The authors found that foundress wasps did not respond to the delivery rate of other group members but seemed to use the need of the dependent young as their main cue for provisioning. The authors speculate that this is likely due to the difficulty in individuals tracking the provisioning behaviour of other group member, as foundresses spend between 50-94% of their time off the nest foraging. Their results show that Polistes dominulus does not negotiate over care in a way predicted by either McNamara nor Johnstones models. By using offspring need they gain access to both current and historical levels of investment and this fits more with the recent work done by Lessells & McNamara (2012). This paper is a nice concise bit of science that aims and succeeds in testing a specific theoretical hypothesis.
link to paper: http://beheco.oxfordjournals.org/content/early/2013/10/03/beheco.art089.full.pdf?papetoc
Johnstone RA. 2011. Load lightening and negotiation over offspring care in cooperative breeders. Behav Ecol. 22:436–444.
Lessells CM, McNamara JM. 2012. Sexual conflict over parental investment in repeated bouts: negotiation reduces overall care. Proc R Soc B Biol Sci. 279:1506–1514.
McNamara JM, Gasson CE, Houston AI. 1999. Incorporating rules for responding into evolutionary games. Nature. 401:368–371.