Investigations of the interactions between aphids and ants in multispecies ant communities and an experimental investigation of some ethological aspects of ant-aphid interactions were carried out in mixed forests at Novosibirsk Academic Centre, from 1998-2002. The eight species of ants investigated were characterized by different levels of territorial organization and interaction with aphids, which were associated with different degrees of specialization of the worker ants. The most myrmecophilous species of aphids (24 out of 33 species identified) were associated with the red wood ants. By placing Coccinella septempunctata Linnaeus (Coleoptera: Coccinellidae) in aphid colonies it was shown that only ants with large protected territories attacked the adults and larvae of the predator. Other species of ants either protected aphids only from adult ladybirds or did not guard them at all. Moreover, only individuals of Formica s. str., which has specialized workers, did not switch to collecting protein food. However, aphids make up a considerable part of the prey of ants, in which non-myrmecophilous aphids predominate (about 60-100% of the aphid prey). Moreover, ants only killed unattended or damaged myrmecophilous aphids. Formica s. str., which has the highest level of social and territorial organization, provides aphids with the most services and is the dominant species forming symbiotic relationships with aphids in the communities studied.
Five polymorphic microsatellite loci of the arboreal ant Allomerus decemarticulatus (Myrmicinae) were isolated and characterized. The amplification and polymorphism of seven additional microsatellite loci, previously developed for the ant species A. octoarticulatus and Wasmannia auropunctata, were also tested and the amplification conditions necessary for genotyping the complete set of 12 multiplexed markers in A. decemarticulatus determined. The number of alleles per locus ranged from three to 15 and observed heterozygosity varied from 0.09 to 0.95. Cross-species amplification of these loci was also successfully achieved in additional species of the same ant subfamily, Myrmicinae. This set of microsatellite markers will be used in studies on the mating system and population genetic structure of Myrmicinae in general and A. decemarticulatus in particular.
In social insects, the high variability in the number of queens per colony raises fundamental questions about the evolution of altruism. It is hypothesized, for instance, that nestmate recognition should be less efficient in polygynous than in monogynous colonies because the presence of several breeders increases the diversity of genetically determined recognition cues, leading to a less specific colonial signature. Recent studies, however, have shown that the link between the number of queens in a colony and the recognition abilities of its members is more complex than previously suggested. Here, we studied intraspecific aggression, diversity of potential recognition cues and genetic structure of colonies in the highly polygynous ant Crematogaster pygmaea. Our results reveal that workers of this species are clearly aggressive towards non-nestmates in field experiments but not in more artificial bioassays conducted in Petri dishes, underscoring the importance of context-dependent aspects of the assessment of nestmate recognition. Behavioural, genetic and chemical data show that C. pygmaea is a multicolonial species, forming spatially restricted and well-defined entities. Therefore, the postulated negative correlation between recognition ability of workers and queen number in a colony is not supported by the results of this study., Rachid Hamidi ... [et al.]., and Obsahuje seznam literatury
The phylogenetic relationships among Palaearctic species of the ant genus Tetramorium and its social parasites of the genera Strongylognathtus, Anergates and Teletomyrmex, were investigated electrophoretically at 21 presumptive enzyme loci. The data set comprising 33 species was analysed with distance (UPGMA, Neighbor-joining and least squares statistics) and parsimony methods (independent allele, minimum turnover and mutation coding) in order to rule out analysis-dependent effects. Several groupings were consistently resolved by all procedures. Observed branching patterns support the placement of the three parasite genera and their hosts into the Palaearctic species group of Tetramorium (tribe Tetramoriini). The genus Strongylognathus forms a monophyletic group in which the slave-makers of the S. huberi group constitute the sister group of the inquilines S. testaceus and S. karawajewi (S. testaceus group). Most species of the S. huberi group show very low genetic differentiation. However, little consensus has been found with regard to which Tetramorium species are the closest relatives of Strongylognathus.
According to the electrophoretic data, social parasitism in Palaearctic tetramoriine ants has evolved independently at least twice. Though inquilinism once arose from slave-making ancestors in Strongylognathus, the extreme inquilines Anergates atratulus and Teleutomyrmex schneideri are clearly set apart from the Strongylognathus clade in phylogenetic analyses. Thus, extreme inquilinism cannot be regarded as the endpoint of a single parasitic lineage in the Tetramoriini. In these highly advanced inquilines, evolutionary rates at allozyme loci appear to be higher than those of their Tetramorium hosts. The results do not unambiguously reveal whether Anergates and Teleutomyrmex arose jointly or independently from Tetramorium ancestors. However, a combined analysis using all available evidence supports the former hypothesis. The finding that the Tetramorium parasites are not the closest relatives of their respective host species is discussed in relation to current theories for the evolution of social parasitism.