C. Riley Nelson

A phylogeny of robber flies (Diptera: Asilidae) at the subfamilial level: molecular evidence

We present the first formal analysis of phylogenetic relationships among the Asilidae, based on four genes: 16S rDNA, 18S rDNA, 28S rDNA, and cytochrome oxidase II. Twenty-six ingroup taxa representing 11 of the 12 described subfamilies were selected to produce a phylogenetic estimate of asilid subfamilial relationships via optimization alignment, parsimony, and maximum likelihood techniques. Phylogenetic analyses support the monophyly of Asilidae with Leptogastrinae as the most basal robber fly lineage. Apocleinae+(Asilinae+Ommatiinae) is supported as monophyletic. The laphriinae-group (Laphriinae+Laphystiinae) and the dasypogoninae-group (Dasypogoninae+Stenopogoninae+Stichopogoninae+ Trigonomiminae) are paraphyletic. These results suggest that current subfamilial classification only partially reflects robber fly phylogeny, indicating the need for further phylogenetic investigation of this group.

New unadorned hadrosaurine hadrosaurid (Dinosauria, Ornithopoda) from the Campanian of North America

ABSTRACT A new hadrosaurid dinosaur, Acristavus gagslarsoni, is here named on the basis of several autapomorphic characteristics of the frontal, postorbital, and dentary. Acristavus is a member of the newly erected clade Brachylophosaurini, which along with its other members, Brachylophosaurus and Maiasaura, constitutes the earliest hadrosaurine hadrosaurid clade. The new taxon occurred approximately 79 million years ago and has been recovered from the Two Medicine Formation of western Montana and nearly simultaneously in the Wahweap Formation of southern Utah. Corresponding with its age and relationship to the other members of the Brachylophosaurini, it is not surprising that Acristavus possesses traits seen in both Brachylophosaurus and Maiasaura, but not necessarily shared between them. One of the most interesting morphological features of Acristavus is the lack of cranial osteological ornamentation, which is in stark contrast to every other hadrosaurid dinosaur except Edmontosaurus. Combining stratigraphic and phylogenetic data from Acristavus yields support for the hypothesis that the hadrosaurid ancestor did not possess cranial ornamentation, and that the subfamilies Hadrosaurinae and Lambeosaurinae each independently developed display structures.

Climate oscillations, glacial refugia, and dispersal ability: factors influencing the genetic structure of the least salmonfly, Pteronarcella badia (Plecoptera), in Western North America

BackgroundPhylogeographic studies of aquatic insects provide valuable insights into mechanisms that shape the genetic structure of communities, yet studies that include broad geographic areas are uncommon for this group. We conducted a broad scale phylogeographic analysis of the least salmonfly Pteronarcella badia (Plecoptera) across western North America. We tested hypotheses related to mode of dispersal and the influence of historic climate oscillations on population genetic structure. In order to generate a larger mitochondrial data set, we used 454 sequencing to reconstruct the complete mitochondrial genome in the early stages of the project.ResultsOur analysis revealed high levels of population structure with several deeply divergent clades present across the sample area. Evidence from five mitochondrial genes and one nuclear locus identified a potentially cryptic lineage in the Pacific Northwest. Gene flow estimates and geographic clade distributions suggest that overland flight during the winged adult stage is an important dispersal mechanism for this taxon. We found evidence of multiple glacial refugia across the species distribution and signs of secondary contact within and among major clades.ConclusionsThis study provides a basis for future studies of aquatic insect phylogeography at the inter-basin scale in western North America. Our findings add to an understanding of the role of historical climate isolations in shaping assemblages of aquatic insects in this region. We identified several geographic areas that may have historical importance for other aquatic organisms with similar distributions and dispersal strategies as P. badia. This work adds to the ever-growing list of studies that highlight the potential of next-generation DNA sequencing in a phylogenetic context to improve molecular data sets from understudied groups.

Unique reproductive characteristics of Lake Tahoe’s Capnia lacustra (Plecoptera:Capniidae), a stonefly in decline

Capnia lacustra Jewett 1965, a wingless stonefly found in the deep benthic environment of Lake Tahoe, has declined in density and distribution since the 1960s. We investigated its life-history characteristics, including its pattern of voltinism. We also compared C. lacustra’s current density and distribution in plant beds to that in the 1960s. Size-frequency analysis showed the development of 2 asynchronous reproductive cohorts, each with a life-cycle duration of ∼1 y. The presence of eggs within mature females in May and November confirmed that spring and autumn cohorts develop simultaneously. We found eggs throughout the abdomen, thorax, and head of C. lacustra females. Females from the autumn cohort were viviparous, whereas the spring cohort was oviparous. This is the first time facultative viviparity has been described for Plecoptera. Capnia lacustra’s unique life history probably is driven by relatively stable temperatures and food availability in Chara beds in the lake. Capnia lacustra currently is known to occur only in 3 areas of Lake Tahoe, whereas it was widespread in the 1960s. It has maintained high densities at 1 of the sites, Camp Richardson, which has an extensive and dense bed of the macroalga Chara. Capnia lacustra’s dependence on Chara, which is declining in geographic and depth distribution in the lake, may have led to the observed declines in density and distribution of this remarkable stonefly.

Diversity, Phenology, and Elevational Distribution of Ephemeroptera, Plecoptera, and Trichoptera in American Fork Canyon, Utah

ABSTRACT. Although the aquatic insect fauna of Utah and their associated adult forms are well documented taxonomically and biogeographically, little is known about seasonal and elevational patterns of aquatic insect diversity in individual Wasatch streams. We selected the American Fork River, a relatively pristine stream with little anthropogenic disturbance, as our target stream to investigate elevational distribution and seasonal phenology of adult forms of Ephemeroptera, Plecoptera, and Trichoptera (EPT). From April to October in 2003 through 2005, a total of 71 adult forms of EPT species were documented along the American Fork River. No single sampling period captured more than 30 species, and richness per sampling period averaged 8 species for all sites combined. The mid-elevational site (1862 msl) was the most species rich, with 54 species of transitional fauna captured along the elevational gradient. As such, this site is an important reference for maximum potential richness. Plecoptera emerged earlier in the year than Trichoptera, with the Plecoptera-dominated community being most rich in June, and the Trichoptera-dominated community being most rich in August. We observed 3 distinct seasonal species suites and 3 elevationally zoned community assemblages that were recurrent in their timing and location from year to year. The compiled species lists, life histories, and preliminary investigation of ecological trends provide a firm basis for further systematic studies on the ecology, water quality, and conservation of the aquatic insects of the American Fork River and similar mountain streams, particularly in the Wasatch region.

Systematics of the Capnia californica species group, including a morphological phylogeny, zoogeography, and description of Capnia kersti, new species (Plecoptera: Capniidae)

Abstract Within the genus Capnia, the Capnia californica species group is demonstrated to be monophyletic and limited in zoogeographic distribution to western North America. A new species, Capnia kersti, is described. It is remarkable in coming from central Oregon, well north of the known range of all other closely related members of the group. Characteristics for diagnosing the new species from all others in the genus are given. A revised key to the C. californica group, key illustrations, and distribution maps for all species in the group are given. Fully resolved phylogenies of the group based on a matrix of morphological characters are given. The distribution of characters on the most parsimonious tree is discussed. Two types of distribution for members of the group are summarized, one along the coast of western North America and a second that is expanded to include the desert southwest. A large gap between closely related forms is noted in the region of the current Mohave Desert. This gap correlates to a date of between 8 and 15 ka (ka is 1,000 yr before present) for the desertification of this area.

The albibarbis-complex of Efferia Coquillett, 1910 from the Grand Canyon region, southwestern U.S.A., with three new species and new distribution records (Diptera: Asilidae)

Abstract Six species of the albibarbis complex of Efferia Coquillett are reported from the Grand Canyon ecoregion on the southern Colorado Plateau in northern Arizona. The terminalia of E. albibarbis (Macquart), E. bicolor (Bellardi) E. carbonaria sp. nov., E. fisheri sp. nov., E. tapeats sp. nov., and E. zonata (Hine) are figured and compared with congeners. Efferia peralta Wilcox and E. vertebrata (Bromley) are included as comparisons and possible members of the Grand Canyon faunas. The range of E. bicolor has been extended northward from central Arizona to within 51.5 km of the south rim of the Grand Canyon and into Nye County, Nevada. Efferia fisheri is recorded along the southern edge of the plateau at Payson, AZ, 169 km south of the GCNP. Taxonomic and distribution notes are provided. Wilcoxs key of this complex is revised to include all species described since his publication. Four of the six species overlap in low-elevation perennial stream riparian zones and in adjacent colluvial brecchia habitats in the Grand Canyon region. Efferia bicolor, E. fisheri, and E. zonata overlap at higher elevations.

Fly family diversity shows evidence of livestock grazing pressure in Mongolia (Insecta: Diptera)

Members of the insect order Diptera respond differentially to environmental changes and may play an important role in understanding the effects that livestock grazing disturbances have on biodiversity. Here we examine how increasing grazing pressures on the Mongolian steppe affect Diptera diversity and abundance. Using 2334 yellow pan traps, we sampled a total of 132 sites over four years to collect 17,348 flies. We compared fly diversity and abundance at five levels of livestock grazing. We observed that fly family diversity decreased in heavily grazed sites and that diptera communities at sites with intense grazing have proportionally higher prevalence of taxa from the families Muscidae, Sepsidae, Ephydridae, Chloropidae, and Tachinidae, two of which are often associated with animal waste. Chironomidae, Ceratopogonidae, Sarcophagidae, and Sciaridae are most prevalent at sites with very little or no grazing, and Anthomyiidae, Calliphoridae, Carnidae, Cecidomyiidae, Dolichopodidae, Empididae, Scatopsidae and Sphaeroceridae are most often encountered at sites with intermediate amounts of grazing. Observing changes in a few guilds of fly families at different grazing levels is beneficial in understanding human effects on fly diversity.

Peregrine Quest: From a Naturalist's Field Notebook by Clayton M. White

It is good to know what you like early in your life; then you can accomplish much with it. Clayton White found that he liked falcons early in his life and has been traveling the world or, as he says, following “trails” ever since: “In a sense, one’s life experiences are like a series of interconnected paths, or trails, each leading from the past to the future in directions that are sometimes familiar, sometimes unexpected. This book is about those trails and how I have found meaning in life’s expressions” [page xxi]. It is very important to read the prologue of this book because it provides the reader with a frame of reference for the author’s experiences as he presents bits, chops, chips, and flakes along the way. Oh, that we all better understood our motivations for doing the things we do each day! The lifetime of biological research summarized in the field notebook section comes out as brilliant flashes of insight scattered in the mundane movements and data recording of a field biologist’s day-to-day life. This book is worth reading for those insights alone. Early on, White witnessed the decline of the Peregrine Falcon to dangerously low population numbers across broad bands of its range. He clearly admits that this decline allowed him to see the world through the eyes of this wandering bird, which is probably the most widely distributed species of terrestrial vertebrate on earth. His own peregrinations for this wandering bird have taken him nearly from pole to pole. From Alaska and the Aleutians to Argentina, Australia, the Amazon, central Asia, and Fiji, White has literally gone to land’s end to understand this bird on its own cliffs. In all these travels, Alaska clearly holds a special place in White’s psyche. Perhaps the interconnected trails he speaks of earlier converge there, as do the ranges of several of the Peregrine Falcon subspecies that he loves. Others might have found professional, parsimonious, and efficient satisfaction by learning of relatedness from tubes of tissue in a laboratory. White first went to the birds on the cliffs, riverbends, and islands where he filled the tubes; then he sought secondary confirmation (or sometimes refutation) of his ideas about phylogeny, ecology, and life history from the lab-bench sequencers and computer simulators. He experienced the search in real time and space, and loved the research at scales not relevant to day-to-day encounters, but informative in a reductionist modality. He sought out collaborators for his field research and for the lab work as well. A thoughtful reading of his sections labeled “Side Trips” and “Postscripts” will give you access to White’s aesthetic, earned by working both with falcons and with an amazingly wide variety of people. Because he worked with such a high-profile conservation icon as the Peregrine Falcon, White can also speak of dealing firsthand with politicos and decision-makers. He pulls few punches in noting the relative intelligence and honesty of the various players with whom he rubbed shoulders during his quest to help the falcons recover from decline. And amid all this self-interest, bias, and fervor, White concludes that the amazing return of the Peregrine Falcon from the brink of annihilation to the brink of building cornices and far-flung cliffs worldwide may have simply been a natural event, not necessarily mediated by the watchful care, which scientists predicted would be needed based on results from countless surveys, artificial rearings, and transplantations. However, it is quite clear that he would agree with a paraphrasing of Thomas Jefferson that “the price of free falcons is eternal vigilance.” By carefully watching the individual components of the living world, namely species, we will gain confidence (and inspiration) that we will see positive changes, which will indicate that more efforts such as White’s are needed. Read the book.

Introducing the Dragonflies of British Columbia and the Yukon by Robert A. Cannings

Three groups of insects are particularly attractive to the general public for their beauty and visibility. Many books and field guides are written about butterflies, a few books are written about beetles, and fewer still are written about the glorious dragonflies. Dr. Robert Cannings’s book is a useful guide to the recognition and identification of Odonata from westernmost Canada. The small book is loaded with fine color photographs of many species from that area and will serve amateurs and professionals alike as a reference to this rather extensive fauna. I was particularly impressed with the color photograph of a lance-tipped darner in lateral view. This figure is used to illustrate the features of particular interest in identifying the specimens one might encounter during jaunts in the study area. A short description of habitats along with dragonflies likely to be encountered will be of value to budding, blossoming, and wilting entomologists. I appreciated the brief introduction to this fascinating part of the world. I was pleased to read that the term “dragonfly” is coming to mean any member of the order Odonata, thus giving a common name to all that can be shared in casual conversations. The bulk of the book is given to short descriptions and superb photographs of individual species. Having some personal knowledge of these wonderful organisms, I was pleased with the clarity of text and figures that could be used for effective field identification. For several of the more species-rich genera, like Aeshna, Argia, and Somatochlora, small line drawings of diagnostic features are tastefully presented without distracting from the overall beauty of the layout and the creatures themselves. Dr. Cannings is to be commended for writing such a lucid work that will be of value to folks in the study area; and, because the Okanagan Valley is largely an extension of the Basin and Range Province, it will be useful there as well.