Plant quantity affects development and reproduction of a gregarious butterfly more than plant quality

The larvae of insect herbivores feed on plants that may vary nutritionally (qualitatively and/or quantitatively) over the course development. Plant quality change in response to interactions with biotic environment turn affect development and biomass insects feeding these plants. However, many gregariously comparatively small limited also experience variation quantity plant food available. Pieris brassicae L. (Lepidoptera: Pieridae) is a gregarious butterfly species laying clutches 10–150 eggs are often laid brassicaceous plants, including used this study, Brassica nigra (Brassicaceae). A single B. provides insufficient resources for an entire brood P. brassicae. In we investigated effect both performance when When compared effects changes induced by (1) aphid infestation, (2) exposure pathogenic non-pathogenic bacteria, (3) inbreeding depression, which all stresses known quality, pupal mass larval time were fairly similar. We then examined quantitative constraints during immature mass, correlated strongly adult size, longevity, fecundity. Female longevity fecundity negatively duration starvation No significant male was found female reproduction longevity. Thus, more affected than qualitative terms reproduction.