1,721,068 research outputs found
Dominance interactions in young adult foundresses of a paper wasp: a play-like behaviour?
No full textThe idea that insects play has often aroused skepticism. Nevertheless, the authors investigated the
occurrence of a playlike behavior in young individuals of a paper wasp. Polistes dominulus foundresses
hibernate in aggregations and found associative nests in the spring. In aggregations, wasps exhibit most
of the rank-dependent behaviors that they will use in the nest 6 months later. In aggregations, precocious
dominance interactions are performed with exaggerated frequencies, whereas aggression and trophallaxis
are rare. Dominance behavior in aggregations is apparently useless, but it probably allows wasps to assess
their dominance potential without any apparent reproductive competition. Surprisingly, these interactions
may be best interpreted as play because dominance behavior in aggregations shares several features with
mammalian play fighting
Cuticular hydrocarbons of Polistes dominulus as a biogeographic tool: a study of populations from the Tuscan Archipelago and surrounding areas.
No full textIn social insects, the types and proportions of epicuticular lipids
may exhibit significant diversity as a result of factors such as age, sex, caste,
rank, nest, and relatedness. It is known that these variations can be used by
social insects to acquire information regarding conspecific individuals. Recent
findings have shown that different populations of Polistes dominulus (Christ.)
have distinctly different chemical cuticular profiles, and that wasps are able
to recognize individuals of their own population. In this study, we showed that
cuticular hydrocarbon patterns of Polistes dominulus are consistent with similarities
among northern Tyrrhenian islands, as reported in previous biogeographic
studies. Indeed, our findings indicate that cuticular hydrocarbon mixtures of
P. dominulus from Capraia and Corsica are grouped together by cluster analysis,
while those from Elba and Giglio cluster with cuticular profiles of the
mainland wasps (Venturina)
Dufour’s gland possible role in the evolution of sting morphology and function in hover wasps (Hymenoptera Stenogastrinae)
No full textThe sting is the most effective defense of social Hymenoptera against vertebrate predators but in the hover wasps (subfamily Stenogastrinae) it is scarcely used. In these wasps a quite enlarged Dufour's gland and the extensive use of its secretion in the peculiar rearing of the larvae and defense determined important morphological modifications of the sting structure. Connecting anatomical and morphological data with behavioral observations we determined that in these wasps the Dufour's gland secretion is attached to the egg during oviposition but can be also channeled to the outside via the sting when it is collected by adult females for larval rearing or construction of the nest ant guards. The anatomical modifications of the sting reduced the function of the sting as a defensive weapon in hover wasps. © 2012 Elsevier Ltd
Ectal mandibular gland in Polistes dominulus (Christ) (Hymenoptera, Vespidae): Ultrastructural modifications over the secretory cycle
No full textAn ultrastructural study was carried out on the secretory activity of the ectal mandibular gland in the wasp Polistes dominulus (foundress and worker females as well as males). Secretary activity in foundresses proceeds slowly during hibernation and early spring, becoming prominent in late spring and then falling sharply during the summer. This sequential pattern of ultrastructural modifications follows a functional, annual cycle. However, by comparing the subcellular changes in the gland with colonial development, it appears that secretary activity fits in with the specie's social cycle rather than merely following the seasons. The highest levels of secretory activity correspond to the early, critical breeding phases, while activity slows down with an increase in colony protection, based on both primary (passive) and secondary (active) defenses, with the emergence of the workers. These correlations suggest that the ectal mandibular gland secretary product in P. dominulus is involved in chemical nest defense. (C) 2000 Wiley-Liss, Inc
Evidence for antiseptic behaviour towards sick adult bees in honey bee colonies. Journal of Insect Physiology
Full text linkSocial life is generally associated with an increased risk of disease transmission, but at the same time it allows behavioural defence at both the individual and collective level. Bees infected with deformed-wing virus were introduced into observation hives; through behavioural observations and chemical analysis of cuticular hydrocarbons from healthy and infected bees, we offer the first evidence that honeybee colonies can detect and remove infected adult bees, probably by recognising the cuticular hydrocarbon profiles of sick individuals. We also found that health-compromised colonies were less efficient at defending themselves against infected bees, thus facing an ever increasing risk of epidemics. This work reveals a new antiseptic behaviour that can only be interpreted as an adaptation at colony level and one which should be considered an element of the social immunity system of the beehive, re-enforcing the view of a colony as an integrated organism
Chemical nestmate recognition in a stenogastrine wasp, Liostenogaster flavolineata (Hymenoptera Vespidae)
No full textWe investigated the chemical basis of nestmate recognition in the cluster-nesting stenogastrine wasp, Liostenogaster flavolineata. We conducted both behavioural experiments and chemical analysis of the cuticular lipids. As controls, colonies were presented with dead nestmate or non-nestmate conspecific females. The importance of cuticular lipids was tested by (i) presenting nestmates and non-nestmates deprived of their cuticular lipids; (ii) presenting specimens deprived of their own cuticular lipids and then re-treated with the cuticle extracts of nestmate or alien females. We also performed bioassays to test the involvement of the Dufour's gland secretion in the recognition process. The behavioural reactions of the colonies indicate that chemical cues on the body surface are necessary for nestmate discrimination. The chemical composition of the cuticular lipids of nestmates was found to-be more similar than that of. non-nestmates, suggesting the possible involvement of these compounds in the recognition process. We suggest two hypothesis to explain the common recognition errors observed during our bioassays
A previously unreported association between a social wasp and a social passerine bird
No full textAn unreported association between the primitive social wasp Belonogaster
lateritia Gerstaecker 1857 (Hymenoptera Vespidae) and the social bird Philetarius
socius (Latham 1790) (Aves Ploceidae) is recorded. This association was observed
only on active bird nests in a savannah area of central Namibia. On 25 checked
nests, it was recorded on 5 of 5 active nests and 0 of 7 abandoned nests in savannah
vegetation, never in desert areas. The wasp uses the inferior side of the bird
nest aggregation, where tunnels open, as a substrate to fix the nest peduncle. The
social and complex nests of P. socius are interpreted as an adaptive behaviour
to reduce predation, and the presence of an aggressive associate wasp increases
the defence against predators. The advantage for the wasp, besides the use of the
substrate, could be the easiness of predation on flies attracted under the nest by
the store of bird faeces
Pre-hibernating aggregations of Polistes dominulus: an occasion to study early dominance assessment in social insects.
No full textAt a very early age several mammals establish a
first dominance hierarchy, which often persists into
adulthood. Social wasps offer an excellent opportunity to
study such a phenomenon in insects. Indeed, foundresses
of several paper wasps meet in clusters to hibernate from
September to March. In spring, wasps found new
associative nests where linear hierarchies occur. In the
first phase of hibernation, clustering Polistes dominulus
wasps show most of the social interactions occurring on the
nest 6 months later. At the emergence from diapause, some
females already show some behavioral and physiological
traits typical of dominant individuals. Here, we investigated
the significance of the interactions in the autumnal
clusters. We demonstrated that in a given pair, it is more
likely that the dominant wasp in autumn becomes the alpha
female in spring after the nest foundation phase occurred.
Moreover, we showed that dominant females in clusters
have both larger body size and ovaries. As ovarian
development mainly depends on the social context, our
findings seem to indicate that social factors affect the
tendency to dominate in aggregations. Furthermore, we
suggest that some females may reinforce their physiological
status by dominating in clusters, thus increasing the
probability to become dominant in spring
Alterazione dell’ “acceptance threshold” in api bottinatrici sperimentalmente infettate con il virus delle ali deformi (DWV)
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