The traditional view of ant to plant services is that ants protect host plants against herbivores. However, other services that are more cryptic may also take place. In this talk, I propose two further potential ant to plant services – (i) fertilization of plant canopies and (ii) plant pathogen control. Firstly, I will show that weaver ants (Oecophylla smaragdina) deposit N-containing faecal droplets on the foliage of their host plants and present a recent study showing that coffee leaves were able to take up N from these droplets and allocate it within the plant. Secondly, I suggest that ant hygiene (e.g. ant produced antibiotics) may extend beyond the ant nest and in some cases may lead to control of pathogens on the ants´ host plants. I will briefly review evidence for this claim and present preliminary empirical data showing reduced incidence of two fungal apple diseases on apple trees attended by wood ants (Formica polyctena).
Joachim Offenberg is Senior Researcher at Department of Bioscience, Aarhus University, Denmark. His work has focused on applied myrmecology, comprising the use of ants as biocontrol agents in plantation crops, additional ecosystem services provided by ants (including production of edible ants), and management/culturing of weaver ant colonies.