Argentina's Attack of the Killer Ants

In Genesis, God tells Adam and Eve to "be fruitful and multiply", exercising dominion over "every living thing that moves on the earth".  Well, you know what they say about the best laid plans of mice and men.

Winegrowers in Mendoza in Argentina are being terrorized by a species of fauna that has them on the run. This particular nuisance is capable of lifting 10-50 times their body weight and sometimes more. They are collegiate, resourceful, and extremely well organized. Acting in unison, they are endowed with sinister-looking mandibles, scurrying about with the urgency of a Black Friday sales shopper. Yes, I'm talking about ants.

"It's important to understand that ants are a plague that are impossible to eradicate. So the main focus it's how we can reach a balance between their life and the health of the vineyard," says Franco Bastias, head of agronomy and sustainability at Domaine Bousquet. "They are an issue from the moment vines are planted; ants are a very common pest which affect nearly every producer."

According to Bastias,  these resourceful insects devour, at lightning speed,  all the green parts of the vines:  leaves and young shoots.  Thus, photosynthesis becomes a little bit tricky, and ripening berries is out of the question. Some 28 species of ants currently reside in the Mendoza region, including Dorymyrmex Tener, a formidable insect with a nasty nip. Omnipresent in the terrain of South America, certain species can lead to a dramatic reduction of yield in local agriculture.

I spoke to several wine producers last week, all of whom agreed that ant colonies are a major headache. "In Mendoza, we have always had a problem with ants due to Mendoza being a desert. You can imagine how appealing a vine is versus other plants in a desert climate," explains Daniela Maezzatesta, Terrazas de los Andes' sustainability manager.

However, there is another vital part of this story, which is the unintended consequences of Terrazas de los Andes commitment to the green agenda. Today, all of the estate's vineyards are certified as sustainable (Bodegas de Argentina certification) and are currently in the process of organic certification. The inevitable corollary of this realignment towards organic viticulture was a set of ambitious initiatives to encourage greater biodiversity within the vineyards; Terrazas de los Andes is installing 200 wooden nest boxes (made from recycled wood) to encourage birds to reproduce there.

Yet, as Herve Birnie-Scott (founder of Terrazas de los Andes) freely admits, the drive to go green can present a new set of challenges. Namely, it's harder to deal with indigenous pests and other problems that occur throughout the growing season. And no: you cannot always rely on bigger beasts – birds and mammals – to do the job for you. "The biggest challenge, so far, in converting to organic methods has been the ants. There's no efficient organic product to fight them, so you must remove the anthills from your vineyards by hand. And doing it right you still lose as much as 5 percent of your production," he says.

"Once all your vineyards are organically farmed, permanent improvement is the rule of the game. Indeed, you have to be an even better viticulturist when you go organic, focusing on prevention and anticipation. That’s the only way, as you don't have any more synthetic chemicals to set things right."

But even winegrowers who liberally spray pesticides, dawn to dusk, are worried. They concede, albeit reluctantly, that climate change will likely worsen this serious problem of pint-sized leaf cutters. After all, no one is predicting that Mendoza will become less parched in light of rising temperatures; ants thrive in these dry conditions. And so the race is on to find a lasting solution to this problem.

"For the time being, we have not found an organic/sustainable way of managing this issue that is efficient enough. We have tried destroying their nest, sulfur, Diatomita (diatomaceous earth) but so far none of these have worked 100 percent," admits Claudio Mestre, Terrazas de los Andes' technical director.

© Image by Paul Henri Degrande from Pixabay | In other parts of the world, wild boars and even baboons have been damaging vineyards.

Meanwhile,  the volume of synthetic chemicals used in several wine regions, including Mendoza, has fallen significantly.

"The region now has 7300 hectares of vines under organic management, which represents approximately 11 percent of all organic viticulture in the world," says Franco Bastias.

This is a positive development, both in terms of environmental protection and enhanced soil/vine health. But as restrictions on phytosanitary products increase, growers across the world must maintain a difficult balance between adhering to a more eco-friendly paradigm and protecting their crop. As a result, encouraging biodiversity is increasingly touted as the most pragmatic solution by a growing number of wineries.  Indeed, their reverence is almost cult-like.

"We pay great attention to biodiversity in and around our vineyard. This is to encourage a rich natural environment that will allow the development of natural resistance to fight against this or that disease," says Jeanne Fabre, director of wine tourism at Famille Fabre in Languedoc, and president of the Millésime BIO Commission.

"It is because it is complex that the balance we achieve is stable. We always try to work with nature and its local resources, never against it. For example, the installation of RCW [fragmented ramial wood, a woodchip application made by chopping up small tree branches] can encourage the development of mole rats; it will be necessary to put in perches so that birds of prey can regulate the population."

This is attractive rhetoric, and yet it glosses over the difficulties in managing population sizes; relying on birds to kill all your vermin is hardly an exact science, particularly if your feathered friends develop a taste for Grenache. Thus, in order to maximize the potential benefits of encouraging flora/fauna, the accurate selection of species and varieties are key points in the decision-making process.  Unfortunately, a miscalculation can have dire consequences.

"At Terrazas de los Andes we have worked hard to identify our native fauna and promote its preservation. However, there is a danger in reintroducing exotic species," agrees  Daniela Maezzatesta.

"For example, we are collaborating in a project that monitors the presence of an exotic bird in our region, Sturnus vulgaris (estornino pinto), that may be a potential plague. Also, in our annual bird review, we are studying the presence of Myopsitta monachus (cotorra argentina) that could also cause damage."

Nevertheless, several leading proponents of biodiversity have told me that its positive impact extends far beyond protecting the vines from predatory organisms. Viticulturists frequently highlight biodiversity's positive impact on soil fertility, the reduction of risk of erosion and the improvements to soil structure and water holding capacity. Some are even convinced there is a definitive link between enhanced biodiversity in the vineyard and superior wine quality.

"We are truly convinced that preserving the biodiversity and creating exceptional wines are linked. Creating great wines implicates to pay attention to the one thousand details. Through our observation and involvement, we seek to have an overall vision and a consistency in each of our action, from the pruning to the final product," enthuses Languedoc winemaker Gérard Bertrand.

Worshipping biodiversity has obvious and wide-reaching appeal. Yet as the experience of Terrazas de los Andes demonstrates, it is not the panacea for all pest-related issues. Not least because the ants outnumber the birds 1000 to 1. For the moment, growers have to accept a certain amount of crop loss.

Consolation, however, can always be found in the knowledge that animal incursions are a global issue.  In the Western Cape, roving populations of baboons eat crops and sometimes threaten lives.  Moreover, according to Jeanne Fabre, "major damage is being done by the wild boar population in the Languedoc, and there is no easy solution". In 2018, two French hunters were injured in the region of Loire-Atlantique when a wild boar attacked them. The animal was said to have weighed 220 lbs.

Of course, most of us love to see animals frolicking in a vineyard setting.  Just be careful: some may take a bite out of you as well.