Effects of symbiont Hamiltonella defensa on parasitism and multiparasitism of pea aphids (Acyrthosiphon pisum) by Aphidius ervi and Aphelinus abdominalis

Data collected in the laboratory on the effects of symbiont Hamiltonella defensa in pea aphids Acyrthosiphon pisum on outcomes of multiparasitism by two parasitoid species (Aphidius ervi and Aphelinus abdominalis). Aphids either possessed the symbiont Hamiltonella defensa (‘Hamiltonella’ in column ‘Symbiont’) or had been cured of their symbiont infection using selective antibiotics (‘None’). In Experiment 1, Aphelinus abdominalis attacked first; in Experiment 2 Aphidius ervi attacked first. In both experiments, aphids were subjected to two parasitism treatments, three days apart (indicated by columns labelled ‘First_treatment’ and ‘Second_treatment’). Each treatment had three possible options: ‘Aphidius’ (parasitism by Aphidius ervi), ‘Aphelinus’ (parasitism by Aphelinus abdominalis) or ‘None’ (aphids not exposed to parasitoids). The headings ‘Aphelinus_mummy’, ‘Aphidius_mummy’, ‘Live’ and ‘Dead’ refer to the possible outcomes for aphids.