Evol Ecol Res 4: 407-420 (2002)     Full PDF if your library subscribes.

The physiological costs of being small in a parasitic wasp

A. Rivero* and S.A. West

Institute of Cell, Animal and Population Biology, University of Edinburgh, Kings Buildings, Edinburgh EH9 3JT, UK

Author to whom all correspondence should be addressed.
e-mail: ana.rivero@ed.ac.uk

ABSTRACT

Knowledge of the relationship between body size and fitness is essential in many models of parasitoid evolutionary ecology. One clear point emerging from previous studies is that the relationship between size and fitness can depend strongly (qualitatively and quantitatively) on the environment in which it is measured. Our results show that, in the parasitoid wasp Nasonia vitripennis, the relationship between parasitoid size and fitness is strongly dependent on the nutritional status of the female; being small is more costly when food is not available. Lipid availability is the main factor mediating the relationship between size and fitness. Small females suffer disproportionately the costs of not feeding because they emerge with small lipid reserves and thus have to rely more heavily on carbohydrates for survival and reproduction. In other words, feeding is more important for small females. Our results (1) provide a physiological explanation for why laboratory estimates of the size–fitness relationship are not as steep as field estimates and (2) suggest that females are likely to show size-dependent foraging and feeding strategies.

Keywords: lipids, parasitoids, resource allocation, size–fitness relationship.

DOWNLOAD A FREE, FULL PDF COPY
IF you are connected using the IP of a subscribing institution (library, laboratory, etc.)
or through its VPN.

 

        © 2002 Ana Rivero. All EER articles are copyrighted by their authors. All authors endorse, permit and license Evolutionary Ecology Ltd. to grant its subscribing institutions/libraries the copying privileges specified below without additional consideration or payment to them or to Evolutionary Ecology, Ltd. These endorsements, in writing, are on file in the office of Evolutionary Ecology, Ltd. Consult authors for permission to use any portion of their work in derivative works, compilations or to distribute their work in any commercial manner.

       Subscribing institutions/libraries may grant individuals the privilege of making a single copy of an EER article for non-commercial educational or non-commercial research purposes. Subscribing institutions/libraries may also use articles for non-commercial educational purposes by making any number of copies for course packs or course reserve collections. Subscribing institutions/libraries may also loan single copies of articles to non-commercial libraries for educational purposes.

       All copies of abstracts and articles must preserve their copyright notice without modification.