Táplálékforrás, szignál, fertőzésgóc – tetemek szerepe egyes hangyafajoknál (Hymenoptera: Formicidae).

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Social life, besides its advantages involves major negative effects, since the intensive contacts among individuals can contribute to the fast spread of pathogens. Further on, social activities and lifestyle can lead to the accumulation of waste materials in high amounts, among which corpses are the most important components. The accumulation of wastes inside a nest can promote the establishment of pathogen microorganisms and fungi, therefore waste management, although essential for the colony's survival, represents risk for the performing workers due to the increased probability of getting infected. In order to counterbalance these negative effects, many social defensive mechanisms have evolved, from which the most effective one is the disposal of corpses on waste piles, i.e. the formation of cemeteries. The corpses can also be used as food source mainly by ant species. The consumption of insect remnants, including those of other ant species, is a widespread phenomenon among ants. Corpse cannibalism is mentioned only in a few works, but it seems that the corpses that appear inside the nest or during a battle can be consumed as food. Some recent researches also highlighted the use of corpses during interspecific conflicts; the appearance of corpses can have negative effects on the behavior of the attacked colony. This behavior let us hypothesize that ants are able to recognize the corpses of different species, and react appropriately. Thus, corpses of different origin may have important signal properties. Aims In our study, we investigated (1) the response of different Formica species and that of the slave-maker Polyergus rufescens towards corpses of different rival and non-rival ant species. Besides examining the reactions towards corpses of different origin, we also analyzed the differences in the reaction towards nestmate corpses in various situations. We tested (2) the use of these corpses as sources of potential food and (3) infestations. Furthermore, we analyzed (4) the division of labor during waste management at different levels. Materials and methods In order to answer our questions, we performed investigations under field and laboratory conditions. Before the start of our work, we placed 10 freeze-killed corpses in front of the main entrances and inside the search arenas, respectively, and we observed the behavioral reactions of resident workers towards the corpses of different rival species, the number of nestmate workers around them, and the transport rate and direction of the different corpses. We used several kinds of corpses, namely corpses of nestmates (F. cinerea, F. sanguinea, P. rufescens and F. polyctena) as control, non-nestmates, submissive F. fusca and in some cases F. rufibarbis, slave-makers and their slaves, and territorial wood-ants (F. polyctena, F. pratensis and F. truncorum). In addition, we compared the reactions of the two slave-maker species (facultative F. sanguinea and obligate Polyergus rufescens) towards each other, their slaves, and corpses of potential slave species under laboratory conditions. The role of corpses as food sources was tested in the case of the nestmate corpses of F. polyctena and the corpses of D. melanogaster. The reactions to these corpses were also tested after submerging them in pure oleic acid, as a response to artificial corpse smell. The amount of nestmate corpses used as food sources were further investigated with the help of painted corpses in the case of starved and satiated colonies, and older nestmates and rival C. vagus corpses. The experimental corpses were measured both before their intake into the nest and after their placement on the cemetery. For the analyses of the possible role of the corpses as infection focars, we tested the reactions towards corpses of nestmate F. polyctena treated with spores and hyphae of the entomopathogenic fungi B. bassiana. The division of labor in waste management activities at caste and individual level was analyzed in the polymorphic ant species C. aethiops, which has workers that can be divided in different size castes, namely minor, media and major...

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