Multi-talented ants

Marching in long, exemplary lines, each carrying bright green leaves up to 50 times their own body weight, leaf-cutter ants are a common and fascinating sight in Costa Rica's forests.

Their hierarchical society is second only, perhaps, to humans in its complexity, and as such scientists in various countries have studied their remarkable skills in great detail for potential applications, including in biofuel production.

These tiny animals, known locally as zompopas, have many lessons for us, but for farmers in Costa Rica and further afield in the United States and Brazil, they are first and foremost a pest and a threat to their livelihoods.

But they are not your "standard pest", says Adrian Pinto of the University of Costa Rica, one of the country's leading ant experts. Up to seven million individuals can live in their underground colonies, and their queen's ability to produce up to 2,000 eggs an hour means the ants prove resilient to pesticides and the old-fashioned method of stomping.

"We definitely want to know how to control them," says Pinto. "They can defoliate a tree in one night. They are very voracious."

Still, the conundrum of how to control a pest that feasts on a variety of different crops is heightened in a country heavily dependent on agriculture yet equally famed worldwide for its progressive environmental policies - especially for someone whose life's passion has been the study of ants.

"It is a paradox I live with every day," says Pinto. "It is forbidden in Costa Rica to use the harmful environmental practice of showering crops in pesticide… Orange plantations have been abandoned because they are too close to national parks."

But Pinto is not only living with it, he is a key member of a project that is not only helping farmers learn how to control colonies, but that is teaching future generations what can be learned from ants.

Aim for the top

La Anita rainforest ranch nestles in lush countryside between the Miravalles, Rincon de la Vieja and Santa Maria volcanoes in the northwest of Costa Rica. A functioning finca - or farm - where local families practice subsistence agriculture, it also hosts regular seminars and science research courses for visiting U.S. high school students known as the Costa Rica Science Research Experience. Seeds of Change, a Minnesota-based non-profit, runs the program which aims to improve science skills with practical research on ant behavior.

For managers Pablo Cespedes and his wife Ana Perez, the project has not only helped the ranch become a center of ecotourism but has also helped mitigate the threat posed by ants to the cocoa fields on their sprawling ranch.

"One of the things we have learned is that once you get into the queen and kill the queen, then that is the end of that leaf-cutter ant nest," says Cespedes. "There is no way to replace her. Ants have no freedom, they are all born to do a certain job and all are sterile… In many ways it is the perfect communist society."

It's a more environmentally friendly way of killing the ants than dousing crops in pesticide and fungicides, says Cespedes.

'Superorganisms'

The children visiting La Anita under the Seeds of Change program help excavate the ant colonies, and set up their own experiments involving the ants. The organization is the brainchild of John Doleman, who during his time with the U.S space program, began to lament the dearth of new scientists coming through the education system as well as the over reliance on standardized testing.

He says the leaf-cutter ant, some of whose 47 known species have been around for more than 12 million years, provide the perfect field study.

"These ants are called a 'superorganism' because they can do many things that we as humans cannot and they do these things so well so they are a perfect learning tool," he says. "Once the kids get in the rainforest and do hands on work, they get completely engaged and motivated working on a real problem."

The capacity of leaf-cutters to degrade biomass to cultivate their own fungus garden to feed the nest, is a source of great interest for children and scientists alike.

Although the ant-grown fungus is susceptible to another parasitic organism, female ants are able to neutralize this through a particular bacteria produced in their own bodies. This ability to act as a natural chemist offers scientists and researchers a realm of possibilities, such as assisting in the search for new antibiotics.

"These ants are master microbiologists," says Pinto. "There are groups in pretty much all the developed countries conducting research into how this can be applied."

Another case in point is the research Brazilian leaf-cutter ants and their fungi are inspiring in the US, where scientists at the University of Wisconsin are looking at how the tiny creatures could help develop bioenergy and biofuels.

Anyone who has ever been bitten by a leaf-cutter can testify to the large impact they can make despite their modest size. Now it seems helping to save mankind by averting climate change could soon be added to their skill set.