Discovery of a second mushroom harvesting ant (Hymenoptera: Formicidae) in Malayan tropical rainforests

Ants have evolved an amazing variety of feeding habits to utilize diverse food sources. However, only one ant species, Euprenolepis pro cera (EMERY, 1900) (Formicidae: Formicinae), has been described as a specialist harvester of wild-growing mushrooms. Mushrooms are a very abundant food source in certain habitats, but utilizing them is expected to require specific adaptations. Here, we report the discovery of another, sympatric, and widespread mushroom harvesting ant, Euprenolepis wittei LAPOLLA, 2009. The similarity in nutritional niches of both species was expected to be accompanied by similarities in adaptive behavior and differences due to competitive avoidance. Similarities were found in mushroom acceptance and harvesting behavior: Both species harvested a variety of wild-growing mushrooms and formed characteristic mushroom piles inside the nest that were processed continuously by adult workers. Euprenolepis procera was apparently dominant at mushroom baits displacing the smaller, less numerous E. wittei foragers. However, interspecific competition for mushrooms is likely relaxed by differences in other niche dimensions, particularly the temporal activity pattern. The discovery of a second, widespread mushroom harvesting ant suggests that this life style is more common than previously thought, at least in Southeast Asia, and has implications for the ecology of tropical rainforests. Exploitation of the reproductive organs of fungi likely impacts spore development and distribution and thus affects the fungal community.