Predation risk differentially affects aphid morphotypes: impacts on prey behavior, fecundity and transgenerational dispersal morphology

Abstract

To avoid predation, prey initiate anti-predator defenses such as altered behavior, physiology and/or morphology. Prey trait changes in response to perceived predation risk can influence several aspects of prey biology that collectively contribute to individual success and thus population growth. However, studies often focus on single trait changes in a discrete life stage or morphotype. We assessed how predation risk by Harmonia axyridis affects several important traits in the aphid, Myzus persicae: host plant preference, fecundity and investment in dispersal. Importantly, we examined whether these traits changed in a similar way between winged (alate) and wingless (apterous) adult aphid morphotypes, which differ in morphology, but also in life-history characteristics important for reproduction and dispersal. Host plant preference was influenced by the presence of H.axyridis odors in choice tests; wingless aphids were deterred by the odor of plants with H.axyridis whereas winged aphids preferred plants with H.axyridis present. Wingless aphids reared in the presence of ladybeetle cues produced fewer offspring in the short-term, but significantly more when reared with exposure to predator cues for multiple generations. However, winged aphid fecundity was unaffected by H.axyridis cues. Lastly, transgenerational plasticity was demonstrated in response to predation risk via increased formation of winged aphid morphotypes in the offspring of predator cue-exposed wingless mothers. Importantly, we found that responses to risk differ across aphid polyphenism and that plasticity in aphid morphology occurs in response to predation risk. Together our results highlight the importance of considering how predation risk affects multiple life stages and morphotypes.

Predation Risk Effects of Lady Beetle Menochilus sexmaculatus (Fabricius) on the Melon Aphid, Aphis gossypii Glover

“…The avoidance effects were significant for lady beetle males, females, or third-instar larvae, with approximately 60% choosing the control (without the lady beetle). In another study, peach aphids M. persicae also showed a significant avoidant response towards lady beetle H. axyridis [10]. Aphids can recognize the volatiles emitted by lady beetle and will avoid areas where lady beetle are present.…”

“…The predation risk of Harmonia axyridis Pallas (Coleoptera: Coccinellidae) alters the host preference of the aphid Myzus persicae Sulz. (Hemiptera: Aphididae), reduces the offspring, and increases the number of winged aphids in the offspring [10]. The chemical from the footprint of Coccinella septempunctata Linnaeus (Coleoptera: Coccinellidae) has been shown to reduce the number of aphids produced by Rhopalosiphum padi Linnaeus (Hemiptera: Aphididae) [11].…”

Transgenerational plasticity in aphids reared in a poor-resource environment

“…Transgenerational responses could be adaptive for offspring if they show phenotypic variation across environments, with increased resistance to certain stressful conditions ( Agrawal et al, 1999 ). TGP has been observed in many arthropods in response to various stresses such as heat ( Diaz et al, 2021 ; Ledón-Rettig 2023 ), drought ( Le Hesran, 2020 ) and predation ( Hermann et al, 2021 ; Mondor et al, 2005 ). TGP occurs when parents modify both the trait mean and slope of the offspring reaction norm, whereas in the presence of maternal effects alone, the offspring phenotype is indeed influenced by the mother, but no plasticity in response to a changing environment is observed.…”

Salivary carbonic anhydrase II in winged aphid morph facilitates plant infection by viruses

“…Aphids evolved a specialized wing dimorphism with wingless (apterous) and winged (alate) morphs under different environments ( 20 , 21 ). The winged morph can better cope with harsh ecological contexts involving biotic or abiotic stresses, whereas the wingless morph is capable of achieving higher fitness under more benign conditions ( 22 , 23 ). With regard to virus transmission, winged aphids are more competent vectors for NPTVs due to their high frequency of migration and probing ( 24 , 25 ).…”