Polyrhachis loweryi (Formicinae): A guest ant parasitizing Rhytidoponera sp. (Ponerinae) in Queensland, Australia

Abstract

At the type locality near Miles in Queensland, Australia a queenright colony of Polyrhachis loweryi was found (1 dealate queen, 91 workers, males and brood) within a colony of Rhytidoponera sp. (near aciculata), whereas other colonies of this Rhytidoponera species contained only a few workers of P. loweryi. For experiments and behavioural observations P. loweryi and its hosts were kept in the laboratory for some time. The queenright P. loweryi colony constructed closed nests out of soil and plant fibres, within the host nest, and only containing Polyrhachis specimens. P. loweryi workers in part, remained amid the assembly of Rhytidoponera, from whom they obtained carbohydrate and protein food. In addition, Polyrhachis workers regularly left the host nest. They were able to collect liquid carbohydrate food and to distribute it among conspecific nest mates via trophallaxis. The care of the P. loweryi brood was fully done by P. loweryi itself. However, Rhytidoponera workers were observed carrying P. loweryi brood in addition to their own brood. In artificially induced nest relocations, P. loweryi was able to move to a new nest independently from its host ants, displaying the typical invitation behaviour, trail laying behaviour, and leader independent trail communication found in other members of the genus. Rhytidoponera sp., which in addition to inconspicuous trail marking, performs nest relocation via social carrying, rarely but regularly also carried P. loweryi to the new nest. Whereas Rhytidoponera sp. workers were carried in the typical ponerine posture, P. loweryi workers were carried by them in the formicine posture. We conclude that P. loweryi is best described as a guest ant of Rhytidoponera sp.. The species seems to be less well integrated into the societies of its Rhytidoponera sp. host than the closely related P. lama, a social parasite of Diacamma sp. in Java.In both Polyrhachis species workers from queenright colonies perhaps emigrate with a few eggs or larvae in order to rear them in neighbouring host nests. The adaptive and predispositional reasons for the phyletic development of this parasitic relation remain unclear.

Phylogeny, divergence-time estimation, biogeography and social parasite–host relationships of the Holarctic ant genus Myrmica (Hymenoptera: Formicidae)

“…This is understandable, because similarity between parasite and host facilitates their coexistence (Buschinger, 1986). Rare exceptions to the loose form of the rule are inquilines of the formicine genus Polyrhachis, which parasitise ponerine hosts (Maschwitz et al, 2000(Maschwitz et al, , 2003. The strict form of Emery's rule (SFER) is an evolutionary-biologically attractive hypothesis.…”

Compound nesting of Strumigenys sp. (Myrmicinae) and Diacamma sp. (Ponerinae), and other nesting symbioses of myrmicine and ponerine ants in Southeast Asia

“…the species involved are not closely related (for example Pyramica (Kyidris) yaelogyna in colonies of Strumigenys loriae (Wilson and Brown, 1956), Diacamma sp.1 and Polyrhachis lama (Maschwitz et al, 2000(Maschwitz et al, , 2001 or Rhytidoponera sp. and Polyrhachis loweryi (Maschwitz et al, 2003). The evolution of such parasites can only be explained via the "xenobiosis route" (Wilson, 1971), and xenobiosis cannot be understood without intermediary steps from originally separate colonies moving into compound nests.…”

Social and genetic structure of a supercolonial weaver ant, Polyrhachis robsoni, with dimorphic queens

“…With over 450 species divided into 12 subgenera (Bolton, 1995;Dorow, 1995), nesting habits range from subterranean in either terrestrial or intertidal habitats (Nielsen, 1997), to lignicolous, lithophilic, and arboreal (Liefke et al, 1998;Robson, 2004), with nests constructed of various combinations of carton, larval and spider silk (Robson and Kohout, 2005). Colony structure can be highly variable, with some species establishing nests through either single or multiple queens (Sasaki et al, 2005;Yamauchi et al, 1987) or obligatory parasitic relationships with other species of ants (Maschwitz et al, 2003). The Australian weaver ant Polyrhachis robsoni (previously referred to as P. doddi?…”