W. P. McCafferty

Insecta, Ephemeroptera: transcontinental range extensions in western North America

Among the 631 valid species of Ephemeroptera (mayflies) that are presently known from North America (McCafferty 2007), relatively few have been known as having more or less continuous (non disjunct) transcontinental distribution patterns from the east coastal provinces of Canada and or east coastal states of the USA to the west coastal provinces of Canada or the west coastal states of the USA or Mexico. The best representation of such distribution patterns is in the family Baetidae, e.g., Acentrella turbida (McDunnough), Baetis bundyae Lehmkuhl (relatively sparse and northern), B. flavistriga McDunnough, B. tricaudatus Dodds, Callibaetis ferrugineus (Walsh), C. fluctuans (Walsh), Diphetor hageni (Eaton), Paracloeodes minutus (Daggy), Procloeon bellum (McDunnough) (relatively sparse and northern), and P. pennulatum (Eaton) (relatively sparse and northern). In other mayfly families such continuous transcontinental patterns are uncommon among species, or in the case of Caenidae, less common. They include such species as Ameletus subnotatus Eaton (northern) (Ameletidae); Baetisca lacustris McDunnough (Baetiscidae); Caenis amica Hagen, C. latipennis Banks, and C. tardata McDunnough (Caenidae); Ephemerella aurivillii (Bengtsson) and E. excrucians Walsh (Ephemerellidae); Ephemera simulans Walker and Hexagenia limbata (Serville) (Ephemeridae); Heptagenia pulla (Clemens) and Maccaffertium terminatum (Walsh) (Heptageniidae); Tricorythodes minutus Traver (eastern records possibly incorrect) (Leptohyphidae); Leptophlebia cupida (Say), L. nebulosa (Walker) and Paraleptophlebia debilis (Walker) (Leptophlebiidae); Metretopus borealis (Eaton) (relatively sparse and northern) (Metretopodidae); Ephoron album (Say) (Polymitarcyidae); and Siphlonurus alternatus (Say) (northern) (Siphlonuridae). In addition to these transcontinental species, there are a few others that are disjunct East and West species that are absent to a considerable extent in central regions of the continent.

Tests of current hypotheses of mayfly (Ephemeroptera) phylogeny using molecular (18s rDNA) data

Abstract Partial 18s rDNA sequences from 22 exemplar mayfly species (Ephemeroptera) representing 20 families were analyzed to obtain a best phylogenetic tree for comparison to previous phylogenetic hypotheses. With respect to relationships among the three major groupings, our molecular data support the hypothesis that Pisciforma and Setisura comprise a monophyletic sister group to the Furcatergalia, rather than the hypothesis that Setisura and Furcatergalia comprise a monophyletic group stemming from the Pisciforma. Within Pisciforma, acceptable trees show that Baetidae separates at the base of the Pisciforma clade. The data suggest that Pisciforma is paraphyletic and do not support the grouping of all Southern hemisphere families as a monophyletic group. An evolutionary sequence favored by the data suggests a grouping of Siphlonuridae, Rallidentidae, Nesameletidae, and Ameletidae and a grouping of Oniscigastridae, Ameletopsidae, and Acanthametropodidae. The data support the monophyly of Setisura (Heptageniidae, Arthropleidae, Pseudironidae, Oligoneuriidae, Isonychiidae, and Coloburiscidae). Within Setisura, a bootstrap/jackknife test places the families Heptageniidae, Arthropleidae, and Pseudironidae in one clade at 100% frequency. Also supported are hypotheses that Pseudironidae is a sister group to a Heptageniidae–Arthropleidae group and that a sister relationship exists between the latter two families. Hypotheses that Pseudironidae separated from other Setisura families at an earlier stage and comprises a sister group to a Heptageniidae–Oligonuriidae lineage or that Pseudironidae should be moved out of Setisura are not supported.

Insecta, Ephemeroptera: range extensions and new Iowa state records

A comprehensive inventory of the mayflies (Ephemeroptera) occurring in the state of Iowa was given by McCafferty et al. (2003), as part of a series on the mayfly fauna of the Great Plains of the U.S.A. Other completed studies in this series have included Nebraska (McCafferty et al. 2001) and North Dakota (Guenther and McCafferty 2005), and South Dakota is in preparation at this time. McCafferty et al. (2003) listed 106 species from Iowa; however, taxonomic revisions, new collections, and errors discovered since then require updating of the list of Iowa mayflies as follows: Due to recent revisions, two species must be deleted from the Iowa list. These include Procleon irrubrum Lowen and Flannagan because it was synonymized with P. viridoculare (Berner), which was already known from Iowa (Wiersema and McCafferty 2004), and Ephemerella inermis Eaton because it was synomyzed with E. excrucians Walsh, which was already known from Iowa (Jacobus and McCafferty 2003). Another synonym that involves Iowa mayflies is that of Centroptilum walshi McDunnough with C. album, although this does not affect the number of species, because only C. walshi was recorded from Iowa. The only other necessary deletion involves Serratella molita (McDunnough), which we have determined was based on a misidentification of immature larvae of Ephemerella needhami McDunnough, a species that was already known from Iowa. Generic recombinations that involved Iowa species since McCafferty et al. (2003) were Wang and McCafferty (2004) as regards Maccaffertium Bednarik [i.e., all previous Stenonema Traver species transferred except S. femoratum (Say)], and McCafferty et al. (2005) as regards Heterocloeon McDunnough [i.e., Acentrella ampla Traver is now H. amplum (Traver)]. These works affected Iowa species names but not numbers. Published additions to the known fauna included Heterocloeon anoka (Daggy) (McCafferty et al. 2004) and C. triangulifer (McDunnough) (Wiersema and McCafferty 2004).

Evaluation of Mayfly Species Originally Described as Baetis Leach (Ephemeroptera: Baetidae) from California

Abstract Eight species of mayflies described in Baetis Leach from California are evaluated for validity, generic classification, and distribution. Taxonomic status quo is maintained for the southwestern Baetis adonis Traver [ =  B. sp. A Morihara and McCafferty,  =  B. caelestis Allen and Murvosh], B. devinctus Traver [synonym of Diphetor hageni (Eaton)], and B. leechi Day [synonym of Fallceon quilleri (Dodds)]. Baetis alius Day is shown to be common in the northwestern U.S.A. and somewhat variable but distinctive as larvae; B. moqui Wiersema, Nelson and Kuehnl is shown to be a junior synonym of B. alius, new synonym. Baetis diablus Day is correctly placed to genus but remains unknown as larvae and has been rarely taken only in California; it is possibly a variant of B. tricaudatus Dodds. Baetis palisadi Mayo is correctly placed to genus, and based on discovered larvae has diagnostic mandibles and labial palpi among rhodani group species; it is apparently endemic to California and of environmental concern. Baetis piscatoris Traver is correctly placed to genus, relatively common in California, and based on discovered larvae is the only known rhodani group species with elongate gills. Baetis sulfurosus Day belongs in Fallceon Waltz and McCafferty, as evidenced by discovered larvae; it is also a junior synonym of the western F. thermophilos (McDunnnough), new combination, new synonym, and is distinct from western congeners by size and color pattern of larvae, and hindwings and subgenital plate of adults.

Mayflies (Insecta: Ephemeroptera) of Nevada, United States of America

Introduction This report provides the first comprehensive list of the species of mayflies that have been taken in the western U.S.A. state of Nevada. Of the western states, Nevada has had the poorest documentation in terms of Ephemeroptera fauna, with only one or very few locales having been recorded for only 38 species. One obvious reason for this historical neglect is that although the state is relatively large at 286,297 square kilometers, it is the driest of all U.S.A. states, resulting in relatively few permanent streams and severely limiting the number of habitats available for mayflies within its deserts. The Great Basin extends into part of the state mainly from Utah; much of western Nevada is in the rain shadow of the Sierra Nevada Mountain Chain; mountains within Nevada tend to be highly isolated and alkaline flats are common. A preliminary survey of the mayflies from the Humboldt River (Fig. 1), which runs east to west in the high desert of the northern part of the state, represents the only previous faunistic study centered over part of Nevada (Baumann and Kondratieff 2000). The first mayfly reported from Nevada was the common western species Siphlonurus occidentalis (Eaton) (Eaton 1885). Banks (1924) added two species, and Traver (1935) added a fourth. All other species were added since 1958.

Mayflies (Insecta: Ephemeroptera) of Yellowstone National Park, U.S.A.

The Ephemeroptera (Insecta) fauna of Yellowstone National Park consists of 46 species in 24 genera among eight families. These species are listed, and fifteen of the species (including collection data) are reported for the first time. Another 13 species have been taken adjacent to the park in Wyoming and Montana and noted as expected to occur in the park.