Effect of experience on foraging behavior towards artificial nectar guide in the cabbage butterfly, Pieris rapae crucivora (Lepidoptera: Pieridae)

We examined the effects of nectar guides of artificial flowers on the feeding behavior of naive and experienced butterflies, Pieris rapae crucivora Boisduval. A colored spot on artificial flowers triggered the responses of naive butterflies to probe around the spot on the flower, which contributed to their finding the source of nectar. This means that the spot acted as a nectar guide. Butterflies correlated nectar guides with the nectar source and improved their foraging efficiency by experience. Such improvement was not observed on flowers without a guide, which suggested that the nectar guide should play an important role in the improvement of foraging efficiency in P. rapae butterflies. Furthermore, butterflies foraged more consistently on flowers with a guide than those without guide after three days of conditioning for either flower type. If this foraging manner is widespread among other insect pollinators, visit consistency based on insect learning might have been a selective force for the nectar guide in natural entomophilous flowers.