Limited effects of the maternal rearing environment on the behaviour and fitness of an insect herbivore and its natural enemy

Slater, J. M., Gilbert, L. , Johnson, D. and Karley, A. J. (2019) Limited effects of the maternal rearing environment on the behaviour and fitness of an insect herbivore and its natural enemy. PLoS ONE, 14(1), e0209965. (doi: 10.1371/journal.pone.0209965) (PMID:30633753) (PMCID:PMC6329576)

Abstract

The maternal rearing environment can affect offspring fitness or phenotype indirectly via ‘maternal effects’ and can also influence a mother’s behaviour and fecundity directly. However, it remains uncertain how the effects of the maternal rearing environment cascade through multiple trophic levels, such as in plant-insect herbivore-natural enemy interactions. Pea aphids (Acyrthosiphon pisum) show differential fitness on host legume species, while generalist aphid parasitoids can show variable fitness on different host aphid species, suggesting that maternal effects could operate in a plant-aphid-parasitoid system. We tested whether the maternal rearing environment affected the behaviour and fitness of aphids by rearing aphids on two plant hosts that were either the same as or different from those experienced by the mothers. A similar approach was used to test the behaviour and fitness of parasitoid wasps in response to maternal rearing environment. Here, the host environment was manipulated at the plant or plant and aphid trophic levels for parasitoid wasps. We also quantified the quality of host plants for aphids and host aphids for parasitoid wasps. In choice tests, aphids and parasitoid wasps had no preference for the plant nor plant and aphid host environment on which they were reared. Aphid offspring experienced 50.8% higher intrinsic rates of population growth, 43.4% heavier offspring and lived 14.9% longer when feeding on bean plants compared to aphids feeding on pea plants, with little effect of the maternal rearing environment. Plant tissue nitrogen concentration varied by 21.3% in response to aphid mothers’ rearing environment, and these differences correlated with offspring fitness. Maternal effects in parasitoid wasps were only observed when both the plant and aphid host environment was changed: wasp offspring were heaviest by 10.9–73.5% when both they and their mothers developed in bean-reared pea aphids. Also, parasitoid wasp fecundity was highest by 38.4% when offspring were oviposited in the maternal rearing environment. These findings indicate that maternal effects have a relatively small contribution towards the outcome of plant-aphid-parasitoid interactions.

• Item Type: Articles
• Additional Information: JMS was funded through The Scottish Food Security Alliance: Crops by the James Hutton Institute and the Universities of Aberdeen and Dundee. DJ received support from the N8 Agri-Food programme. LG and AJK were supported by the strategic research programme funded by the Scottish Government’s Rural and Environment Science and Analytical Services Division.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Gilbert, Dr Lucy

Creator Roles

Gilbert, L.: Conceptualization, Funding acquisition, Methodology, Supervision, Writing – review and editing

• Authors: Slater, J. M., Gilbert, L., Johnson, D., and Karley, A. J.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: PLoS ONE
• Publisher: Public Library of Science
• ISSN: 1932-6203
• ISSN (Online): 1932-6203
• Copyright Holders: Copyright © 2019 Slater et al.
• First Published: First published in PLoS ONE 14(1):e0209965
• Publisher Policy: Reproduced under a Creative Commons License