Ferreira; 20 male adults from Amazonas, Jacitara lake, da Paciência island, 19.ix.2003, UV light trap; 20 male adults from Amazonas, Jacitara lake, da Paciência Island, 19.ix.2003, UV light trap; 2 male and 1 female imago from Amazonas, Codajás, Urucurizinho, lake, light trap, 16.ix.2003; 4 male and 18 female imagos from Goiás, Mineiros, stream, 514 m, 24.ii.2012, Pennsylvania trap, LF Sgarbi, APM Santos, E. Raimundi, 17º 12' 35.9"–52º 39' 38.9"; 9 male and 21 female imagos from Goiás, Caiapônia, 1.iii.2012; 2 nymphs (1 pharate male subimago) from rio Grande dam, 27.vii.2011; 10 nymphs from Cachoeira de Cima dam, 18.viii.2011; 1 nymph from São Paulo, Billings dam, 26.viii.2010, 2 nymphs from Cachoeira de Cima dam, 18.viii.2011; 15 nymphs from São Paulo, Billings dam, 7.vii.2009; 15 nymphs from São Paulo, res. Salto Grande (americana), sublitoral, 16.vi.2009; 8 male imagos from Piauí, 01.vi.2011, Domingos Mourão, Vila Cachoeirinha, road to Domingos Mourão, S 04º10'06.2" W 41º34'55.0", 1.vi.2011, P.V. Cruz Col. ( INPA); 2 male and 1 female adults from São Paulo, Riberão Preto, USP, Monte Alegre lake, 15.viii.2007, Mariano, Calor & Pinho cols.; 1 mature male nymph from Minas Gerais, Poço de Caldas, Águas Claras dam, 20.xi.2013, P. Z. Pamplin col. (IBN), and 1 female mature nymph same data except date, 11.vii.2013.

COLOMBIA-PERU border: 1 male imago (IBN) from Amazonas, Caballo Cocha, light trap, M.E. Rincón col. (without additional data). COLOMBIA: 1 male imago (IBN) from Amazonas, Puerto Nariño, Tarapoto lake, 93 m, 4.ii.1999, light trap 18−20 h, S 3º 43' 43" – W 70º 25' 17", Zúñiga, Domínguez, Molineri cols.; 3 male and 2 female adults (IBN) from Amazonas, Amacayacu National Park, 93 m, 1.ii.1999, S 3º 48' 47" – W 70º 17' 06", 93 m, light trap 17−19 h, Zúñiga, Domínguez, Molineri cols.; 2 male imagos (MUSENUV) from Amazonas, Leticia, road to Tarapaca, stream at km 15, 93 m, S 4º 5' 41" – W 69º 59' 01", 11.ii.1999, light trap 4−6 h, Zúñiga, Domínguez, Molineri cols.

Distribution. Bolivia, Brazil, Colombia, Peru.

Diagnosis. Campsurus truncatus can be separated from the other species of the genus by the following combination of characters: 1) pedestals elongate, with projected acute outer corner ("op" in Figs. 4 and 28 ), generally as projected as the inner one ("ip" in Figs. 4 and 28 ), but variable ( Figs. 31−33 ); 2) penes relatively stout, with rounded "thumb", and somewhat truncated apex ( Figs. 28−30 ); 3) female socket with relatively long and narrow anterior furrow ("f" in Figs. 34−35 ). Nymphs may be distinguishable by the row of denticles on the inner margin of mandibular tusks formed by 6−8 denticles that increase in size basally, the most basal one is only 1.5 times larger than the previous one ( Figs. 36−37 ); between each one of these tubercles two stout setae are present ( Figs. 36−37 ). The eggs are not distinguishable from other species in the violaceus group.

Male imago. Length (n=7, mm): body, 9.0−16.5; FW, 9.0−14.0; HW, 4.1−6.5; cerci, 19.5−34.0; foreleg, 4.2−6.2 (total length without coxa). Foreleg, ratio of segments in relation to femur (1.4 mm): femur (1), tibia (0.8−1.1), tarsomere 1 (0.1); tarsomere 2(0.2−0.5); tarsomere 3 (0.3−0.5), tarsomere 4 (0.3−0.5), tarsomere 5 (0.3−0.5), short claw (0.1−0.3), long claw (0.2−0.4). Tarsal segments 2−4 subequal, slightly shorter than 5 (the longest), tarsomere 1 very short. Genitalia ( Fig. 4 , 28−33 ): penes stout, with rounded "thumb", apex truncated; pedestal subrectangular (but variable, Figs. 31−33 ), always the outer margin acutely pointed and subequal in length to the more rounded (and wider) inner margin; outer subtriangular outgrowth of the pyramidal base rounded as in Figs. 28−30 .

Female subimago. Length: body, 10.0−11.7; FW, 10.0−11.8; HW, 4.2−5.0; cerci, 2.5−3.0. Abdomen. Sternum VIII with single socket, anterior to it a long and slender furrow is present ( Figs. 34−35 ).

Nymph. As in the description given for C. violaceus , exceptions follow:

Mature nymph. Length of male (mm): body, 14.5; terminal filament, 10.0; cerci, 13.5. Length of female (mm): body, 24.0; terminal filament and cerci broken off and lost. General coloration light brownish yellow (both individuals are pharate subimagos). Mandibular tusks with 6−8 denticles on inner margin, the most basal one slightly larger (1.5 x) than the others ( Figs. 36−37 ); paired stout setae are intercalated between these denticles. Abdomen. Thin blackish medial line present on terga II −IX. Gills 2−7 with ventral lobe paler than dorsal one, fringes paler than lamella.

Discussion. Campsurus truncatus is here considered the senior synonym of C. mahunkai and C. melanocephalus because all of them share the same male genitalia, particularly the form of pedestals and forceps. Campsurus truncatus , known from all the stages, presents male genitalia similar to C. violaceus , except that penes are shorter and more robust with a truncate apex, pedestals are different in form, with both posterolateral corners similar in length, the outer thinner than the inner one. Characters given by Puthz (1973) and Pereira & da Silva (1991) to distinguish C. mahunkai and C. melanocephalus respectively, showed to be variable in a larger series from different localities studied by us. For example the black color on head and other dorsal portions of adult C. melanocephalus is the main defining character used by Pereira & da Silva to distinguish this species, but specimens showing pale to very obscure coloration but with identical genitalia are present in different series studied by us. Puthz (1973) differentiated C. mahunkai from C. truncatus (from which he studied the type) in the form of hind margin of sternum IX (truncate in the first, slightly concave in the second) and base of penis (more protruded in the second), but such differences were encountered by us in different males of the same population, thus proving to be inside the normal intraspecific variability. Even in C. truncatus "paratypoids" (two pinned male imagos at ZMH) the two conditions of the hind margin of sternum IX are present.

We have only studied two ready to molt nymphs that seems undistinguishable from C. violaceus at this time, except for the relative smaller most basal denticle on the inner margin of mandibular tusk of C. truncatus . Mandibular tusks of these nymphs present a regular denticulation on the inner margin, differing from the original description (as C. melanocephalus ) where Pereira & da Silva (1991) characterize the species as having an "irregular denticulation".

Figures

FIGURES 1 − 4. Photographs of male genitalia (types): 1, C. violaceus holotype slide (CUIC); 2, C. meyeri paratype (rehydrated and mounted on slide MACN); 3, C. notatus holotype slide (CUIC); 4, C. truncatus paratypoid (pinned, ZMH). Abbreviations: ip = inner projection (pedestal); op = outer projection (pedestal); p = penes; pb = pyramidal base (penes); t = ” thumb ” (penes).

FIGURES 28 − 37. C. truncatus. Imago: 28, male genitalia, v. v. (Colombian specimen); 29, same (slide IBN 28 CM); 30, same (slide IBN 31 CM); 31 − 33, pedestals, variations, v. v.; 34, detail of female sockets; 35, female sternum VIII. Nymph: 36, outline of inner edge of left mandibular tusk; 37, left mandibular tusk. Abbreviations: f = furrow; ip = inner projection (pedestal); op = outer projection (pedestal); p = penes; pb = pyramidal base (penes); s = socket; st = subbasal tubercle; t = " thumb " (penes).