Dennis Paulson

Leptobasis guanacaste is described from seasonal wetlands in dry forest in Guanacaste, Costa Rica. It is unique among the five species of the genus in thoracic color pattern and the structure of the male terminal appendages and female mesostigmal laminae and appears to be closest to L. candelaria through similarities in genital ligula, male metafemur, and female ovipositor.

ABSTRACT Herein I respond to a critique of my paper on wing positions in Zygoptera. The author of that critique suggested that most of the hypotheses presented in that paper were flawed and questioned some of the facts brought to bear on them. In addition, he presented his own ideas in support of hypotheses I had rejected. I take this opportunity to clarify my reasoning further. Although I did not elaborate sufficiently in some cases, no statement made in my paper was incorrect. My critic and I are in agreement that this is a complicated matter, and all hypotheses continue to be worth further testing.

ABSTRACT This report summarizes progress that has been made during the past five years toward the understanding of Neotropical Odonata. It also presents a list of critical species and sites, threats to Odonata conservation in the region, and priorities for further research. This region, the richest in the world for Odonata, must be a focus of intense research and conservation efforts.

Abstract Zygoptera show two perching modes, one with wings closed and one with wings open. These perching modes are distributed unequally through the suborder; most Zygoptera perch with closed wings, but species in 43 genera of eight families at least occasionally - in most cases usually - perch with open wings. Alternative hypotheses to explain this dichotomy are assessed. The dichotomy does not seem to be explicable by the Phylogenetic Inertia Hypothesis (PIH), the Wing Display Hypothesis (WDH), or the Thermoregulation Hypothesis (TH). I propose a hypothesis that the openwing position used by some zygopterans facilitates either more rapid takeoff or quicker orientation toward flying prey: the Quick Takeoff Hypothesis (QTH). That openwing species usually take flying prey furnishes support for the QTH, although many closedwing species also take flying prey. However, as most zygopterans perch with closed wings, that behavior needs explanation too, and I propose a hypothesis that perching with wings spread may make a zygopteran more conspicuous to predators and thus may be disadvantageous: the Shiny Wing Hypothesis (SWH). Larger species are less at risk of predation than smaller species, open wings in shade should be less conspicuous than in sunlight, and the majority of zygopterans with open wings are large tropical shade perchers, furnishing support for the SWH.

... m. We were surprised by the proximity of the sandpipers to the plovers, because there seemed to be many similar areas of tundra that could ... Lesser Golden-Plovers (Pluvi-alis dominica) were less likely to attack avian predators; from the five pairs in our study area, we observed ...

Abstract. The purpose of this application, under Articles 23.9.3 and 81.1 of the Code, is to conserve the widespread usage of the generic name Erythemis Hagen, 1861 for a group of common dragonflies from the New World over the simultaneously published nominal genus Lepthemis Hagen, 1861, selected to take precedence by the First Reviser action (Article 24.2), whenever these names are considered to be synonyms. This proposal seeks to achieve the least change in the nomenclature of the species currently placed in these two genera, in strict accordance with Principle 4 of the Code.

Paulson, D. R. (Department of Zoology, University of Washington, Seattle, Washington 98195) 1974. Reproductive Isolation in Damselflies. Syst. Zool. 23:40-49.-Experiments were performed in the field on males of five species and females of ten species of damselflies (Odonata: Zygoptera: Coenagrionidae) to determine the relative importance of visual and mechanical reproductive isolating mechanisms. Males of all five species did not distinguish visually their own female from heterospecific females of the same genus, but they were slightly less responsive to females of other genera, probably because of size differences. When the males attempted to mate with females of other species, they were usually prevented from doing so because their abdominal appendages were unable to secure a firm grip on the appropriate thoracic structures in the females. In only one species pair was the male able to achieve the tandem position successfully most of the time, and the reciprocal was unable to do so. Mechanical isolation is clearly very important in this group of odonates, and it is hypothesized that it will be found to be important in all odonates in which male appendages differ substantially between species while female coloration does not. [Reproductive isolation; damselflies.] Recent discussions of reproductive isolation in animals (Littlejohn, 1969; Mayr, 1970; Dobzhansky, 1970; Stebbins, 1971) emphasize that there is very little evidence for the operation in nature of the phenomenon of mechanical isolation, in which the genitalia of a male of one species fail to fit with the genitalia of a female of another species, thus preventing mating. Mayr (1963, 1970) cited a study by Webb (1947) of polygyrid snails as perhaps the only good example of interspecific mating being prevented by the structure of the genitalia. That paper is not convincing, the most positive evidence of mechanical isolation being "observations wherein the mating has been noted to be obstructed by out-of-timing malfunctioning. In one case, persistently-faster-eversion prevented a common entwistment of the penis with that of the prospective mate" (Webb, 1947:137). This apparently was an attempted mating between individuals of the same species, and Webb went on to say that he had never observed attempts at "interspecific sementransfer by any of the polygyrin species studied." In the related subfamily Triodopsinae cross-copulation between different species was observed, and in some of these species it was successful. Webb did not write that he observed individuals of different species attempting copulation but being prevented from copulating by the structure of their genitalia, and his paper is not evidence of mechanical isolation in animals. Mayr (1963) further cited two lines of evidence from a number of taxa against the existence of mechanical isolation: (1) species with different genitalia can interbreed; and (2) altering the male genitalia fails to prevent successful copulation and fertilization. Thus he concluded that "mechanical isolation plays a very minor role as an isolating mechanism in most groups of animals" (1963: 104). In fact, Mayr (1970) attempted to explain the differences among the genitalia of related species as incidental changes, the pleiotropic by-products of many changes in the genetic constitution of the species. He hypothesized that as long as any sort of apparatus could function during clasping and copulation, then variations would not be subject to selection. Dobzhansky went further in stating that the "usefulness of genitalia for distinguishing species does not necessarily mean that they are important in mechanical isolation. The reason for their usefulness is that the complexity of genitalic structures is often so great that species differences are more likely to be manifested in these structures than in

During the two decades (20012020) of the journal's existence, 346 papers on Odonata were published in Zootaxa. These papers contributed 317 new extant taxa, 26 new fossil taxa, and 106 new larval descriptions. By the end of the period, papers in Zootaxa were contributing slightly more than half of all descriptions of new extant taxa. Research was published from all over the world but predominantly from the American and Asian tropics, and authors from 42 countries contributed papers.

The status and trends of global biodiversity are often measured with a bias towards datasets limited to terrestrial vertebrates. The first global assessment of an insect order (Odonata) provides new context to the ongoing discussion of current biodiversity loss. A randomly selected sample of 1500 (26.4%) of the 5680 described dragonflies and damselflies was assessed using IUCN’s Red List criteria. Distribution maps for each species were created and species were assigned to habitat types. These data were analysed in respect to threat level for regions and habitat types. We have found that one in 10 species of dragonflies and damselflies is threatened with extinction. This threat level is among the lowest of groups that have been assessed to date, suggesting that previous estimates of extinction risk for insects might be misleading. However, Odonata only comprise a small invertebrate order, with above-average dispersal ability and relatively wide distribution ranges. For conservation ...

... Calopteryx amata Hagen—Superb Jewelwing Calopteryx amata Hagen, 1889: 244 TL: New Hampshire, Dublin, near Thorndike Pond, 1300 ft. ... Name: wounded, probably referring to blood-red wing spots in male Eng Name: canyon streams typical habitat Range: Utah and New ...

A collection of 448 Odonata specimens made on Pohnpei, Caroline Islands, Micronesia, in 2001–2002 allows a reassessment of the fauna of this small, isolated island. There are 15 species, including six species of the zygopteran genus Teinobasis, which apparently speciated in situ, an unusually great diversity for such a small island. One of these species was undescribed. A revised key to the Teinobasis of Pohnpei is included, the larvae of three species of Teinobasis are compared, and the females of T. aerides and Pacificothemis esakii are described for the first time. The three odonate species represented by adequate series, T. ariel, T.fortis, and Hemicordulia haluco, appear to increase in body size with elevation. The island still has all of its natural habitats, although native upland forests continue to decrease as more land is cleared for agriculture. All of the odonate species seem secure at this time, although T. nigrolutea appears to be less common now than in the past.

I. erratica, previously poorly known, has been found to be locally common between southwestern British Columbia and the San Francisco Bay region of California. It is an early-spring species, flying progressively later toward the north; extreme dates are 23 March and 8 August. Adults typically occur at beaver ponds but inhabit other fresh-water habitats as well. Behavior is atypical for Ischnura but rather similar to many species of Enallagma and Coenagrion. Other attributes of the species indicate it may occupy a primitive position within the genus.

Subaeschna Martin, 1908, is synonymized with Gynacantha Rambur, 1842, and its only sp., S. francesca Martin, 1909, becomes Gynacantha francesca (Martin). G. bartai sp. n. is described from 5 specimens (holotype male and allotype female; Peru, Madre de Dios, Explorer's Inn; deposited in the NMNH, Washington, DC, USA) from southern Peru. It is characterized by very small size, unmarked thorax, straight cerci, and abdomen constricted in male and unconstricted in female.

Although said to winter entirely in southern South America, Lesser Golden- Plovers (Pluvialis dominica dominica) have been recorded in eastern North America in small numbers throughout the winter. A literature search indicates that records are regular through December, most of them probably of late fall migrants, and again increase in late February, probably of early spring migrants. There are at