Drop when the stakes are high: adaptive, flexible use of dropping behaviour by aphids

Humphreys, R. K. , Ruxton, G. D. and Karley, A. J. (2021) Drop when the stakes are high: adaptive, flexible use of dropping behaviour by aphids. Behaviour, 158(7), pp. 603-623. (doi: 10.1163/1568539X-bja10083)

Abstract

For herbivorous insects, dropping from the host plant is a commonly-observed antipredator defence. The use of dropping compared to other behaviours and its timing in relation to contact with a predator was explored in both pea aphids (Acyrthosiphon pisum) and potato aphids (Macrosiphum euphorbiae). Pea aphids dropped more frequently in response to ladybird adults (Adalia bipunctata) than lacewing larvae (Chrysoperla carnea). Potato aphids mainly walked away or backed-up in response to both predator types; but they dropped more frequently relative to other non-walking defences when faced with ladybird adults. Contact with a predator was an important influencer of dropping for both species, and most drops occurred from adjacent to the predator. Dropping appears to be a defence adaptively deployed only when the risk of imminent predation is high; factors that increase dropping likelihood include presence of faster-foraging predators such as adult ladybirds, predator proximity, and contact between aphid and predator.

• Item Type: Articles
• Additional Information: RKH was funded by the Perry Foundation and the University of St Andrews. AJK is supported by the strategic research programme funded by the Scottish Government’s Rural and Environment Science and Analytical Services Division.
• Keywords: Aphididae, defence, dropping behaviour, predator-prey behaviour, predator-prey interaction, risk assessment.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: McKenna, Dr Rosalind
• Authors: Humphreys, R. K., Ruxton, G. D., and Karley, A. J.
• College/School: University Services > Learning and Teaching Services Division
• Journal Name: Behaviour
• Publisher: Brill Academic Publishers
• ISSN: 0005-7959
• ISSN (Online): 1568-539X
• Published Online: 30 March 2021
• Copyright Holders: Copyright © 2021 The Authors
• First Published: First published in Behaviour 158(7): 603-623
• Publisher Policy: Reproduced under a Creative Commons License