On the expression of co-operative feeding behaviour in 3rd instar Drosophila melanogaster larvae

Under poor nutritional conditions, 3rd instar Drosophila melanogaster larvae will work collaboratively in feeding clusters to obtain resources that cannot be reached individually. To better understand the conditions that influence the expression of this behaviour we examined the frequencies, the size and the membership in vials of flies that were initially seeded with either 100 or 200 eggs each using flies from both a large, outbred population and a replicate population that was homozygous for the bw allele. Overall, more feeding clusters, containing more larval participants were observed in the higher density vials compared to the lower density vials, consistent with the idea that this social behaviour is a response to dwindling resources in the environment. The presence of the bw allele did not result in greater egg-to-adult mortality, nor did it result in lower participation in feeding clusters.