Post-dropping behavior of potato aphids (Macrosiphum euphorbiae)
Abstract
Dropping behavior is an effective antipredator defense utilized by many insects including aphids, which drop from plants to lower plant parts or underlying substrates to avoid attack from predatory invertebrates. While research commonly focusses on triggers of dropping, less attention is given to what happens to prey individuals following escape drops. In this study, the duration of tonic immobility, recovery rates, and cases of “instant recovery” (re-clinging to lower plant parts) exhibited by potato aphids (Macrosiphum euphorbiae) that dropped from potted seedlings in response to introduced ladybird (Adalia bipunctata) adults, lacewing (Chrysoperla carnea) larvae, and a standardized tactile stimulus were investigated in relation to a range of environmental factors. Air temperature had a negative correlation with the duration of post-dropping tonic immobility; as temperature increased, time spent motionless decreased. Aphids also showed a pattern of increased recovery rate at higher temperatures. Aphids may be selected to move off the substrate quicker to avoid risks of overheating/desiccation at higher temperatures; and/or higher body temperature facilitates locomotion. Stimulus type also influenced recovery rate back to the original seedling, with aphids generally recovering after the standardized stimulus quicker than after dropping triggered by a real predator. Considering cases of instant recovery onto lower-reaches of the host seedling, seedling height influenced the likelihood of re-clinging, with aphids that managed to instantly recover dropping from, on average, taller seedlings than aphids that dropped to the substrate. Plant architecture could mitigate the costs of dropping for aphids, but further studies quantifying understory foliage cover are needed.
Citation
Humphreys , R K , Ruxton , G D & Karley , A J 2021 , ' Post-dropping behavior of potato aphids ( Macrosiphum euphorbiae ) ' , Journal of Insect Behavior , vol. First Online . https://doi.org/10.1007/s10905-021-09784-y
Publication
Journal of Insect Behavior
Status
Peer reviewed
ISSN
0892-7553Type
Journal article
Description
Funding: Perry Foundation, University of St Andrews, Scottish Government Rural and Environmental Sciences and Analytical Services Division.Collections
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