Endophytic fungi reduce leaf-cutting ant damage to seedlings

Abstract

Our study examines how the mutualism between Atta colombica leaf-cutting ants and their cultivated fungus is influenced by the presence of diverse foliar endophytic fungi (endophytes) at high densities in tropical leaf tissues. We conducted laboratory choice trials in which ant colonies chose between Cordia alliodora seedlings with high (E high ) or low (E low ) densities of endophytes. The E high seedlings contained 5.5 times higher endophyte content and a greater diversity of fungal morphospecies than the E low treatment, and endophyte content was not correlated with leaf toughness or thickness. Leafcutting ants cut over 2.5 times the leaf area from E low relative to E high seedlings and had a tendency to recruit more ants to E low plants. Our findings suggest that leaf-cutting ants may incur costs from cutting and processing leaves with high endophyte loads, which could impact Neotropical forests by causing variable damage rates within plant communities.

Symbiotic fungi alter plant chemistry that discourages leaf‐cutting ants

“…A previous study showed that leaf-cutting ants prefer to cut leaves with low rather than high colonization by endophytic fungi (Bittleston et al, 2011). Here we show that changes in the chemical characteristics of leaves resulting from their symbiosis with leaf endophytes are associated with most of the observed ant preferences.…”

Convergence in Multispecies Interactions

“…Molecular techniques have greatly increased knowledge of microbial diversity and functions. For example, we now know that gut bacteria influence human weight, nutrition, and immune function [24]; bacterial and yeast endosymbionts provide insects with nutrition and protection (reviewed in [25]); and fungal endophytes deter plant pathogens and herbivores [26][27][28]. However, the majority of the world's microbes-and their interactions and functionsremain difficult to characterize.…”

An Overview of Integrated Management of Leaf-Cutting Ants (Hymenoptera: Formicidae) in Brazilian Forest Plantations

“…Endophytic fungus on plant leaves can also reduce the foraging and processing efficacy of leaf-cutting ants [101,102] probably because of low volatility compounds released after their wounding [103].…”