Manuel L. Pescador

Phylogenetic Relationships and Zoogeography of Cool-Adapted Leptophlebiidae (Ephemeroptera) in Southern South America

Twelve cool-adapted leptophlebiid genera are known to occur in southern South America. Analysis of the external morphology of both adults and nymphs indicated that cool-adapted South American leptophlebiids represent five distinct phyletic lineages, namely: the Hapsiphlebia,, Penaphlebia Atalonella, New Genus A and Meridialaris lineages. All of these, except the Penaphlebia lineage, presently include some genera from other areas of the Southern Hemisphere. Phylogenetic evidence indicates that cool-adapted South American Leptophlebiidae are related to confamilials occurring in the mountain waters of Southeastern Australia (including Tasmania), New Zealand, New Caledonia, Madagascar and South Africa. This study revealed that most genera from South America are more closely related to genera from Australia than to those occurring in the other continents.

Four New Genera of Leptophlebiidae (Ephemeroptera: Atalophlebiinae) from Southern South America

Abstract Four new monotypic genera of Leptophlebiidae, Archethraulodes, Demoulinellus, Rhigotopus and Secochela are established. Four new species are described. Three, Archethraulodes spatulus, Rhigotopus andinensis and Secochela illiesi are described from imagines. One, Demoulinellus coloratus is known from both imagines and nymph. Descriptions of the eggs of genera are included.

Biosystematics of the Genus Massartella Lestage (Ephemeroptera: Leptophlebiidae: Atalophlebiinae) from South America

The genus Massartella and the species M. alegrettae Ulmer and M. brieni (Lestage) (= M. fruhstorfferi Ulmer, New Synonymy) are redescribed. The male subimagines of M. alegrettae and M. brieni and the nymph of the latter are described for the first time. A new species, M. venezuelensis is described from nymph and female subimago. Two immature Massartella nymphs, unassociated with adults and not identifiable to species, have been collected in Argentina. Illustrated keys for the nymphs and imagines are provided for the species.

Mayflies (Insecta: Ephemeroptera) from Venezuela

A list of the known mayfly (Ephemeroptera) fauna of Venezuela is given, along with the states and bioregions from which each species is known. Depositions of the type specimens of each species are also listed.

The Status of the Taxonomy of the Mayfly (Ephemeroptera) Fauna of South America

A total of 375 nominal species representing 91 genera in 13 families are presently known in South America. The family Leptophlebiidae is presently the most diverse group representing 38 % of the mayfly genera and 30 % of the species in the region. Brazil and Argentina have the highest number of mayfly taxa known followed distantly by Peru and Chile. Approximately 60 % of the South American genera and 80 % of the species are endemic to the region. A high percentage of taxa that are known from only one life stage, disparity of the fauna known from different countries, and lack of communication and information exchange among mayfly workers are some of the problems with mayfly taxonomic studies of the region.

MAYFLIES (EPHEMEROPTERA) OF NORTH CAROLINA AND SOUTH CAROLINA : AN UPDATE

A total of 204 valid species representing 56 genera in 18 families of mayflies are known to occur in North Carolina and South Carolina. Twenty-six of the 182 species of mayflies that are known from North Carolina are reported for the first time. South Carolina has 170 species of mayflies recorded, of which 26 are new state records. Taxonomic changes relevant to the mayfly fauna of both states are discussed.

The adult and redefinition of the genus Prebaetodes Lugo-Ortiz & McCafferty (Ephemeroptera: Baetidae), with description of a new species from Venezuela

The adult stage of Prebaetodes Lugo-Ortiz & McCafferty is described for the first time based on reared specimens from Venezuela. The adults of the genus can be distinguished from other genera of South American Baetidae by the following combination of characters: paired marginal intercalaries of forewings, anal area rounded and relatively narrow; hind wings absent; male eyes turbinate, contiguous basally and slightly separated dorsally; segment I of forceps without distomedial projection, segment III elongated and uniformly slender. Additionally, a new species, P. meridinensis is described based on nymphs and imagines, and notes on its biology are included. The genus is herein redefined based on variations of characters observed in the new species and the adult generic description.

Gonserellus: A new genus of Leptophlebiidae (Ephemeroptera) from Southern South America

Gonserellus atopus from Chile, a new genus and species, is described based on the mature nymph. The nymph of Gonserellus is distinguished from that of other leptophlebiid genera by having a well‐developed galea‐Iacinial tusk on the maxilla and prominent bipectinate spines on the tibiae. Gonserellus appears to be a member of the Nousia lineage based on a number of shared derived nymphal characters.

Systematics of the Nearctic Genus Pseudiron (Ephemeroptera: Heptageniidae: Pseudironinae)

The genus Pseudiron is redescribed and the subimagos are described for the first time. Pseudiron meridionalis Traver is synonymized with P. centralis McDunnough leaving Pseudiron a monotypic genus. Pseudiron centralis is redefined, and its biology, ecology, distribution, and geographic variation in the Central United States and Canada is discussed.

Evolution of Baetiscidae (Ephemeroptera): current state of knowledge of the family

Recent discovery and description of fossil Baetiscidae has dramatically changed the biogeographical and evolutionary perspective of the family. Since the mid-eighteenth century until recently, the family has been known only from the Nearctic realm and all extant species of the family still remain geographically limited to this region. Here, we present the first parsimony algorithm generated cladistic analysis of the phylogeny of Baetisca based on external morphological characters of both larvae and adults. The results are compared with the previously published phylogeny of the genus and differences between the two studies are discussed. The southeastern United States is the centre of biodiversity of the genus where 11 of the 12 currently known nominal species have been reported. Biogeographical and evolutionary implications of the current geographic range of extant Baetisca and fossil species are discussed.