Preference and performance of Hypena opulenta on Vincetoxicum rossicum foliage from sun versus shade habitats

Characteristics of individual plants from the same species can differ significantly between habitats based on abiotic factors such as light intensity and temperature. In turn, these differences in plant quality can affect herbivores that feed on the plant. Here, we examined the effects of habitat on leaf characteristics for the invasive vine Vincetoxicum rossicum, as well as the preference and performance of its biological control agent, Hypena opulenta, on sun versus shade foliage. V. rossicum leaves grown in sunny habitats were tougher, thicker, and had lower water content than shade leaves. H. opulenta larvae consumed greater amounts of shaded foliage than sun foliage and were predominately night-active. H. opulenta larval development did not differ between sun and shade foliage diets; however, females preferred to oviposit on sun foliage. The underlying mechanisms of these results are discussed, as well as their implications for the biological control of Vincetoxicum species.