Leptohyphes cornutus Allen

Nascimento, Jeane M. C., Molineri, Carlos & Salles, Frederico F., 2014, Redescription of Leptohyphes cornutus Allen, 1967 (Ephemeroptera: Leptohyphidae) and description of three related new species, Zootaxa 3893 (3), pp. 397-415 : 413-414

Leptohyphes cornutus Allen

Leptohyphes cornutus Allen 1967: 357 ; Molineri 2003: 55; Dias et al. (2007a): 215; Domínguez et al. (2006): 269.

Material examined. Holotype slides ( FAMU) from Brazil, rio Irany (?), iv.1963, F. Plaumann ( Irani river is located near Nova Teutonia in Santa Catarina state). Additional material: 1 nymph ( CZNC), Brazil, SANTA CATARINA, Passos Maia, Rio Chapecozinho, S 26°46'1.66" / W 51°49'49.79", 1031 m.a.s.l., 13/iii/2009, F. Salles, E. Raimundi cols.; 2 immature nymphs from Argentina, Misiones, Uruzú stream, S 25°º 51 29 / W 54º 10 10, 322m, 17.i.2004, E. Dominguez col (IBN); 2 nymphs (1 nearly mature) and 1 nymphal exuviae (reared male) same locality (IBN), 23–25/XI/1998, Domínguez et al. cols.; 2 immature nymphs (IBN) same locality, 7–11.xii.1999, C. Molineri; and 2 immature nymphs (IBN) from Misiones, Parque Provincial Esmeralda, S 26º 38 47.8 / W53º 59 54.9, 478 m, 23.xi.2009, E. Dominguez & C. Nieto cols.

Diagnosis ( Table 1 ). i) paired tubercles on head (2 pairs), pronotum (two pairs, one very small), and mesonotum (two pairs), abdominal terga without paired tubercles nor remnants of them (in some nymphs a posteromedial small hump is present in terga VII–VIII), and abdominal terga IV–VIII present a pair of sublateral blunt spines; ii) fore femur length/maximum width, 1.4 (very immature) to 1.8 (mature); iii) fore margin of middle and hind femora without spines, hind margin (in mature or nearly mature nymphs) with 4 (middle femur) to 20 (hind femur) rounded and stout spine-like setae on elevated sockets, hind femur with outer apex strongly projected (not so strongly in mature nymphs) bearing 1 or 2 distal spines; iv) tarsal claws denticulation 4 (immature) to 11 (mature) marginal denticles and 1 subdistal submarginal denticle; v) middle coxa with acute projection on dorsum (in mature nymphs a smaller projection is also present in hind coxa); vi) hind wing pads present in females; vii) gill formula 3/10/8 /8/5, gill V without ventral extension on dorsal lamella.

Distribution. Argentina (Misiones), Brazil (Santa Catarina, Goiás, Minas Gerais (Araponga, Sao Paulo).

Discussion. Molineri (2003) incorrectly listed a small nymph (slide IBN608CM) as L. cornutus , this nymph was collected from Brazil, Rio de Janeiro, 950 m, Nova Friburgo, municipal water supply, 20.iv.1977, C.M. & O.S. Flint cols. (IBN). This very immature specimen presents the character states now associated with L. airuoca sp. nov., and thus it is listed and diagnosed under this species. As a consequence L. cornutus is no longer recorded from Rio de Janeiro state as listed in Molineri (2003), Dias et al. (2007a) and Domínguez et al. (2006). Dias et al. (2007a, b) recorded this species in Espírito Santo, São Paulo and Minas Gerais. We have not studied the material from Sao Paulo, and only partially that of Minas Gerais, thus we only can eliminate the record from Espirito Santo in the distributional list of this species. The nymphs of L. cornutus are readily distinguished from the other species described here by the presence of two pairs of tubercles in mesonotum (1 or 3 pairs in the others), and by the absence of median tubercles in abdominal terga (single or paired tubercles in the others) ( Table 1 ).

There is a possibility that some of the new species described here actually are the nymphal form of Leptohyphes mollipes Needham & Murphy (1924) only known from adults from a dubious locality in Brazil. Nevertheless we prefer to describe the new species because the adult stage of the genus presents very few characters of specific value, and thus species known only from adults are of restricted importance.

Tables

TABLE 1. Comparison between species and specimens from different localities and nymphal stages.

	Pronotum (tubercles)	Mesonotum (tubercles)	Abdomen (tubercles)	Pointed coxal projections	Femur 1, ratio length/ max width	Ratio length tibia 1 / tarsus 1	Denticles foretarsal claw
L. cornutillus	2 pairs	3 pairs	remnants	No	2.1-2.3	2.1	6+1
L. nebulosus	1 pair	1 pair	paired	Middle	1.6	2	5+1
L. cornutus Allen 1967 (type)	“present”	“present”	No	Middle	1.5	1.5	4-5+ 1
L. cornutus (Misiones, IBN198CM) fully- grown	2 pairs, the anterior very small	2 pairs	No	Middle & small hind	1.8	1.9	6-11+1
L. cornutus (Misiones, IBN609CM) immature nymph	2 pairs, the anterior very small	2 pairs	No	Middle	1.4	1.6	4+1
L. cornutus (Misiones, IBN610CM) half-grown	2 pairs, the anterior very small	2 pairs	No	Middle	1.6	1.8	7+1
L. airuoca half-grown, type	2 pairs subequal	1 pair	Single, terga VI to IX	No	1.9-2.0	?	4+0
L. airuoca (RJ, IBN608CM) very immature	2 pairs subequal	1 pair	single, tergum VIII	No	1.7	1.9	4+0
Concluding remarks