Effects of the maternal and pre‐adult host plant on adult performance and preference in the pea aphid,Acyrthosiphon pisum

Abstract 1. The taxon known as the pea aphid, Acyrthosiphon pisum, is composed of a series of host plant associated populations and is widely used as a model system to explore ecological speciation and the evolution of specialisation. It is thus important to know how maternal and pre‐adult experience influences host plant utilisation in this species. 2. The relative importance of the maternal and pre‐adult host plant for adult fecundity and host preference was investigated using three aphid clones collected from Lathyrus pratensis and maintained on Lathyrus or Vicia faba. 3. No significant effects of the maternal host plant on offspring fecundity were detected. 4. The host plant on which the aphid grew up influenced adult fecundity, although in a complex way that depended on both the adult host plant species and when after transfer to the test plant fecundity was assessed. 5. All three clones preferred to colonise Lathyrus over Vicia, and this preference was stronger for aphids raised on Lathyrus. 6. The significance of the results for studies of the evolution of specialisation and speciation that employ A. pisum is discussed.