Factors affecting the number of leaves included in the shelters of the leaf-folding caterpillar, Vanessa indica (Lepidoptera: Nymphalidae)

ABSTRACT

Larvae of the Indian red admiral butterfly, Vanessa indica (Herbst, 1794), fold the leaves of the host plants along the midvein to construct shelters. Usually, one leaf is used for every shelter, although more than one leaf are sometimes used. To determine the conditions under which larvae use more than one leaf to construct a shelter, a field investigation of the larval shelters was conducted. Early instar larvae used multiple leaves in a shelter when a larger leaf served as the main leaf. In comparison, in later instars used multiple leaves when a smaller leaf served as the main leaf. When an early instar larva uses a large, tough leaf, it may not be able to fold it sufficiently and there may be gaps in the surface of the shelter. In such a case, a larva in the early instar may add nearby leaves to cover the gaps, so that the shelter has more than one leaf. Because later instar larvae can fold a leaf tightly, their shelters have no gaps. When later instar larvae use a small leaf, multiple leaves will be needed to expand the shelters within which they hide and feed.

KEY WORDS:
Indian red admiral butterfly; leaf size; multiple-leaf shelter; shelter construction; trenching behavior