How important is the ant-termite interaction in African rain forests?

Lead Research Organisation: The Natural History Museum
Department Name: Life Sciences

Abstract

Natural ecosystems provide important services to humans, such as the generation of food, the prevention of flooding, and carbon sequestration. However, they are increasingly under threat from global changes, such as habitat destruction and global warming. In order to maintain natural ecosystems it is vital to understand how they work. Trophic interactions between groups of organisms - interactions involving one organism eating another - are one of the main factors determining how these ecosystems are structured. But the nature of these interactions is poorly known, even in well-studied systems. One such key trophic interaction is that between ants and termites. Both groups make up a large proportion of the biomass in tropical ecosystems across the world, and are known to be 'ecosystem engineers' i.e. they are one of the main contributors to the structure of the ecosystem. Termites do this by moving soil around, and eating large amounts of dead leaves, wood and even soil. Ants also move soil around, and also consume a wide variety of animals and some plants. Since a majority of the species of ants are at least partly predatory, and termites are a highly abundant and moderately nutritious, it has often been assumed that ants eat a lot of termites. However, this has only been demonstrated for a small number of species, as much predation of termites by ants takes place underground. We propose to quantify the interaction between ants and termites not by direct observation of predation events, but by looking for termite genetic material in the guts of ants. We already have collections of ants and termites from soil cores taken in rain forest in Gabon. The different species of ant present have already been identified morphologically (from their appearance). For each species of ant we will search for termite DNA in the guts of up to 30 individuals. For certain parts of their genetic material, each termite species has its own unique sequence of base pairs. Consequently we can tell not only that a particular species of ant has eaten a termite, we can also tell which species of termite it has eaten. This will allow us to divide up the species of ant into three different categories: 1. Those that do not eat termites 2. Those that do eat termites, but do not have any preference for a particular termite species, or group of termite species 3. Those that specialise on a particular termite species or group of termite species The resulting data will allow us to construct a partial food web for the different species of ants and termites, and will allow us to make predictions about the impacts of processes such as habitat conversion and climate change on the structure of natural ecosystems.
 
Description Termites and ants comprise the single largest contribution to animal biomass and perform vital ecosystem functions in tropical rain forests. Although ants prey on termites, at the community level the linkage between these groups is poorly understood. Thus, assessing the distribution and specificity of ant termitophagy is of interest. We describe an approach for quantifying ant-termite food webs based on sequencing termite DNA (COII) from ant guts and apply this to a soil-dwelling ant-termite community from tropical rain forest in Gabon. We extracted DNA from 255 ants from 39 species. Of these, 16.1% of individual ants tested positive for termite DNA in their guts, with BLAST analysis confirming the identity of 34.1% of these termites. Although ant species varied in the proportion of workers in which termite DNA was detected, ranging from 63% (5/7) in Camponotus sp. 1 workers to 0% (0/7) in Ponera sp. 1 workers, there was no evidence that termite consumption was heterogeneously spread across ant species or subfamilies, nor was there evidence of species-specific predation of ant species on termite species. In all three ant species with identifiable termite DNA in more than one individual (out of a total of eight species) we found multiple termite species represented. Furthermore, the two termite species that were detected on multiple occasions in ant guts were in both cases found in multiple ant species. Our data support the hypothesis that unspecialised termite predation by ants is widespread and highlights the use of molecular approaches for future studies of ant-termite food webs.
Exploitation Route Further studies of ant-termite interactions.
Sectors Environment

 
Title DNA probe for ant-predated termites 
Description Use of Cytochrome Oxidase II sequences as way of seeing what termites have been eaten ants. 
Type Of Material Biological samples 
Year Produced 2013 
Provided To Others? Yes  
Impact Expansion of research on ant-termite interactions 
 
Description Metagenomics of ant prey 
Organisation University of South Bohemia
Country Czech Republic 
Sector Academic/University 
PI Contribution Working on the adavnces made in the original NERC gtrant we are ionvolved in a more ambitious project to use modern DNA techniques to discover what is eaten by Malaysian ants.
Collaborator Contribution They will do the metagenomics eotk is their lab.
Impact None yet.
Start Year 2016
 
Description Nature Live presentations (NHM) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Nature Live allows communication of NHM staff to the general public.

Recruitment of additional volunteers for the research group.
Year(s) Of Engagement Activity 2010,2011,2013,2014,2015