Chemical mimicry of the ant Oecophylla smaragdina by the myrmecophilous spider Cosmophasis bitaeniata: Is it colony-specific?
- 220 Downloads
Workers of most social insects can distinguish between nestmates and non-nestmates, and actively attack the latter if they attempt to intrude into the nest or surrounding territory. Nevertheless, there are many records of heterospecific organisms living within the nests of social insects, and they are thought to gain access through chemical mimicry. The salticid spider Cosmophasis bitaeniata lives within the leaf nests of the ant Oecophylla smaragdina, where it preys on the ant larvae. We investigated, using behavioural bioassays and chemical analyses, whether the previously reported resemblance of the cuticular hydrocarbons of ant and spider was colony-specific. Behavioural experiments revealed that the spiders can distinguish between nestmate and non-nestmate major workers and are less inclined to escape when confined with ants that are nestmates. More significantly, C. bitaeniata were more likely to capture ant larvae from nestmate minor workers than non-nestmate minor workers. The chemical analyses revealed that the cuticular hydrocarbon profiles of the spiders and the major workers of the ant colonies were colony-specific. However, the hydrocarbon profiles of C. bitaeniata do not match those of the major workers of O. smaragdina from the same colony. Perhaps the colony-specific cuticular hydrocarbon profiles of C. bitaeniata function to obtain prey from the minor workers rather than avoid eliciting aggression from the major workers.
KeywordsAraneae Colony-specific signal Cuticular hydrocarbon Formicidae Nestmate recognition
We thank Danielle Clode, Konrad Dettner, Laurent Keller, Ellen van Wilgenburg and some anonymous referees for their advice and comments on the manuscript; Trevor Anderson, Mark Blows and Richard Rowe for the use of their facilities at James Cook University; Valerie Todd Davies for identifying the spider and the financial support of the Australian Research Council (grant A19331563).
- Aitchison J (1986) The statistical analysis of compositional data. Chapman, LondonGoogle Scholar
- Brown WV, Watson JAL, Lacey MJ, Morton R, Miller LR (1996) Composition of cuticular hydrocarbons in the Australian harvester termite Drepanotermes perniger (Isoptera: Termitidae): variation among individuals, castes, colonies and locations. Sociobiology 27:181–197Google Scholar
- Cushing PE (1995) Description of the spider Masoncus pogonophilus (Araneae, Linyphiidae): a harvester ant myrmecophile. J Arachnol 23:55–59Google Scholar
- Cushing PE (1997) Myrmecomorphy and myrmecophily in spiders: a review. Fla Entomol 80:165–193Google Scholar
- Elgar MA (1993) Inter-specific associations involving spiders. Mem Queensl Mus 33:411–430Google Scholar
- Foelix RF (1982) Biology of spiders. Harvard University Press, CambridgeGoogle Scholar
- Hölldobler B (1983) Territorial behaviour in the green tree ant (Oecophylla smaragdina). Biotropica 15:241–250Google Scholar
- Hölldobler B, Wilson EO (1990) The ants. Harvard University Press, CambridgeGoogle Scholar
- Howard RW, Perez-Lachaud G, Lachaud JP (2001) Cuticular hydrocarbons of Kapala sulcifacies (Hymenoptera: Eucharitidae) and its host, the ponerine ant Ectatomma ruidum (Hymenoptera : Formicidae). Ann Entomol Soc Am 94:707–716Google Scholar
- Keegans SJ, Bille J, Morgan ED (1991) Volatile secretions of the green tree ant Oecophylla smaragdina (Hymenoptera: Formicidae). Comp Biochem Physiol 100B:681–685Google Scholar
- Liu ZB, Yamane S, Yamamoto H, Wang QC (2000) Nestmate discrimination and cuticular profiles of a temporary parasitic ant Lasius sp. and its host L. fuliginosus (Hymenoptera, Formicidae). J Ethol 18:69–73Google Scholar
- Liu ZB, Bagneres AG, Yamane S, Wang QC, Kojima J (2001) Intra-colony, inter-colony and seasonal variations of cuticular hydrocarbon profiles in Formica japonica (Hymenoptera, Formicidae). Insect Soc 48:342–346Google Scholar
- Porter SD (1985) Masoncus spider: a miniature predator of collembola in harvester ant colonies. Psyche 92:145–150Google Scholar
- Smith BH, Breed MD (1995) The chemical basis for nest-mate recognition and mate discrimination in social insects. In: Cardé RT, Bell WJ (eds) Chemical ecology of insects, vol. 2. Chapman, London, pp 287–317Google Scholar