Live and inanimate predator-associated cues suppress the population of sap-feeding prey and induce polyphenism

Non-consumptive effect of predation is a well-researched subject of which certain non-consumptive and predator-mimetic facets are yet to be investigated in plant-parasite systems One clone of the green peach aphid Myzus persicae (Sulzer), raised on a model crop Brassica oleracea (L.), was exposed to different regimes of risks associated with ladybird Coccinella septempunctata (L.). This encompassed consumption, consumption alternated by non-consumptive effects, isolated predators, dead predator, predator dummy, as well as dummy, plants or soil cued with predator-borne suspension, and predator removal (exposure to plants previously visited and marked by a predator). Over time, the respective risk regimes variably negatively impacted the prey population; the corpses, cued plants and dummies had considerable persistent negative effects on aphid reproductive success, contrary to the observation under predator removal. By the end of the experiment, polyphenism (winged morph production) also differed and was animated under the presence of a starved isolated predator; but faded when a predator corpse was present; and vanished under the dummy. Our findings, in this model aphid-crop system, contribute to the rapidly developing area of the ecology of fear, as we provide insights and novel means for aphid management that merit further examination across different eco-agricultural contexts.