We are up river in Belize at the Maya Mountain Research Farm these next two weeks, teaching our tenth annual Permaculture Design Course here. This year we have 16 local Mayan farmers, healers, businessmen and women, trainers in development work, and students from the US, UK, Russia and Greece. Our own essay this week, about a different topic, is being guest-published at Club Orlov on Monday, so we thought we would publish here a short piece by our host, Christopher Nesbitt.
This is a small nest of a leaf cutter ant queen, establishing a colony. We tend to see them in tired land, rebuilding soils, assaulting the biological obscenity of monoculture, especially citrus, and aerating soils, hauling carbon down to the subsoil, allowing oxygen and water to infiltrate soils. They will do some damage to native species, like cacao, but mostly concentrate on introduced species. Chemicals are not a constant necessity. I have been farming in a tropical setting since 1988, and I have NEVER used any biocides.
I am farming about 15 acres of a 70 acre piece of land. Most of the land I am working right now is old cattle pasture or abandoned citrus. You would not be able to tell looking at it. I live in a pretty lush forest of trees, with hundreds of species. Most of what I am doing is creating a stacked polyculture with a large diversity of species, ranging from banana, papaya and pineapple, to timber, to fuel wood, to tree legumes, to food, to medicinals and market crops that fit into the matrix of the farm, things like cacao, coffee and vanilla. We do have some gardens, and we are expanding on the periphery of the land to create coconut dominated polycultures and feed banks for pigs, but the majority of the farm resembles the primary rainforest in structure, with less diversity, and with all the species being selected by us. We get both termites and leaf cutter ants. While they can both be a nuisance, if we step back a bit, we can see some of the services and products they provide.
Think of the presence of leaf cutter ants as being an indicator of an ecosystem out of balance, of being a cure for damaged soils. The lack of leaf cutter ants may mean a healthy ecosystem, or massive use of chemicals, including aldrin. I think of leaf cutter ants as being nature's way of rehabilitating damaged soils. You really only see leaf cutters in the wake of a biological catastrophe, hurricanes, fire damaged land, or places like played-out milpa, after the window of 3-6 years of annuals productivity has dwindled out, and the return on energy invested is not worth the effort, and the land in question is being fallowed, or in the wake of the life of a citrus grove, abandoned banana plantations or damaged cattle pasture.
Most biological "catastrophes" are man made, with monocultures being the biggest biological catastrophe, sustained through work and inputs. These systems are only sustainable in simplistic economic models of capital invested in input and labor versus kilograms per hectar x dollar per kilogram. Often, in terms of calorie based accounting, they are net losses of energy. Without cheap petroleum to subsidize their profitless existence, they would not exist.
I have lots of leaf cutter ants here in Belize, and while they can be a nuisance, they seldom damage a tree beyond the capacity of recovery. The biggest problem is that, if one is looking to produce marketable quantities of a single species, you have painted a sign on your ass that tells nature "bite me." Nature obliges. While working industriously to undo the biological abomination of a monoculture the ants are the rescue squad, aerating the soil, allowing water to percolate in, and hauling carbon, all things that help damaged soil to recover.
Monocultures lead to leaf cutter ants. Leaf cutters have adapted to citrus in particular, with a preference for Washington navels and Valencia oranges. They are less excited by grapefruit or limes. What we call Jamaica lime here in Belize is practically immune to leaf cutter ants (and tolerates poor soil). One way to avoid leaf cutters is to have a diversified farm in the first place, but any young polyculture in the lowland humid tropics is going to be prone to leaf cutter ants. When the land is more mature, it will be less susceptible, but not immune.
We see a lot of leaf cutter nests. I periodically dig up the mounds, looking for their fungus gardens, the subterranean chambers where they use the leaves for a substrate for their fermentations. When the young flightless queens are in the embryonic stage, they are like milk shakes for chickens. Even whacking on the surface of the nest will excite the colony. Ants, being social insects, react to any perceived threat to the queen by swarming. Any disturbance on ground level will result in massive retaliation by the soldier ants, which are like micro pit bulls.
My chickens have visually imprinted on soldier ants and queen ants as being food. Soldier ants come out, looking to attack the source of the disturbance, and chickens happily eat them, racing about to snatch them up, converting a problem into eggs, meat and manure. I invest a bit of energy in harassing the colony, and the result is a smorgasborg of insect protein for my chickens. I have eliminated a few nests with this technique.
You can also make barriers of lemon grass, or vetiver, which leaf cutter ants do not like, lay cannavalia ensoformis leafs in their trails, which has antifungal properties and eventually, accidentally, will be taken into their nest, working better than a Stuxnet virus. If I put the soil from one nest across the trail of another nest they will not cross the trail (for a while). All of these are more about management than destruction.
The important thing is to see the inherent limitations of sustainably managing your farm. Certain crops are leaf cutter ants' favorite foods. If you want to grow citrus, you need to walk your land regularly, looking for new nests. How much land can a farmer adequately monitor? When you find a new nest, you must dig it up and find the queen, and kill her. I find a certain spiteful glee of throwing the helpless queen out into a flock of chickens, and watching them fight over her. If the colony is young enough that it has no capacity to requeen itself, you have killed the colony. If not, you will need to dig it several times to kill the colony. Sometimes, its just going to be there. In Costa Rica and Panama, I hear they use pig manure to discourage the leaf cutter ants, pouring in a foul slurry into their home.
The key is to have a diversified system whereby you can use that energy in a useful way. Without poultry, we would have little use for either leaf cutter ants or for termites. With them, they both become assets.
Industrial mentality: the solution is the problem. Have leaf cutter ants. Apply biocide. Poison soil, water, self. Support nasty earth destroying chemical company.
Permaculture mentality: The problem is the solution. Damaged soils is a problem. Natures solution is to send leaf cutter ants. Leaf cutter ants are a problem. My solution is to use them to solve another problem, what to feed our chickens.