Further Observations on the Dissolution of Mutualism between Cecropia and Its Ants: The Malaysian Case

Abstract

Cecropia peltata L., an early successional neotropical tree species, was introduced in Malaysia in the 1950s. Although the Azteca ants with which it is usually associated in the mainland neotropics are not present in Malaysia, Cecropia trees grow faster, suffer less herbivore damage, and are less often liana-laden than sympatric Malaysian pioneer tree species. These findings cause us to further evaluate the Cecropia-Azteca relationship and to consider other attributes of Cecropia that reduce its susceptibility to both vines and herbivores. Interpretation of the data on rates of leaf loss to herbivores is complicated, however, by the recency of Cecropia introduction and by the observation that native early successional trees at our study site in Malaysia suffered much less herbivory than native early successional trees on Barro Colorado Island in Panama and possibly elsewhere in the neotropics. Finally, substantial variation among individuals in the production of ant-related structures (trichilia and Mullerian bodies) was observed in Malaysia, variation that is presumably masked in the mainland neotropics.