Fear of predation alters clone-specific performance in phloem-feeding prey

Abstract

Fear of predation has been shown to affect prey fitness and behaviour, however, to date little is known about the underlying genetics of responses to predator-associated risk. In an effort to fill this gap we exposed four naïve clones of green peach aphid (Myzus persicae), maintained on the model crop Brassica oleracea, to different types of cues from aphid lion (Chrysoperla carnea). The respective predation risks, we termed Fear Factors, were either lethal (consumption by predator), or non-lethal (non-consumptive predator-associated cues: plant-tethered predator cadavers and homogenised shoot-sprayed or soil-infused blends of predator remains). Our results show that the non-lethal risk cues differentially impeded prey reproductive success that varied by clone, suggesting genotype-specific response to fear of predation. Furthermore, whether plants were perceived as being safe or risky influenced prey responses as avoidance behaviour in prey depended on clone type. Our findings highlight that intra-specific genetic variation underlies prey responses to consumptive and non-consumptive effects of predation. This allows selection to act on anti-predator responses to fear of predation that may ramify and influence higher trophic levels in model agroecosystems.

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

“…The risk effect here was non-consumptive by inanimate predator-borne cues. This treatment draws on our recent work on the effects of predator cadavers on aphid population growth (Khudr et al ., 2017).…”

“…g ., olfactory cues). This treatment draws on our recent work on the applied infusion method for soil manipulation to directly or indirectly impede pest population growth (Khudr et al ., 2017).…”

“…g ., the presence of impaired predators ( i . e ., altered experimentally to no longer consume the prey) (Nelson et al ., 2004; Nelson and Rosenheim, 2006), the mere presence of a predator (McCauley et al ., 2011; Kersch-Becker and Thaler, 2015), and predation threat including induction by predator-borne cues (Preisser and Bolnick, 2008; Ferrari et al ., 2010; Ninkovic et al ., 2013; Khudr et al ., 2017).…”

“…The effects triggered by predator cues (Norin, 2009) diffuse through prey population and intensify in effect due to aphid pheromone communication (de Vos et al ., 2010; Keiser, 2012, Ingerslew and Finke, 2017), thereby inducing varied responses such as polyphenism (Weisser et al ., 1999), and/or changes in reproductive success (Khudr et al ., 2017). In this regard, using isolated predators or inanimate objects cued by predator info-chemicals as a form of risk to affect parthenogenetic phloem-feeding insects has not received enough attention compared to the effects of the deployment of impaired predators (Nelson et al ., 2004; Nelson and Rosenheim, 2006).…”

“…For example, impaired predators have been shown to negatively impact on aphid reproduction (Nelson and Rosenheim, 2006). Moreover, encounters between green peach aphid Myzus persicae and corpses of its lacewing predator Chrysoperla carnea (Stephens) or plants pre-treated with lacewing cues have been reported to induce anti-predator avoidance behaviour and to lead to a differential reduction in aphid fitness as a consequence of fear of predation (Khudr et al ., 2017). However, defining the effects of different non-consumptive cues ( e .…”