Phylogenetic relationships among social parasites and their hosts in the ant tribe Tetramoriini (Hymenoptera: Formicidae)

Abstract

Abstract. The phylogenetic relationships among Palaearctic species of the ant genus Tetramorium and its social parasites of the gen era Strongylognathus, Anergates and Teleutomyrmex, 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 group ings 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 nionophyletic 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 Te leutomyrmex 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 re spective host species is discussed in relation to current theories for the evolution of social parasitism.

Phylogenetics of Australian Acacia thrips: the evolution of behaviour and ecology

“…Second, diverse studies on Hymenoptera have indicated that social parasitism has evolved frequently, but parasitic clades are often, or even predominantly, closely related to the host species (Wilson, 1971). Although this clearly does not hold true for all Hymenoptera, it is often the case that social parasites have a sister-group relationship with their hosts (e.g., ants, Wilson, 1971;Sanetra and Buschinger, 2000;Ward, 1996;bees, Lowe and Crozier, 1997;Michener, 1974;Wilson, 1971). Our results strongly indicate that in the Acacia thrips there has been only a single origin of kleptoparasitism and inquilinism and, as far as our taxonomic representation goes, without reversions to non-parasitic habits.…”

Unusual Ant Hosts of the Socially Parasitic AntAnergates atratulus(Schenck, 1852) (Hymenoptera, Formicidae)

“…Although A. atratulus was reported previously mainly in Tetramorium caespitum (Linnaeus, 1758) and T. impurum (Förster, 1850) [4][5][6][7] nests within the Tetramorium caespitum/impurum complex, it was also recorded from Sicily (Italy) from a nontypical low altitude (300 m) in a nest of T. diomedeum Emery, 1908, which is a member of the Tetramorium ferox complex [8]. Future clarification of the complicated taxonomic composition of the Tetramorium caespitum/impurum complex will probably enlarge the number of known host ant species parasitized by A. atratulus [5].…”

“…Future clarification of the complicated taxonomic composition of the Tetramorium caespitum/impurum complex will probably enlarge the number of known host ant species parasitized by A. atratulus [5].…”

Sympatric speciation through intraspecific social parasitism

“…The suggestion is based on the observation that all inquiline ants are either closely related to their hosts (loose form of Emery's rule), or are the closest relatives to their hosts (strict form of Emery's rule) (33). Although the evidence for the loose form of Emery's rule is convincing (34), phylogeny-based studies on inquiline ants, bumblebees, and wasps have rejected the strict form of Emery's rule (35)(36)(37)(38); consequently, the studied inquilines cannot support sympatric speciation.…”