Colony odor

For this lifestyle to succeed, the wasp larvae obviously must avoid being recognized. If the ants were to detect them, they would suffer the fate of other intruders discovered in the nest expulsion or death. Although some intruders escape detection in ant nests because they resemble their ant hosts, Orasema larvae, pupae, and adults all are easily distinguishable from their hosts, at least by the human eye. Fire ants, however, are much more concerned with smell than physical appearance. Fire-ant odor and local colony odor are what matter to them. By these scents, ants identify their own nestmates as distinct from other species and even from fire ants belonging to rival colonies. The wasps strategy to avoid discovery is to smell just like fire ants. Larvae, pupae, and even adult wasps carry the distinctive scent of their particular fire ant colony. Shortly after the adult wasps leave the ant nest, this ant odor begins to fade. 

Lahav S., Soroker V., Vander Meer R. K. and Hefetz A. (2001) Segregation of colony odor in the desert ant Cataglyphis niger. J. Chem. Ecol. 27, 927-943. 

Crozier, R. H. and Dix M. W. (1979). Analysis of two genetic models for the innate components of colony odor in social Hymenoptera. Behav. Ecol. Sociobiol., 4, 217-224. 

Soroker, V., Fresneau, D. and Hefetz, A. (1998). Formation of colony odor in ponerine ant Pachychondyla apicalis. J. Chem. Ecol., 24,1077-1090. 

Nestmate recognition is believed to involve the matching of a label, the so-called colony odor (i.e. the chemical profile containing the nestmate cues), with a template (the neural representation of the colony odor stored in the memory), and depending on the... 

Hefetz, A. (2007). The evolution of hydrocarbon pheromone parsimony in ants (Hymenoptera Formicidae) - interplay of colony odor uniformity and odor idiosyncrasy a review. Myrmecol. News, 10, 59-68. 

Bagneres, A.-G., Errard C., Mulheim C Joulie, C and Fange, C. (1991). Induced mimicry of colony odors in ants. J. Chem. Ecol., 17, 1641-1664. 

Errard, C. (1986). Role of early experience in mixed-colony odor recognition in the ants Manica rubida and Formica selysi. Ethology, 72, 243-249. 

The multifaceted function of cuticular hydrocarbons necessitates further theoretical as well as empirical clarification. For example, their use as both fertility signals and nest-mate recognition pheromones may seem contradictory, since the first function requires within-nest idiosyncrasy, i.e., for discriminating fertile from sterile individuals, while the second function requires within-colony odor uniformity. The response threshold hypothesis (Le Conte and Hefetz, 2008) attempts to resolve this apparent conflict in function, as well as to provide a suitable framework for future experiments to test specific parts of the hypothesis. 

Signature Mixtures Variable Individual, family, colony odors Learning required... 

Fig. 2.3 Most animals have both anonymous pheromone signals and signature mixtures (Wyatt 2010). This is demonstrated in the cuticular hydrocarbons of the queenless ant Dinoponera quadriceps (Monnin et al. 1998). A gas chromatographic analysis of the cuticular hydrocarbons on the alpha female, the only fertilized and egg-laying individual in the colony, shows the anonymous hydrocarbon pheromone 9-hentriacontene (indicated by the asterisk) characteristic of alpha females in all colonies, together with the diverse range of other hydrocarbons which make up the colony odor. Her fellow colony members have the colony odor but lack the 9-hentriacontene. Ants photograph, courtesy Thibaud Monnin. Gas chromatogram, Monnin et al. (1998), with permission...

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