Data from: Transgenerational effects and the cost of ant tending in aphids

In mutualistic interactions, partners obtain a net benefit, but there may also be costs associated with the provision of benefits for a partner. The question of whether aphids suffer such costs when attended by ants has been raised in previous work. Transgenerational effects, where offspring phenotypes are adjusted based on maternal influences, could be important in the mutualistic interaction between aphids and ants, in particular because aphids have telescoping generations where two offspring generations can be present in a mature aphid. We investigated the immediate and transgenerational influence of ant tending on aphid life history and reproduction by observing the interaction between the facultative myrmecophile Aphis fabae and the ant Lasius niger over 13 aphid generations in the laboratory. We found that the effect of ant tending changes dynamically over successive aphid generations after the start of tending. Initially, total aphid colony weight, aphid adult weight and aphid embryo size decreased compared with untended aphids, consistent with a cost of ant association, but these differences disappeared within four generations of interaction. We conclude that transgenerational effects are important in the aphid–ant interactions and that the costs for aphids of being tended by ants can vary over generations.Aphid wet and dry adult weightThe file contains wet and dry weights (mg) of groups of sampled aphids (Aphis fabae), reared at low and high density on broad bean (Vicia faba).aphid_dry_weight_data.txtWeights of aphids reared with and without antsThe file contains data related to the (wet) weights of the aphids in the different cages at the time of collection (end of a generation), over the generations of the main experiment of the study.aphid_weight_data.txtWeight differences between unattended and ant-attended aphidsThe file contains differences of values of variables (from the data file aphid_weight_data.txt) between the two cylinders in a pair, for GenRel going from 0 to 4 (where 1 is the first ant attended generation in a trial). The differences are formed as the value for the ant attended cylinder in a pair minus the value for the unattended cylinder.aphid_paired_weight_data.txtAphid embryo size distributionThe file contains data on the distribution of aphid embryos over size categories, for a number of dissected adult aphids that were sampled from the main experiment of the study, including unattended and ant-attended aphids. Each row of the data file corresponds to one dissected aphid.aphid_embryo_data.tx