Mate Quality Affects Reproductive Effort in a Paternally Investing Species

Abstract

Females of many species exercise postcopulatory mate choice by increasing the amount of resources put into reproduction after mating with a preferred male. This phenomenon is termed cryptic female choice in insects and differential allocation in birds. In this study I investigate the possibility that males and females vary their reproductive effort depending on the quality of their mate. Females of the comma butterfly, Polygonia c-album (Nymphalidae) lay their eggs on a range of host plants, including stinging nettle (Urtica dioica) and sallow (Salix caprea). Previous studies have shown that females reared on sallow are more fecund than females reared on stinging nettle, whereas males reared on stinging nettle produce spermatophores with higher protein content than sallow-reared males. Radioactive label experiments showed that females use male donations for egg production. When females mated males that provided larger donations, they used proportionally more of these proteins for egg production but also increased their own reproductive effort. Female lifetime reproductive output was not found to differ with respect to the larval diet of their mate, but females mated to high-quality males lived significantly longer than females mated to males providing them with smaller donations, which suggests that females can use male nutrients also for somatic maintenance. These results are discussed in relation to female cryptic choice and differential allocation hypotheses.