The ontogeny of the interaction structure in bumble bee colonies: A MIRROR model

In this paper we present an individualoriented model of the behaviour of bumble bees on the comb. We show that the combination of the population dynamics of a bumble bee colony and simple behaviour of the adult bees on the comb is sufficient to generate the social interaction structure of the colony (and it ontogeny) as observed by van Honk and Hogeweg (1981); the latter studied the dominance interactions in a captive Bombus terrestris colony in relation to worker oviposition by pattern analysis techniques. We also demonstrate how the generated/observed interaction structure can cause a switch from the production of worker offspring to the production of generative offspring. The model is an application of the MIRROR modelling strategy (Hogeweg and Hesper 1979, 1981a, b, c). In this modelling strategy the emphasis is on (i) local definition of entities (individuals), (ii) experience-based interrelations between individuals and (iii) observability. Such models enable us to generate the 'macro' behaviour (in casu of bumble bee colonies) from the 'micro' behaviour (in casu of individual bees) without including (implicitly or explicitly) assumptions about macro relations in the specification of the behaviour of the individuals. Thus the model shows that only those features of the behaviour of the individual bees explicitly incorporated in the model specification are needed to generate the observed organisational pattern in the nest. The model does not, of course, rule out the possibility that other factors play a role in the organisation of live colonies.