Abstracts (first author)
Hotspots of social parasites of Myrmica ants
Colonies of social insects, such as ant nests, represent a well protective environment, which is also a good sources of food. Many organisms have evolved to live within ant societies showing different degrees of interaction, ranging from mutualism to parasitism. Social parasites exploit the colony resources over a long period of time. Myrmica ants are hosts for larvae of lycaenid butterflies belonging to the genus Maculinea as well as for larvae of the syrphid fly Microdon myrmicae. Parasitic larvae spend most of their life cycle inside host nests and, depending on the feeding strategy, they prey on the ant brood or they are fed directly by ant workers. Although it is suppose that social parasites are much rare in comparison to their hosts there are places where a few species of social parasites co-occur exploiting the same pool of resources. The aims of this research were to assess factors influencing the infestation of Myrmica nests, as well as to study the host specificity pattern and parasite distribution in the social parasite community. The study was carried out at two sites inhabited by different social parasite communities, each comprising varying proportions of Maculinea teleius, M. nausithous, M. alcon and Microdon myrmicae. Data were collected twice, at the beginning and in the end of parasite larval development. The most important factor influencing the number of parasitic larvae was the size of ant nests. The biggest Myrmica colonies adopted more larvae and they also provided better conditions, which allow survival of the highest number of parasitic caterpillars. At both communities, competition among social parasites posed strong enough selection on M. teleius population to use Myrmica host species not exploited by other social parasites. Thus, in some cases not only the availability of host species but also the presence of other competitors might shape the coevolution between particular species of social parasites and their ant hosts.