The parasitic caterpillars of Maculinea (Lepidoptera: Lycaenidae) need to be adopted and nursed by ants of the genus Myrmica (Hymenoptera: Formicidae). Each Maculinea species is locally associated with one or a few main and often several secondary host species. To determine whether the parasite-host associations bear marks of cophylogenetic constraints, we reconstructed phylogenies of Maculinea and Myrmica using DNA sequence data. We searched for evidence of cospeciation with a tree-independent (ParaFit) and tree-based (TreeFitter) method. This did not reveal any indication of phylogenetic host tracking in Maculinea. This agrees with earlier insights, which emphasise that as most of the potential host ant populations are never infested by Maculinea, the selective pressure of the butterflies on Myrmica is likely to be slight. Each Maculinea species also specialises on one or a few host plant species before adoption by ants. We suggest that Maculinea species have a substantial potential to accommodate evolutionarily to geographically changing ranges of potential Myrmica hosts, available at the oviposition sites of the butterflies. We use recently published evidence on geographically varying host ant species to discuss a suite of plausible scenarios of adaptive shifts to new Myrmica host species. and Gunther Jansen, Kari Vepsäläinen, Riitta Savolainen.
Butterflies of the genus Phengaris have a highly specialised life cycle involving an obligatory relationship with Myrmica ants. A knowledge of the host ant specificity is essential for understanding the relationship between a particular Phengaris species and its hosts and also important for the conservation of these butterflies. Data on host ant specificity were collected in Poland, the Czech Republic, Slovakia and Ukraine. Five different Myrmica species were used by P. teleius as hosts (M. scabrinodis, M. rubra, M. ruginodis, M. rugulosa and M. gallienii) and at most localities it was not possible to distinguish a primary host - i.e. several Myrmica species were parasitized to similar extents. Three populations of P. nausithous were found in Poland and Ukraine. In every case, M. rubra was its primary host, although in the Kraków region (Poland) two nests of M. scabrinodis and two of M. ruginodis were infested by this butterfly species. P. alcon in the four populations investigated in Poland and Ukraine invariably only used M. scabrinodis as a host despite the presence of other Myrmica species. These results obtained suggest lack of host specificity in P. teleius and high host specificity in P. nausithous, which mainly uses M. rubra as its host across Europe. Moreover, the three populations of P. alcon investigated seem to be highly specific and use M. scabrinodis as a host, which confirms the high local specialisation of these populations.
In Europe there are only a few species of the syrphid fly Microdon, which live in the nests of various genera of ants. For most of these rare flies, details of their biology, larval behaviour and relationships with their hosts are still not yet well known. In this paper we present data on the life cycle, feeding behaviour and growth pattern of Microdon myrmicae, a social parasite of Myrmica ants and compare it with two species of Maculinea butterflies similarly parasitizing Myrmica ant colonies. M. myrmicae has three larval instars and overwinters as a third instar. Eggs and 1st instar larvae are ignored by ants, which indicate that they are “chemically insignificant”. 2nd and 3rd instar larvae feed on small ant brood. M.myrmicae larvae grow rapidly from May to July and later in the year the host colony only serves as shelter for overwintering. Like Maculinea alcon, larvae of M. myrmicae are numerous in Myrmica nests and more numerous than those of Maculinea teleius. Since the larvae of Microdon feed on an abundance of young ant brood, they experience low level of scramble competition and although many may develop in an ant’s nest they have probably little effect on host colony fitness., Magdalena Witek ... [et al.]., and Obsahuje seznam literatury
Competition is a major force organizing ant communities and results in co-occurring species evolving different strategies for foraging and use of space. Territorial species, as top dominants exclude each other, while shaping the local ant communities both qualitatively and quantitatively. In this study we examined how two territorial species, Formica polyctena and Lasius fuliginosus, can coexist in adjacent territories over long periods of time, and whether they affect co-occurring species of ants in different ways. Field observations in the absence and in the presence of baits were carried out around a L. fuliginosus nest complex surrounded by a polydomous F. polyctena colony in S Finland in 2007–2009. Both species controlled their territories, but were affected by changes in the abundance of the other species and the distance from L. fuliginosus’ main nest. They did not have the same effect on the subordinate species in the absence of baits, but the abundance of Myrmica spp. recorded at baits was negatively affected by both of the territorial species. The preferences of the different species for the artificial food sources differed: L. fuliginosus and F. polyctena preferred tuna to honey and Myrmica spp. honey to tuna. More individuals of the subordinate species were recorded in the territory of F. polyctena than of L. fuliginosus, although conflicts with this territorial species were also recorded. During the three years of the study almost no overlaps in the territories of the two territorial species were recorded, and there were mostly minor shifts in the boundaries of the territories. Differences between the two territorial species in their use of space and competitive effects ensured their coexistence at this particular site in Finland., Wojciech Czechowski ... [et al.]., and Obsahuje seznam literatury