Lasius (Chthonolasius) nitidigaster Seifert, 1996 - a new ant species (Hymenoptera: Formicidae) for the Hungarian fauna

Lasius (Chthonolasius) nitidigaster Seifert, 1996, a temporary social parasite, is recorded as new for Hungarian myrmecofauna. Its main diagnostic characters, distribution and biology are briefly discussed

THE EFFECT OF LABORATORY COLONY CONDITION ON THE TROPHALLACTIC INTERACTIONS OF CAMPONOTUS VAGUS (HYMENOPTERA: FORMICIDAE)

In this study, our aim was to give a detailed evaluation of the trophallactic interactions among foragers of Camponotus vagus in outside-nest situation, and to find out which properties of trophallaxis may have a role in the information-flow among workers about current nutritional state of the colony. Measured parameters were the number and frequency of trophallactic interactions, the duration of trophallaxes, the frequency of different duration interactions, and the number and size-class of workers participating in trophallactic events outside the nest. Experiments were conducted both with starved and satiated colonies to examine the effect of feeding condition. We demonstrated that the dynamics of trophallaxis is a stable parameter; it was independent from the starvation level. Similarly,the number of partners and the size class distribution of the different sized worker pairs did not differ between the two colony states. Starvation level influenced both the frequency and mean duration of trophallactic interactions. The frequency-distribution of the duration of trophallactic events showed an exponential trend, i.e., the short term interactions were more frequent than the prolonged ones in both colony states. However, the rate of these two distinguished types of trophallaxis was different in the case of the two colony conditions. Different rates of the short term and prolonged interactions may provide information about the current nutritional requirements of the colony, enhancing the speed and efficiency of colony responses to feeding stress. Frequent short term trophallaxis may not only contribute to a high level of cooperation during retrieval of food among foragers, but also maintain the integration of colony members even outside their nest

Comparison of foraging tool use in two species of myrmicine ants (Hymenoptera: Formicidae)

Many ant species are known to exhibit foraging tool use, during which ants place various debris items (e.g., pieces of soil, leaves, pine needles, etc.) into liquid food, and then they carry the food-soaked tools back to the nest. In the present study, we compared the tool-using behavior in captive colonies of two closely related myrmicine ants with different feeding preferences: Aphaenogaster subterranea, an omnivorous species, and Messor structor, a mainly granivorous seed-harvester species. We supplied foraging ants with honey-water baits and six types of objects they could use as tools: sand grains, small soil grains, large soil grains, pine needles, leaves, and sponges. We found that the workers of A. subterranea both dropped more tools into honey-water baits and retrieved more of these tools than the workers of M. structor. While A. subterranea preferred smaller tools over larger ones, tool preferences for M. structor did not differ significantly from random. In addition, tool dropping was significantly faster in A. subterranea, and both the dropping and retrieving of tools began significantly earlier than in M. structor. For Aphaenogaster species that regularly utilize and compete for liquid food sources, the ability to efficiently transport liquid food via tools may be more important than it is for seed-harvester ants. Dropping tools into liquids, however, may still be useful for seed-harvester species as a means to supplement diet with liquid food during periods of seed shortage and also to serve as a means of getting rid of unwanted liquids close to the nest

CLOSE NESTING ASSOCIATION OF TWO ANT SPECIES IN ARTIFICIAL SHELTERS: RESULTS FROM A LONG-TERM EXPERIMENT

Close nesting (real or quasi plesiobiosis) is the simplest form of spatial associations of heterospecific ant colonies that share the same microhabitat, but remain separate as individual units. We studied the tendency to close nesting between two ant species, Lasius psammophilus and Plagiolepis taurica, under slate plates used as artificial nesting sites during a 34 years long study period. 2410 nest records of 11 ant species were made under the plates, and a total of 181 close nesting associations were observed, most of which between L. psammophilus and P. taurica. The hypothesis of the weak antagonism between the two species was supported by (1) the rate of nesting associations, which was lower than expected from random probabilities; (2) the maximum of the index of avoidance, at intermediate densities; (3) the negative relationship between the unoccupied nesting shelters and the frequency of close nesting; (4) the tendency of individual and group level avoidance and (5) the low rate of interspecific aggression. The benefit of choosing favorable nesting sites and the risk of interspecific competition are in trade-off relation and the attractiveness of nesting shelters is the stronger constraint; therefore it can be regarded as the primary driver of the formation of spatial associations between the colonies of the two studied species

INDAGINE EMPIRICA SUL SISTEMA DELLA GIURIA IN UNGHERIA

Empirijskim istraživanjem autori su tražili odgovor na pitanje koje se često nameće kod istraživanja sudova mješovitoga sastava, tj. kolika je uloga porote koja sudjeluje u sudskim postupcima i to ponajprije na temelju ocjena sudaca porotnika i profesionalnih sudaca. Pretpostavka je na temelju načelne karakteristike statusa, bila ta, da ova posebna skupina unatoč zakonskim odredbama koje im jamče jednaka prava, ima takve unutarnje hijerarhijske odnose koji sprječavaju znatniji udio porotnog sustava. To su i potvrdila slična empirijska istraživanja mješovitih sudskih sustava. Istodobno je pretpostavljeno i da u odnosu na Kulcsárova istraživanja provedena još u vrijeme jednopartijskoga sustava šezdesetih godina 20. stoljeća porotni sustav demokratskoga društva rezultira većim sudjelovanjem, čak i onda ako se od tada nije dogodila nikakva bitna izmjena pravnih propisa. U provedenom istraživanju na temelju mišljenja porotnika i sudaca, autori rada pokušali su izvršiti tipizaciju stručnih sudaca temeljem njihova odnosa prema porotnicima koji nemaju stručna pravna znanja.This research was based on lay and professional judicial assessment and aimed at answering the question of what degree and nature of lay participation in Hungary can be seen in court proceedings, a question that is already present in research into mixed tribunals. Addressed and supported by similar empirical research into mixed tribunal systems, the status characteristics theory has led the authors to the assume that, despite statutory provisions ensuring equal rights, this specific problem-solving group is characterized by such an internal hierarchical relationship that discourages increased lay participation. However, it has also been assumed that, compared to the 1960 research in Hungary, led by Kálmán Kulcsár, the lay judge system of a democratic society allows greater participation even if no relevant changes in legislation has since taken place.Während dieser empirischen Forschung versuchte man, die Charakteristiken der an Gerichtsverfahren teilnehmenden ehrenamtlichen Richter festzustellen, vor allem aufgrund der Ansichten von ehrenamtlichen Richtern und Berufsrichtern. Man ging von der Voraussetzung aus, dass aufgrund des Status von ehrenamtlichen Richtern, diese Gruppe trotz der Gesetzesbestimmungen, die ihnen die gleichen Rechte gewährleisten, keinen entscheidenden Einfluss im Gerichtsverfahren wegen inneren hierarchischen Beziehungen hat. Dies wurde auch durch ähnliche Forschungen über gemischte Gerichtssysteme bestätigt. Gleichzeitig ging man von der Voraussetzung aus, dass im Vergleich zu der von Kulcsár zur Zeit des Einparteisystems in den 1960er durchgeführten Forschung, die ehrenamtlichen Richter mit einem größeren Stimmrecht in der demokratischen Gesellschaft am Prozess teilnehmen, obwohl es seit dieser Zeit keine wesentlichen Änderungen der Gesetzesvorschriften gab. Mithilfe der durch die Forschung erhaltenen Ansichten von ehrenamtlichen Richtern und Berufsrichtern versuchte man, die Typisierung von Berufsrichtern aufgrund ihrer Beziehungen zu den ehrenamtlichen Richtern festzustellen.Nel corso dell’indagine empirica abbiamo cercato di rispodere all’interrogativo che frequentemente si presenta nelle ricerche aventi ad oggetto le corti a composizione mista e cioè quale sia il peso ed il carattere della giuria che prende parte ai procedmenti giudiziali e ciò, in primo luogo, valutando il parere dei giurati e dei giudici togati. La nostra idea è che in ragione dell’ordine gerarchico di cui gode questa particolare categoria all’interno del sistema, sia difficile che i giurati rivestano un ruolo rilevante nel processo. Un tanto è stato del resto confermato da indagini empiriche simili riguardanti i sistemi a corti miste. Al contempo siamo giunti anche alla conclusione che rispetto alle ricerche condotte nelle indagini di Kulcsárov pubblicate ancora ai tempi del sistema monopartitico degli anni ’60 del secolo scorso, il sistema della giuria nella società democratica risulta maggiormente coinvolto, anche se da allora non s’è verificata alcuna riforma normativa rilevante in tale senso. In base all’opinione dei giurati e dei giudici contattati durante la ricerca, abbiamo cercato di qualificare i giudici in base al loro rapporto verso i giurati che non dispongono di preparazione giuridica professionale

Tool selection during foraging in two species of funnel ants

This work was supported by European Commission (FP7-MC-ERG-2009-256524 to PdE).Tool use by non-human animals has received much research attention in the last couple of decades. Nonetheless, research has focused mostly on vertebrates, particularly primates and corvids, even though tool use has also been documented in insects. One of the best documented examples involves ants using debris (e.g., sand grains, mud, leaf fragments) to collect and transport liquid food to their nest. However, little is known about the factors that determine the selection of materials to be used as tool. We investigated tool selection in two species of Aphaenogaster ants by giving them the choice between different kinds of potential tools (natural and artificial objects). Ant workers showed a clear preference for certain materials to be used as tool objects. Tool selection was also shaped by familiarity with the material as ants developed a preference for artificial tools with a good soaking capacity that cannot be found in their natural environment. Our results indicate that ants of this genus evolved unique foraging strategies and show plasticity in their behaviour.PostprintPeer reviewe

Road verges are important secondary habitats for grassland arthropods

Semi-natural linear landscape elements such as road verges, hedgerows and feld margins are important in maintaining the connectivity between habitat fragments of highly modifed landscapes. Preservation of habitat specialist fauna requires conservation of the remaining natural habitat patches and connectivity of fragments. Our study focuses on the spider, ant and true bug fauna and functional diversity (FD) of fragmented forest steppe patches, moderately grazed pastures and road verges embedded in a matrix of forest plantations in Hungary, Central Europe. We established total 30 sampling sites, 10 in each, the grassland component of forest-steppes (F), pastures (P) and road verges (R) near pine forests. We collected arthropods with pitfall and sweep-net techniques. We calculated FD and species composition of arthropods using linear mixed models. We observed higher species richness in road verges for spiders and ants. We also found higher FD values for spiders and diferent trait composition for all taxa in road verges when compared with forest steppes and pastures. Species composition suggests that road verges do not serve as habitat for several forest-steppe and grassland species, in spite of the fact that numerous specialist species were found in the road verges. We show that forest steppes have higher species richness of spiders than pastures, and there are diferences in species assemblage composition of the two habitat types for all taxa. Our results indicate that road verges should be considered as an important refuge for grassland specialist arthropods, as road verges provide secondary linear habitats for many arthropod species, and we would suggest the maintenance of these grassy strips in order to preserve arthropod biodiversity