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... more
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.
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Most studies of insect flight deal primarily with hovering or with forward flight at constant, moderate speed. This paper reports investigations of flight characteristics that are especially relevant to the performance of dragonflies at... more
Most studies of insect flight deal primarily with hovering or with forward flight at constant, moderate speed. This paper reports investigations of flight characteristics that are especially relevant to the performance of dragonflies at high and/or changing velocity. Dragonflies were filmed in free flight in the field to determine velocity and acceleration. The power required for repeated acceleration is shown to be large, in some circumstances, relative to the estimated maximum available power and probable top power requirements for steady flight. Distributions of velocity and acceleration, and concomitant power requirements, differ markedly among species, however. In addition, parasite drag was measured in winds of 2–7ms−1 and drag coefficients determined to be about 0.40 at Reynolds number greater than 104. This result implies substantially lower power requirements at high speeds, compared to previous estimates. Other aspects of power output, including the probable magnitude of i...
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Mass-specific oxygen consumption of euglossine bees during free hove ringflight is inversely related to body mass, varying from 66 mlO2 g−1 h−1 in a 1.0 -g bee to 154 mlO2 g−1 h−1 in a 0.10 -g bee. Individuals of Eulaema and Eufreisea... more
Mass-specific oxygen consumption of euglossine bees during free hove ringflight is inversely related to body mass, varying from 66 mlO2 g−1 h−1 in a 1.0 -g bee to 154 mlO2 g−1 h−1 in a 0.10 -g bee. Individuals of Eulaema and Eufreisea spp. have smaller wings and higher wing stroke frequency and energy metabolism at any given mass than bees of Euglossa spp. or Exaeretefrontalis. Calculated aero dynamic power requirements represent only a small fraction of the energy metabolism, and apparent flight efficiency aero dynamic power (= induced + profile power)/power input decreases as sizedeclines. If efficiency of flight muscle = 0.2, the mechanical power output of hovering bees varies inversely with body mass from about 480 to 1130 W kg−1 of muscle. These values are 1.9 to 4.5 times greater than previous predictions of maximum mechanical power output (Weis-Fogh & Alexander, 1977; see also Ellington, 1984c). Mass-specific energy expenditure per wing stroke is independent of body mass and ...
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Intrafamilial relationships among clubtail dragonflies (Gomphidae) have been the subject of many morphological studies, but have not yet been systematically evaluated using molecular data. Here we present the first molecular phylogeny of... more
Intrafamilial relationships among clubtail dragonflies (Gomphidae) have been the subject of many morphological studies, but have not yet been systematically evaluated using molecular data. Here we present the first molecular phylogeny of Gomphidae. We include six of the eight subfamilies previously suggested to be valid, and evaluate generic relationships within them. We have included examples of all genera reported from the Nearctic except . This sample includes all North American species of , which has allowed us to explore intrageneric relationships in that genus. Our particular focus is on the closest relatives of the genus , especially those North American species groups that have been commonly treated as subgenera of . The complex is split into additional genera, supported by molecular and morphological evidence: and are here considered to be valid genera. The genus , in our restricted sense, does not occur in the western hemisphere; in addition, is transferred to .
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... male from Brazil, identified as M. t. tessellata by ND dos Santos, shows it to be extremely similar to Central America forms except ... on flexor surface, triangular in outline with tips directed distally, followed by 3-5 much longer,... more
... male from Brazil, identified as M. t. tessellata by ND dos Santos, shows it to be extremely similar to Central America forms except ... on flexor surface, triangular in outline with tips directed distally, followed by 3-5 much longer, slender spurs; abdomen and hindwings shorter than 20 ...
Research Interests: Zoology and Odonatology
... Michael L. May Department of Entomology, New Jersey Agricultural Experiment Station,Rutgers University, New Brunswick, NJ 08901-8524, USA ... In this respect they are similar to another late-season species, S. danae (Michiels &... more
... Michael L. May Department of Entomology, New Jersey Agricultural Experiment Station,Rutgers University, New Brunswick, NJ 08901-8524, USA ... In this respect they are similar to another late-season species, S. danae (Michiels & Dhondt, 1989). ...
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Research Interests: Zoology and Odonatology
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A small inconspicuous spine, first detected at the base of the distal-most seta on each labial palpus of early stadia of two species of Enallagma, is reported to occur in final-stadium (F-0) larvae of Palaearctic and Nearctic E.... more
A small inconspicuous spine, first detected at the base of the distal-most seta on each labial palpus of early stadia of two species of Enallagma, is reported to occur in final-stadium (F-0) larvae of Palaearctic and Nearctic E. cyathigerum, in F-0 of 31 other Nearctic species of Enallagma and in F-0 of three other coenagrionid genera among 11 inspected for this character. The spine is absent from F-0 of eight other coenagrionid genera, including Coenagrion and Ischnura. It is also lacking from F-0 of the two species of Afrotropical Enallagma that we examined, a discovery that suggests the latter may not be closely related to Nearctic and Palaearctic species. In European populations such a spine occurs in the first few stadia of certain Coenagrion species but persists to F-0 only in E. cyathigerum. We re-emphasize the potential value of this spine as a means of distinguishing at least the last three stadia of E. cyathigerum from those of other coenagrionid genera in Europe, and very probably from Coenagrion and Ischnura everywhere.
Research Interests: Zoology and Odonatology
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Although libelluloid dragonflies are diverse, numerous, and commonly observed and studied, their phylogenetic history is uncertain. Over 150 years of taxonomic study of Libelluloidea Rambur, 1842, beginning with Hagen (1840), [Rambur,... more
Although libelluloid dragonflies are diverse, numerous, and commonly observed and studied, their phylogenetic history is uncertain. Over 150 years of taxonomic study of Libelluloidea Rambur, 1842, beginning with Hagen (1840), [Rambur, M.P., 1842. Neuropteres. Histoire naturelle des Insectes, Paris, pp. 534; Hagen, H., 1840. Synonymia Libellularum Europaearum. Dissertation inaugularis quam consensu et auctoritate gratiosi medicorum ordinis in academia albertina ad summos in medicina et chirurgia honores.] and Selys (1850), [de Selys Longchamps, E., 1850. Revue des Odonates ou Libellules d'Europe [avec la collaboration de H.A. Hagen]. Muquardt, Bruxelles; Leipzig, 1-408.], has failed to produce a consensus about family and subfamily relationships. The present study provides a well-substantiated phylogeny of the Libelluloidea generated from gene fragments of two independent genes, the 16S and 28S ribosomal RNA (rRNA), and using models that take into account non-independence of correlated rRNA sites. Ninety-three ingroup taxa and six outgroup taxa were amplified for the 28S fragment; 78 ingroup taxa and five outgroup taxa were amplified for the 16S fragment. Bayesian, likelihood and parsimony analyses of the combined data produce well-resolved phylogenetic hypotheses and several previously suggested monophyletic groups were supported by each analysis. Macromiinae, Corduliidae s. s., and Libellulidae are each monophyletic. The corduliid (s.l.) subfamilies Synthemistinae, Gomphomacromiinae, and Idionychinae form a monophyletic group, separate from the Corduliinae. Libellulidae comprises three previously accepted subfamilies (Urothemistinae, a very restricted Tetrathemistinae, and a modified Libellulinae) and five additional consistently recovered groups. None of the other previously proposed subfamilies are supported. Bayesian analyses run with an additional 71 sequences obtained from GenBank did not alter our conclusions. The evolution of adult and larval morphological characters is discussed here to suggest areas for future focus. This study shows the inherent problems in using poorly defined and sometimes inaccurately scored characters, basing groups on symplesiomorphies, and failure to recognize the widespread effects of character correlation and convergence, especially in aspects of wing venation.
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ABSTRACT AimTo explore the phylogenetics and historical biogeography of the dragonfly family Petaluridae (known as ‘petaltails’), a relict dragonfly group with unique habitat and life history attributes.LocationAustralia, New Zealand,... more
ABSTRACT AimTo explore the phylogenetics and historical biogeography of the dragonfly family Petaluridae (known as ‘petaltails’), a relict dragonfly group with unique habitat and life history attributes.LocationAustralia, New Zealand, Japan, Chile and North America.Methods Using five mitochondrial and three nuclear gene fragments we recovered garli-part maximum likelihood and Bayesian phylogenetic hypotheses for 10 of the 11 extant petaltail species. Biogeographical patterns were analysed using Lagrange and interpreted through beast relaxed clock dating analysis.ResultsPetaluridae is monophyletic with an origin in the mid-Jurassic, c. 157 Ma. The family consists of two major clades: one with a Laurasian distribution containing the genera Tachopteryx and Tanypteryx, and another containing the genera Petalura, Phenes and Uropetala, distributed in Gondwanan remnants. Based on our beast molecular clock, these two clades separated c. 146 Ma. Species ages in Petaluridae range from c. 100 to c. 30 million years, with the majority of the species persisting for 70–75 million years. Analysis with Lagrange points to an origin for the family associated with New Zealand, with subsequent dispersal to other Gondwanan remnants (Australia and Chile) as well as Laurasia (eastern and western North America) and subsequent dispersal from western North America to Japan.Main conclusionsThe extant species of Petaluridae are extremely old, with most species persisting as independent lineages since the Jurassic. Our results suggest that New Zealand was close to the origin point in the Jurassic; one possibility is that Antarctica was at the centre of the petalurid distribution, based on Permian fossil evidence. Such long persistence for species is surprising, especially considering the specialized habitat required by petalurid larvae; unlike the majority of modern dragonflies, which spend their larval stage in ponds or streams, petaltails live in fen habitats. Petaltails also take multiple years to develop from egg to adult, another trait uncommon in modern dragonflies. Specialization in a species is normally associated with higher extinction rates; the petaltails appear to be an exception to this rule.
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Page 1. Journal of Insect Behavior, Vol. 10, No. 5, 1997 Foraging Behavior of Pachydiplax longipennis (Odonata: Libellulidae) Joel M. Baird 1'2 and Michael L. May 1'3 Accepted February 10, 1997; revised April 7, 1997 Food ...
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1.Wingstroke frequency during pre-flight warm-up, fixed flight, and self-supported flight on a tether was measured at several body temperatures (Tb) in anisopterous dragonflies.2.Frequency increases as body size (mass or wing length)... more
1.Wingstroke frequency during pre-flight warm-up, fixed flight, and self-supported flight on a tether was measured at several body temperatures (Tb) in anisopterous dragonflies.2.Frequency increases as body size (mass or wing length) decreases and asTb increases. The change in frequency for a given change in size is greater during flight than warm-up at any givenTb, while the rate of increase with
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The damselfly genus Enallagma originated in the Nearctic, and two Nearctic lineages recently underwent radiations partly associated with multiple independent habitat shifts from lakes dominated by fish predators into lakes dominated by... more
The damselfly genus Enallagma originated in the Nearctic, and two Nearctic lineages recently underwent radiations partly associated with multiple independent habitat shifts from lakes dominated by fish predators into lakes dominated by dragonfly predators. A previous molecular study of four Palearctic morphospecies and all representative Nearctic species identified the presence of two cryptic species sets, with each set having Palearctic and Nearctic representatives. However, the cryptic species within each set are not sibling species. Here, we present quantitative data on ecologically important larval morphologies and behaviors involved in predator avoidance and on adult male morphological structures involved in mate recognition to quantify the phenotypic relationships among these cryptic species sets. For the adult stage, our data indicate strong parallel evolution of the structures involved in specific mate recognition-the male cerci. For the larval stage, morphometric analyses show that the Palearctic species evolved a nearly identical morphology to the sibling-clade members in the Nearctic that live in waters where dragonflies are the top predators. This implicates the importance of dragonfly predation in the history of the Palearctic clade. Behavioral analyses suggest population differentiation in response to the actual predator environment in the Palearctic clade, consistent with the species differentiation seen in the Nearctic. Our results suggest parallel evolution of adult traits that influence specific mate choice and larval traits that influence ecological performance underlie the striking similarity of Enallagma species across continents. This concurrent parallel evolution in both stages of a complex life cycle, especially when both stages do not share the same selective environment, may be a very unusual mechanism generating cryptic species.
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... pp 79-114. In PW Colgan (ed), Quantitative Ethology. John Wiley and Sons, New York. Johnson, FA, 1915. Asparagus-beetle egg parasite. J. AgrlC. Res. 4: 303-313. ... Neth. J. Zool. 30: 254-277.Lashomb, JH, JD Krainacker, RK Jansson, YS... more
... pp 79-114. In PW Colgan (ed), Quantitative Ethology. John Wiley and Sons, New York. Johnson, FA, 1915. Asparagus-beetle egg parasite. J. AgrlC. Res. 4: 303-313. ... Neth. J. Zool. 30: 254-277.Lashomb, JH, JD Krainacker, RK Jansson, YS Ng & R. Chianese, 1987. ...
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Every year billions of butterflies, dragonflies, moths and other insects migrate across continents, and considerable progress has been made in understanding population-level migratory phenomena. However, little is known about destinations... more
Every year billions of butterflies, dragonflies, moths and other insects migrate across continents, and considerable progress has been made in understanding population-level migratory phenomena. However, little is known about destinations and strategies of individual insects. We attached miniaturized radio transmitters (ca300 mg) to the thoraxes of 14 individual dragonflies (common green darners,Anax junius) and followed them during their autumn migration for up to 12 days, using receiver-equipped Cessna airplanes and ground teams. Green darners exhibited distinct stopover and migration days. On average, they migrated every 2.9±0.3 days, and their average net advance was 58±11 km in 6.1±0.9 days (11.9±2.8 km d−1) in a generally southward direction (186±52°). They migrated exclusively during the daytime, when wind speeds were less than 25 km h−1, regardless of wind direction, but only after two nights of successively lower temperatures (decrease of 2.1±0.6 °C in minimum temperature)....
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Page 1. Ann. Rev. Entomol. 1979. 24:313-49 Copyright @ 1979 by Annual Reviews Inc. All rights reserved INSECT THERMOREGULATION Michael L. May Department of Physiology and Biophysics, University of Illinois, Urbana, Illinois 61301 ...
Research Interests: Zoology and Entomology
... KENNETH L. SOLTESZ Westchester County Department of Parks, Recreation and Conservation, Mt. ... Some previous authors have speculated that the migratory terminus might be along the Gulf Coast (Bagg, 1958; Leahy, 1983) or even Central... more
... KENNETH L. SOLTESZ Westchester County Department of Parks, Recreation and Conservation, Mt. ... Some previous authors have speculated that the migratory terminus might be along the Gulf Coast (Bagg, 1958; Leahy, 1983) or even Central America (Boomsma and Dunkle ...
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Odonata (dragonflies and damselflies) are well-known but often poorly understood insects. Their phylogeny and classification have proved difficult to understand but, through use of modern morphological and molecular techniques, is... more
Odonata (dragonflies and damselflies) are well-known but often poorly understood insects. Their phylogeny and classification have proved difficult to understand but, through use of modern morphological and molecular techniques, is becoming better understood and is discussed here. Although not considered to be of high economic importance, they do provide esthetic/spiritual benefits to humans, and may have some impact as predators of disease vectors and agricultural pests. In addition, their larvae are very important as intermediate or top predators in many aquatic ecosystems. More recently, they have been the objects of study that have yielded new information on the mechanics and control of insect flight.
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Odonata (dragonflies and damselflies) are well-known but often poorly understood insects. Their phylogeny and classification have proved difficult to understand but, through use of modern morphological and molecular techniques, is... more
Odonata (dragonflies and damselflies) are well-known but often poorly understood insects. Their phylogeny and classification have proved difficult to understand but, through use of modern morphological and molecular techniques, is becoming better understood and is discussed here. Although not considered to be of high economic importance, they do provide esthetic/spiritual benefits to humans, and may have some impact as predators of disease vectors and agricultural pests. In addition, their larvae are very important as intermediate or top predators in many aquatic ecosystems. More recently, they have been the objects of study that have yielded new information on the mechanics and control of insect flight.