1,720,999 research outputs found
First Record of the Exotic Ant Hypoponera ergatandria in Italy: Indoor Alate Swarms and Stinging Queens
No full textUntil recently, Hypoponera ergatandria was commonly misidentified as H. punctatissima, both of which are widespread tramp ant species. Today, H. ergatandria has been recorded in eleven European countries, while most existing H. punctatissima records are doubtful. Its geographic origins, like in the case of H. punctatissima, remain unclear. Here, we present the first record ofH. ergatandria in Italy, which also hosts H. punctatissima. We report on a large swarm of alate queens from the basement of a building in the city of Teramo, Central Italy. As reported in Florida under the name H. punctatissima, the species seems capable of producing surprisingly large alate swarms, and alate queens can become a nuisance due to their stinging ability against humans. However, Hypoponera stings are not known to pose any public health threat. Furthermore, H. ergatandria and H. punctatissima are not known to have any ecological impact and are usually confined to a very scattered distribution in Europe
La mirmecofauna della Tenuta Presidenziale di Castelporziano (Roma Italy): un esempio di indicatore ecologico di qualità ambientale
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
The role of size and shape in mating success of the slave-making ant Polyergus rufescens (Hymenoptera Formicidae): Preliminary investigation.
No full textVariations on the Author
Full text link“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
Searching for new predators of the invasive Halyomorpha halys: the role of the black garden ant Lasius niger
Full text linkIn recent years, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae, Cappaeini) has become an invasive pest in North America and Europe, where it caused extensive damage to agriculture, resulting in great economic losses. Evaluating the potential of native predators in the invaded areas, ants might represent good candidates thanks to their biology, ecology, and behavior. In Italy, H. halys proved to be the top key pest in pear orchards, where the black garden ant, Lasius niger (L.) (Hymenoptera: Formicidae, Lasiini), is the most abundant ant species. The aim of this study was to evaluate the predatory ability of L. niger on the eggs and on all the juvenile instars of H. halys under laboratory conditions. The results indicate that L. niger significantly reduces the survival of the second and third nymphal instars by 56 and 58%, respectively, but it is unable to reduce the egg hatching and the survival of the first, fourth, and fifth instars. Our preliminary results obtained in laboratory conditions suggest a possible role of the ant L. niger in controlling H. halys invasion mainly acting on the smaller and more mobile nymphal stages. The effective role of this species as potential biocontrol agents of H. halys in fruit orchards in association with other ant species as well as with other predatory insects is discussed
Unlike rolling stones: not every Myrmecina species actively rolls away from danger (Hymenoptera, Formicidae)
Full text linkActively rolling away is a very rare escape strategy in the animal kingdom, which to date has only been documented in a few arthropod and one vertebrate species. One of these arthropods is a West-Palearctic ant, Myrmecina graminicola, which has very recently been demonstrated to actively curb into a ball-like shape rolling away upon disturbance, and to selectively display this behavior only under particular circumstances. We tested whether one of the other three W-Palearctic Myrmecina species, the rare insular endemism M. sicula, exhibited the same behavioral response, using the same experimental approach used for M. graminicola. Our results showed that M. sicula reacted to moderate disturbance by either freezing its body or walking away. Only when the individual lost contact with the substratum, it could curl into a ball-like shape, yet this was significantly less refined than the one displayed by M. graminicola, as the appendages of M. sicula are not tightly kept close to its body. However, M. sicula never performed the active rolling behavior that is readily exhibited by M. graminicola. Ecological, morphological, and phylogenetic constraints may have determined the lack of a developed active rolling escape-strategy in M. sicula. Further investigations are required to assess the presence or absence of this unique behavior across Myrmecina lineages
Different nest entrance architecture by Colobopsis and Temnothorax ants colonizing oak galls
No full textGalls are neoformed structures induced on the tissues of a host plant by different organisms, mostly insects. Apart from the inducers, galls can also provide shelter to several different arthropods, referred to as secondary occupants. In certain types of galls, ants are among the prevalent secondary colonizers. This study focuses on oak galls induced by the cynipid wasp Andricus quercustozae and secondarily colonized by two ant species, Colobopsis truncata and Temnothorax italicus. We provide a first characterization of the architectural differences concerning the way they reduce the size of the exit holes excavated by the adult cynipds in order to transform them in their nest entrances. The nest entrance holes differed markedly between the two species in their size and positioning, as well as in the construction material. C. truncata built larger entrance holes with a more central position, apparently facilitating the defensive ability of the phragmotic soldiers, while the smaller nest entrance hole by T. italicus were located in a lateral position. On the other hand, only T. italicus mixed dead insect fragments in the construction material (including the defensive hastisetae of dermestid larvae), probably due to a more insectivorous diet compared to C. truncata
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