Take flight: predation risk induces wing polyphenism and dispersal in the aphid Myzus persicae

Predation risk can generate strong non-consumptive effects that influence prey physiology, morphology and behaviour, often leading to adaptive changes without direct consumption. In aphids, such effects may induce winged (alate) morphs that facilitate dispersal, yet the extent to which predation risk couples morphological plasticity with movement behaviour and survival advantages remains poorly understood, particularly under varying predator densities.

We investigated how predation risk from the ladybird Harmonia axyridis influences wing induction, dispersal behaviour and survival in the aphid Myzus persicae using experimental series initiated with 50 nymphs or 50 adults. Predator presence above a certain density significantly increased the number of alate progenies in both nymph- and adult-initiated series, with stronger effects at higher predator densities. In the adult-exposure series, alate induction exhibited a non-linear pattern, with significant increases in alate numbers at predator densities of five and ten, but not at one. In the nymph-initiated series, a significant increase was observed only at the highest predator density (ten). Dispersal responses were morph-specific: alate aphids showed significantly increased movement under elevated predation risk, whereas apterous aphids exhibited no significant change. Predation assays further revealed significantly lower consumption of alate compared with apterous aphids for both male and female predators, indicating a survival advantage associated with wing induction.

These findings suggest that predator-induced phenotypic plasticity integrates morphological and behavioural responses to enhance prey survival. This creates a potential trade-off for biological control, because high predator densities may trigger winged morph production and facilitate pest dispersal to neighbouring crops; however, this assertion requires field validation. © 2026 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.