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Descriptions of two new species of Myrmedonota Cameron (Staphylinidae: Aleocharinae) from Mexico with comments on the genus taxonomy and behavior
No full textMathis, Kaitlyn A., Eldredge, K. Taro (2014): Descriptions of two new species of Myrmedonota Cameron (Staphylinidae: Aleocharinae) from Mexico with comments on the genus taxonomy and behavior. Zootaxa 3768 (1): 95-100, DOI: 10.11646/zootaxa.3768.1.
Myrmedonota shimmerale Mathis & Eldredge, sp. n.
No full textMyrmedonota shimmerale Mathis & Eldredge, sp. n. Type series. Holotype, male: MEXICO: Chiapas: Finca Irlanda Biological Station (15 ° 11 ′ N, 92 ° 20 ′ W) 25.ix. 2012, on sticky trap, coll. K. Mathis. Paratypes: 10, same data as holotype. Etymology. The name refers to the dull green iridescence of the integument that makes the beetle appear to shimmer in light. Diagnosis. This species can be distinguished from all other species of New World Myrmedonota by its dull iridescent green integument, small size, presence of a shallow basomedial impression on the pronotum, form of the aedeagus and spermatheca. Description. Body (Fig. 1) compact-slender and subparallel. Length with a mean of 2.09 mm (n = 5), color yellowish to black, integument overall shining with a dull green iridescence. Head, pronotum and abdominal tergites III–VII black; elytra black to light brown; abdominal tergites I–II yellowish light brown to black; mouthparts, legs yellowish to black; antennae black, segments I–III may be yellowish light brown to yellowish brown. Legs short; hind tibia 0.785 times as long as the elytral width. Macrosetae less prominent; antennal macrosetae 1.8 times the width of antenomeres. Male. Median lobe (Figs. 2–3) somewhat limuloid in parameral view; apical lobe gently curved paramerally in lateral view, pointed at apex in lateral and parameral views; copulatory piece wide, apically subulate and base with lateral paired rounded arms, annulus large and laterally wide; comb of teeth present, directed paramerally in lateral view and apical of copulatory piece. Tergite VIII apicomedially concave and margin variably serrate. Female. Spermatheca (Fig. 4) curved twice. Mildly S-shaped. Internal cone with circumventral sculptural grooves.Published as part of Mathis, Kaitlyn A. & Eldredge, K. Taro, 2014, Descriptions of two new species of Myrmedonota Cameron (Staphylinidae: Aleocharinae) from Mexico with comments on the genus taxonomy and behavior, pp. 95-100 in Zootaxa 3768 (1) on pages 97-98, DOI: 10.11646/zootaxa.3768.1.7, http://zenodo.org/record/22611
Myrmedonota xipe Mathis & Eldredge, sp. n.
No full textMyrmedonota xipe Mathis & Eldredge, sp. n. Type series. Holotype, male: MEXICO: Chiapas: Finca Irlanda Biological Station (15 ° 11 ′ N, 92 ° 20 ′ W) 25.ix. 2012, on sticky trap, coll. K. Mathis. Paratypes: 10, same data as holotype. Etymology. The name refers to Xipe Totec, the Aztec life-death-rebirth deity that was worshipped in part by flaying human sacrifices in an act symbolizing the casting off of the old and new growth. The name is a metaphor for the species role in Azteca sericeasur ant societies. The beetles prey on phorid parasitized workers whose deaths reduce phorid fly populations and benefit the colony as a whole (Mathis, in preparation). Diagnosis. This species can be distinguished from all other species of New World Myrmedonota by color pattern, bifid apex of the median lobe, form of the median lobe and copulatory piece. Description. Body (Fig. 5) slender and subparallel. Length with a mean of 3.2 mm (n = 5), color yellowish to black, integument overall dull. Head and abdominal tergites VI–VII dark brown to black; pronotum, elytra, and abdominal tergite V yellow to dark brown; abdominal tergites I–IV yellowish to light brown; mouthparts and legs yellowish; antennae dark brown, segments I–III and apex of segment XI may be yellowish. Legs long; hind tibia 0.78 times as long as the elytral width. Macrosetae prominent; antennal macrosetae 2.47 times the width of the antenomere. Male. Median lobe (Figs. 6–7) somewhat limuloid in parameral view, apex slightly bifid; apical lobe gently curved paramerally in lateral view, generally pointed at apex in lateral and parameral views; longitudinal bands large and conspicuous; copulatory piece overall narrow, apex slender and attenuated, base with lateral paired blunt arms slightly constricted at midpoint, annulus small and longitudinally elongate; comb of teeth present, directed paramerally in lateral view and apical of copulatory piece. Tergite VIII apicomedially concave and margin variably serrate. Female. Spermatheca (Fig. 8) bent submedially at near-right angle. Internal cone with circumventral sculptural grooves.Published as part of Mathis, Kaitlyn A. & Eldredge, K. Taro, 2014, Descriptions of two new species of Myrmedonota Cameron (Staphylinidae: Aleocharinae) from Mexico with comments on the genus taxonomy and behavior, pp. 95-100 in Zootaxa 3768 (1) on pages 98-99, DOI: 10.11646/zootaxa.3768.1.7, http://zenodo.org/record/22611
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Myrmedonota Cameron 1920
No full textGenus Myrmedonota Cameron, 1920 Diagnosis. The following character states in combination can diagnose Myrmedonota from other New World genera of Aleocharinae: (1) tarsal formula 4-5 - 5; (2) mesocoxae widely separated; (3) metaventral process much longer than mesoventral process, which extends little between the mesocoxae; (4) galea length greater than 7 times width at base, maxillae overall appearing extremely slender and elongate; (5) neck absent; (6) occipital suture complete to hypostoma; (7) pronotum with complete marginal line; (8) paramerite vellum much larger than condylite vellum; (9) paramerite vellum obscuring condylite vellum from outer view, condylite vellum small and fan-shaped; (9) apical lobe of paramere free and articulating with paramerite; (10) glossa bifid; (11) labial palpomere II and III subequal in length. Comments on taxonomy. Myrmedonota taxonomy is quite chaotic. Elven et al. (2010) demonstrated that Myrmedonota and other New World genera formerly classified under Lomechusini are in fact a lineage within Athetini that has converged on similar morphologies (Elven et al. 2010). Both Lomechusini and these pseudolomechusines are often symbiotic with ants and termites, one potential explanation for convergence may be adaptively rooted in symbiont ecology. Since Elven et al. (2010), more formalized morphological characters that diagnose Lomechusini from pseudolomechusines are becoming apparent (Eldredge personal observation). It is turning out that most New World taxa fall under the currently outdated diagnostic umbrella of Lomechusini are pseudo-lomechusines, and belong to Athetini. This is in contrast to Lomechusini, which are predominantly distributed in the Old World. Therefore, superficially there appears to be a New World-Old World divide in distribution between pseudo-lomechusines and Lomechusini respectively. This is interesting in that it implies there have been two independent evolutionary histories with the lomechusine-morphotype; both have diversified in the context of social insect symbiosis and demonstrate potential for a comparative study of symbiosis. Even with this enlightened perspective of a pseudo-lomechusine lineage, Myrmedonota as currently understood is plesiomorphic in overall body morphology, and many genera may in fact be lineages that have derived from Myrmedonota, rendering it paraphyletic. For example, the genus Termitognathus Borgmier, 1959 may be one such lineage, only diagnosable by morphologies derived from the pressures of living with termites. To attest to the difficulties with distinguishing Myrmedonota from some other pseudo-lomechusine genera, Pace (1997, 2008a, 2008 b, 2009) in a series of publications may have in fact described species of Myrmedonota under Apalonia Casey, 1906 (Eldredge 2012). Habitus and genitalic figures that accompany Pace’s descriptions support this hypothesis. In order to address issues concerning Myrmedonota taxonomy, the new species described below have been compared with Pace’s (1997, 2008a, 2008 b, 2009) descriptions. We bring up these issues on Myrmedonota taxonomy, even though much of the above is still speculative, because we think that Myrmedonota may be phylogenetically important. More apomorphic symbiont lineages may nest within Myrmedonota as we currently diagnose it, making the genus important in understanding the evolution of social insect symbiosis among pseudo-lomechusines. Additionally, this has implications if evolution of social insect symbiosis is to be studied comparatively between Lomechusini and pseudo-lomechusines. We suggest that new genera of pseudo-lomechusines be erected with caution, and urge the phylogeny reconstruction of this diverse clade. Comments on behavior. Observations of Myrmedonota behavior have been accumulating for some time, although most are unpublished. From these, two interesting tendencies have come to light: (1) Myrmedonota swarm to ant colonies, especially during periods of colony agitation; (2) Myrmedonota mate by swarming, frequently in the presence of ants. Myrmedonota are predators, and as ant symbionts either predators of ants (Eldredge personal observation, Mathis in preparation) or scavengers (Kistner 2003). In Costa Rica, Eldredge has observed a Myrmedonota species fly into the midst of an agitated Pheidole Westwood, 1839 colony during nest excavation. Mathis (in preparation) has made detailed observations of aggregation and predation behavior of the two new species described below, but these will be presented subsequently. Mating swarms of M. lewisi Maruyama et al. 2008 have been observed to occur on open ground with no apparent landmark (Eldredge personal observation, http://youtu.be/S 3 cdOavPZmc). Adults would fly above ground and periodically land, at which time they begin a searching behavior until the opposite sex is found. Upon locating a mate, a circular, almost ritualistic chase begins, followed by brief copulation. A white sheet placed on the ground did not elicit concentrated swarming around the sheet, but did allow easier observation of matings. Eldredge also observed mating swarms of a Myrmedonota species in Costa Rica, concentrated around the foraging column of an Eciton Latreille, 1804 species. The two new species described below have been observed mating in the presence of agitated Azteca sericeasur often while Pseudacteon phorid fly attacks took place (Mathis personal observation, http://youtu.be/ 1 IwRT 8 EAp0Y). Adults appear to be attracted to a chemical compound present within the alarm pheromone of Azteca sericeasur (Mathis, in preparation). When the adults arrive to the location and find a mate, a chase begins, often resulting in a lengthy copulation.Published as part of Mathis, Kaitlyn A. & Eldredge, K. Taro, 2014, Descriptions of two new species of Myrmedonota Cameron (Staphylinidae: Aleocharinae) from Mexico with comments on the genus taxonomy and behavior, pp. 95-100 in Zootaxa 3768 (1) on pages 96-97, DOI: 10.11646/zootaxa.3768.1.7, http://zenodo.org/record/22611
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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