6.2 Intra-species communication & Foraging in social insects  (Page 7/9)

Between honeybee species, hive location preference has directly influenced differentiation of dancing techniques through evolution. Beekman et al., found that Apis florea does not increase the relative precision of its dance based on context, whereas A. mellifera does (2008) as more and more bees begin and sustain a waggle-run advertising a highly specific site (Oldroyd et al. 2008). A. florea has no need for dance consensus or the high levels of accuracy because recruiters do not need to express exact locations. Their potential nest sites, such as exposed branches on trees, are easily identifiable even from a distance. The complication of A. mellifera’s dance is believed to have arisen when the species changed nesting habits from open-dwellings to cavity nest sites (Beekman et al. 2008)(See Table 1 for dance summary). Because it is difficult to pinpoint a possible nest site that is within a cavity as opposed to in an open area, the bees needed to evolve a more precise system of communication. This was made possible through relative consensus on the profitability of a possible nest site (Oldroyd et al. 2008). In the mellifera species, ‘piping’, which is achieved by vibrating the thorax against the surface of the hive, is performed by dance-watchers in order to elicit a stop in the waggle-dance (Pastor and Seeley 2005). Once a nest site has been agreed upon and the quorum reached, workers will engage in ‘piping’ and ‘buzz-running’ to signal that it is time to evacuate the old nest (Oldroyd et al. 2008).

Piping is sometimes supplemented by a unique ‘tremble dance’ in which the forager will rotate its body around an axis, vibrating in place (Seeley 1992). Seeley informs us that this behavior occurs when there is a surplus influx of nectar, and that it signals both that bees should stop recruiting and that more workers should begin receiving nectar for storage (1992). Conversely, if there are not enough foragers, sometimes what is called the

‘shaking’ dance, executed by quick up and down vibrations of the thorax, will signal recruits to go to the ‘dance floor’ (or comb surface) to receive information on the newly found resource (Hölldobler&Wilson 2009). But how does A. mellifera reach a consensus between large numbers of individuals on a particular nest site?

Table 1. The Dances of A. mellifera