Plasticity in resource choice: a time-limited butterfly prioritizes apparency over quality

STUDY ABSTRACT. Animals often plastically adjust resource choice to improve search efficiency or access to high quality resources. However, animals may encounter environments in which resources vary in both apparency and quality, making it difficult to simultaneously search efficiently and exploit high-quality resources. This work tested the hypothesis that time-limited animals will tend to prioritize resource apparency, sometimes over resource quality. We observed individual cabbage white butterflies as they searched for visually discriminable host plants (cabbage) and host plants that closely matched non-host plants in our arena (radish). We first show that cabbage is more discriminable than radish due to a waxy UV-reflective layer which, when removed, decreases butterfly search accuracy. When cabbage (with wax) and radish were both high quality, butterflies preferentially landed on cabbage, despite radish being a superior resource in terms of growth rate. When differential fertilizer application was used to lower cabbage’s quality relative to radish, butterflies slightly reduced their landings on cabbage compared to other treatments, but still showed a preference for cabbage (the more discriminable host). Furthermore, individuals with more pronounced preferences for the discriminable host made fewer mistakes during host searching. These results suggest that while resource choice is sensitive to changes in host quality, time-limited species continue to visit relatively more discriminable resources even when they are of low quality. We argue that an understanding of species ecology gives insights into when animals may fail to plastically adjust decision making. DATA DESCRIPTION. This file contains several tabs of data: --The "wax removal" experiment can be found in the "waxexp" tab --The "relative cabbage quality" experiment can be found in the "2g... labeled tabs, where the "by time" is divided into two time periods of the first and second ten landings on hosts --Data on larval growth rate is fond in the "growth rate" tab --Data on adult dissections (mature eggs in the ovaries) is found in the "dissection data" tab