Extrafloral nectar and above- and below-ground herbivory

Many plants produce extrafloral nectar (EFN) as a response to above-ground herbivory, and below-ground herbivores can also affect its production. Huang et al. subject seedlings of Triadica sebifera (tallow tree) to herbivory by above-ground adults and/or below-ground larvae of a specialist beetle, Bikasha collaris, and find that simultaneous herbivory induces more EFN production than below-ground herbivory alone. However, the highest EFN production is induced by above-ground herbivory when below-ground herbivores are absent, and the results therefore suggest that below-ground herbivory can limit the defensive response of plants to above-ground attack.