Oviposition Colour Preferences in a Grass‐Feeding Butterfly

Herbivorous insects use both visual and chemical cues to locate suitable host plants in diverse vegetation. Because colour is among the most salient visual cues, such insects are expected to have preferences for particular colours when searching for host plants. To test whether colour preferences play a role during host‐plant selection, we performed a series of oviposition‐choice experiments on common evening brown butterflies ( Melanitis leda L.; Lepidoptera: Nymphalidae) using artificial grasses. This species uses a wide variety of grasses as host plants but nevertheless shows strong preferences among species of grass. We determined preferences between primary colours (red, blue and green), and preferences between greens that vary in (a) brightness (luminance), (b) hue (adding some blue or green) and (c) saturation (adding various amounts of grey). We found that these butterflies readily oviposited on artificial grass and responded to hue, brightness and saturation. They appeared to prefer bright green, pure green or slightly red‐shifted green, and green of high saturation. The acceptance of artificial grass shows that visual cues, possibly together with mechanical cues, can be enough to induce oviposition behaviour. The preferences appear to fit with the host‐plant use of this species. Our results highlight the importance of visual cues for ovipositing insects.