Oecologia

, Volume 133, Issue 3, pp 430–438 | Cite as

No evidence for costs of being large in females of Orgyia spp. (Lepidoptera, Lymantriidae): larger is always better

  • Toomas Tammaru
  • Toomas Esperk
  • Ignacio Castellanos
Behavioural Ecology

Abstract.

Strong correlation between female body size and potential fecundity is often observed in insects. Directional selection favouring increased body sizes is thus predicted in the absence of opposing selection pressure. The evolutionary forces capable of counterbalancing such a 'fecundity advantage' are poorly documented. This study focuses on revealing the costs of large body size in the wingless females of Orgyiaantiqua and O.leucostigma, two related species of lymantriid moths. Extreme behavioural simplicity of these animals allows systematic assessment of various fitness components in conditions that are close to natural. A linear relationship between pupal weight and potential fecundity was observed. This association was found to be independent of particular rearing conditions. There was no evidence that the relationship between fecundity and body mass becomes asymptotic when body sizes increases. No component of fitness showed a negative phenotypic correlation with body size; some displayed a weakly positive one. In particular, pupal mortality, adult longevity, mating and oviposition success, as well as egg hatching rate and egg size, were established as independent of body size in a series of field and laboratory experiments. There was a very high overall efficiency of converting resources accumulated during the larval stage to egg masses. With no costs of large adult size, selective forces balancing the fecundity advantage should operate in the course of immature development. The strong dependence of realized fecundity on body size is considered characteristic of the capital breeding strategy.

Fecundity Mortality Evolution Optimality Tussock moth 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Copyright information

© Springer-Verlag 2002

Authors and Affiliations

  • Toomas Tammaru
    • 1
    • 2
  • Toomas Esperk
    • 1
    • 2
  • Ignacio Castellanos
    • 3
  1. 1.Institute of Zoology and BotanyTartuEstonia
  2. 2.Institute of Zoology and HydrobiologyUniversity of TartuTartuEstonia
  3. 3.Department of EntomologyUniversity of MarylandCollege ParkUSA

Personalised recommendations