Abstracts

IDENTIFICATION KEYS

Key to the genera of Ephemerelloidea (Insecta: Ephemeroptera) from Brazil

Chave para os gêneros de Ephemerelloidea (Insecta: Ephemeroptera) do Brasil

Lucimar G. Dias^I,II; Frederico F. Salles^I,II; Cesar N. Francischetti^I,II; Paulo Sérgio F. Ferreira^I

^IMuseu de Entomologia, Departamento de Biologia Animal, Universidade Federal de Viçosa, 36571-000 Viçosa, MG, Brazil. (lucimar@insecta.ufv.br) (ffsalles@insecta.ufv.br) (cnfrancischetti@hotmail.com) (pfiuza@ufv.br)

^IIPrograma de Pós-Graduação em Entomologia, Departamento de Biologia Animal, Universidade Federal de Viçosa, 36571-000 Viçosa, MG, Brazil

ABSTRACT

A key to the Brazilian genera of Ephemerelloidea, nymphs and adults, belonging to the families Coryphoridae, Leptohyphidae and Melanemerellidae is presented. Currently, seven genera of this superfamily are known in Brazil. The Leptohyphidae is the most representative family, with five genera registered from the country, Leptohyphes Eaton, 1882, Leptohyphodes Ulmer, 1920, Traverhyphes Molineri, 2001, Tricorythodes Ulmer, 1920 and Tricorythopsis Traver, 1958. The families Coryphoridae and Melanemerellidae are monotypic, represented by Coryphorus Peters, 1981and Melanemerella Ulmer, 1920.

Key words: Ephemerelloidea, nymphs, adults, illustrated key, Brazil.

RESUMO

Neste trabalho é apresentada uma chave para identificação dos gêneros brasileiros de Ephemerelloidea, ninfas e adultos, pertencentes às famílias Coryphoridae, Leptohyphidae e Melanemerellidae. Atualmente, sete gêneros desta superfamília são conhecidos no Brasil. Leptohyphidae é a família mais representativa, com cinco gêneros registrados para o país, Leptohyphes Eaton, 1882, Leptohyphodes Ulmer, 1920, Traverhyphes Molineri, 2001, Tricorythodes Ulmer, 1920 and Tricorythopsis Traver, 1958. Coryphoridae e Melanemerellidae são monotípicas, representadas por Coryphorus Peters, 1981e Melanemerella Ulmer, 1920.

Palavras-chave: Ephemerelloidea, ninfas, adultos, chave ilustrada, Brasil

Introduction

The superfamily Ephemerelloidea (Ephemeroptera) is a cosmopolitan and very basal group of mayflies (McCafferty & Wang 2000). Together with the superfamily Caenoidea, the Ephemerelloidea are inserted in the suborder Pannota, a group where the mature nymphs have less than half of their forewingpads freely extended beyond their fusion, although the wingpads remain externally recognizable as do the pro- and mesothoracic mesothoracic segments (McCafferty and Edmunds 1979, McCafferty & Wang 2000).

Other representative of Pannota in South America, besides Ephemerelloidea, is the family Caenidae. Despite the similarity between both groups having operculate gills on segment 2, nymphs of South American Ephemerelloidea can be distinguished from those of Caenidae by the absence of filamentous gills 1. The adults of Ephemerelloidea can be differentiated by lacking an ommation on the mesonotum, the vein MP2 of the forewings not extending to the base and not curving from near the base of MP1, and by the vein CuP strongly curved to the inner margin of the wing (McCafferty & Wang 2000).

Of the three families, eleven genera and 70 species of the superfamily Ephemerelloidea represented in South America (Dominguez et al. 2004, Emmerich 2004), all families, seven genera, and 20 species are registered from Brazil (Molineri 2004, Salles et al. 2004). Coryphoridae and Melanemerellidae are represented by one species, each, whereas Leptohyphidae is the most diverse, with five genera and 18 species (Molineri 2004, Salles et al. 2004).

Coryphoridae, represented only by Coryphorus aquilus Peters, 1981, is known in Brazil from the states of Amazonas and Pará, Northern Region. C. aquilus Peters, 1981, is also recorded from Colombia (Peters 1981, Molineri et al. 2002) and French Guiana (Orth et al. 2000).

Melanemerellidae is represented by Melanemerella brasiliana Ulmer, 1920, endemic to Brazil and reported from the states of São Paulo and Espírito Santo, Southeastern Region (Ulmer 1920, Molineri & Domínguez 2003).

With regard to Leptohyphidae, the genera Leptohyphes Eaton, 1982, Tricorythodes Ulmer,1920 and Tricorythopsis Traver, 1958, have five species each. They are widely distributed in Brazil (Banks 1913, Ulmer 1920, Needham & Murphy 1924, Traver 1959, Allen 1967, 1973, Da-Silva 1993, Molineri 1999, 2001a, 2002, 2003). Traverhyphes Molineri, 2001, is represented by two species, one from the Southern Region, and another from the Southeastern Region (Molineri 2001b, 2004). The genus Leptohyphodes Ulmer, 1920, is monotypic and known only from Brazil, being represented by L. inanis (Pictet, 1843). Although the type-locality of L. inanis was referred only to "Brazil" in the original description (Pictet 1843), Traver (1944) described the nymph of the genus, based on specimens from the state of Minas Gerais, Southeastern Region.

In order to contribute to currents and future studies of systematics and ecology of the group in Brazil, a key for the identification of the Brazilian ephemerelloidea genera is necessary. The aim of this paper is to present a key to nymphs and adults of the Ephemerelloidea genera recorded from the country.

Material and methods

All genera of Ephemerelloidea from Brazil were studied for the elaboration of the key. The specimens examined were borrowed from the following institutions: Museu Regional de Entomologia, Universidade Federal de Viçosa, MG and of the Departamento de Zoologia, Instituto de Biologia da Universidade Federal do Rio de Janeiro, RJ. .Drawings were made on white paper with the aid of a Leica camera lucida attached to a MZ8 microscope.

Results

Key to the genera of Ephemerelloidea (Insecta: Ephemeroptera) from Brazil

Acknowledgements

We thank Dr. Carlos Molineri (Faculdade de Ciências Naturales e Instituto Miguel Lillo San Miguel de Tucumán, Argentina) and Dr. Teresinha Maria Castro Della Lúcia (Universidade Federal de Viçosa Minas Gerais, Brasil) for their helpful review of the manuscript. We also thank the Brazilian Council of Scientific and Technological Development (CNPq) for providing funds to Lucimar G. Dias, Frederico F. Salles and Cesar N. Francischetti to conduct postgraduate studies at the Programa de Pós-graduação em Entomologia, Universidade Federal de Viçosa.

Date Received 04/01/2005

Revised 11/22/2005

Accepted 01/01/2006

Nymphs

1. Eyes elevated (Fig. 1); posterolateral projection of abdominal terga 2-5 curved dorsally (Fig. 2); dorsal tubercles present in all regions of the body (Fig. 2) Coryphoridae, Coryphorus

1'. Eyes not elevated (Fig. 3); posterolateral projection of abdominal terga 2-5 not curved dorsally (Fig. 4-6); tubercles usually absent or present in one or two regions of the body (Figs. 4, 5); if tubercles present in all regions of the body, then tubercles paired (Fig. 6) 2

2(1'). Abdominal terga 2-9 with a pair of submedian tubercles, more evident in the abdominal terga 3-9 (Fig. 6); gills with ventral lamellae fringed (Fig. 7); femora strongly expanded (Fig. 8) Melanemerellidae, Melanemerella

2'. Abdominal terga never with paired tubercles (Figs. 4, 5, 10); ventral gills without fringed lamellae (Figs. 13b, 14b); femora generally not expanded (Fig. 9) Leptohyphidae 3

3(2'). Operculate gills subquadrangular, internal margins reaching median line (Fig. 10); gills present on abdominal segments 2-5; eyes of males divided (Fig. 11) Leptohyphodes

3'. Operculate gills triangular, oval or rounded (Figs. 12-15), internal margins not reaching median line; gills present on abdominal segments 26; eyes of males generally not divided 4

4(3'). Body smaller than 4 mm; operculate gills with a weakly sclerotized transversal line (Fig. 15) Tricorythopsis

4'. Body generally larger than 4 mm; operculate gills without a transversal line (Figs. 12-14) 5

5(4'). Operculate gills generally triangular (Fig. 12); if operculate gills ovoid, then femora circular and bordered with long setae (Fig. 16) ...Tricorythodes

5'. Operculate gills ovoid (Figs. 13, 14); femora never bordered with long setae ...6

6(5'). Ventral lamellae of operculate gills with a basal beak-like process (Fig. 13b); operculate gills without dorsal ribs (Fig. 13a) Leptohyphes

6'. Ventral lamellae of operculate gills without a basal beak-like process (Fig. 14b); operculate gills generally with one or two dorsal ribs (Fig. 14a) ...Traverhyphes

Adults

1. Forewings with 2-3 detached marginal intercalaries between apex of main intercalary veins (Fig. 17a); hind wings present in both sexes (Fig. 17b) ...Melanemerellidae, Melanemerella

1'. Forewings without marginal intercalaries (Fig.18a, 20, 23, 24); hind wings variable, present only in males, absent in both sexes, or, rarely, present in both sexes ...2

2(1'). Compound eyes of male greatly enlarged and undivided, separated on dorsum of head by width of an eye (Fig. 19); cubital area of fore wings without intercalaries (Fig. 20); penis large, fused and distally broadened (Fig. 21) ...Coryphoridae, Coryphorus

2'. Eyes of male similar to females, usually not enlarged (Fig. 22); if so, then eyes divided and close to each other in dorsal view; intercalaries present on cubital area (Figs. 18, 23, 24); penis not as above (Figs. 25-29) ...Leptohyphidae ...3

3(2'). Mesoscutellum with relatively long membranous filaments (Fig. 30); base of male forewings not broadened (Fig. 18) ...4

3'. Mesoscutellum without membranous filaments (Fig. 31); male forewings broadened at base (Fig.23, 24) ...6

4(3). Eyes of males divided (Fig. 32); forceps two-segmented; hind wings absent in both sexes ...Leptohyphodes

4'. Eyes of males usually not divided (Fig. 22); forceps three-segmented; hind wings present at least in males (Fig. 18) ...5

5(4'). Penis "Y" shaped, with apical spine and without dorsal spine (Fig. 25) ...Leptohyphes

5'. Penis not as above (almost totally fused), without apical spine and with dorsal spine (Fig. 26, 27) Traverhyphes

6(5'). Forceps three-segmented, basal swelling usually present at base of second joint (Fig. 28) ...Tricorythodes

6'. Forceps two-segmented, basal swelling absent at base of second joint (Fig. 29) Tricorythopsis

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