Ant "harvesting" sugar from an aphid.
The idea for this great tip comes from Steve Sysko in the Sept/Oct issue of Countryside and Small Stock Journal:
Ants climbing in and around your plants are common. Most of the time, this is not a bad thing at all. Sometimes, this can even be a good thing.
I recently heard of how one gardener believes that the black ants in his garden have taken care of his squash vine borer pests. In his previous gardens in another part of the U.S., he had a lot of damage from squash vine borers, and he knew the telltale signs of infestation and damage. However, upon moving to his new location and starting a garden, he has not had this issue. He has seen the characteristic burrow in the base of the vine, but the burrow was shallow and had black ants going in and out. His thought is that these black ants find, kill, and eat the young larvae before it does any damage. Hard to know if that is true, but if it is, this is pretty amazing.
However, you need to pay attention when you see ants climbing around on your fruit trees. A few here and there are no problem, but if you see a lot, you may need to be concerned. Check closely at the shoots and small leaves for aphids.
Ant defending his aphid herd from a ladybug.
Ants and aphids can develop a symbiotic relationship. The aphids excrete a sweet substance that the ants eat, and the ants will protect the aphids from predators. It is almost like a bunch of dairymen caring and protecting their herds of dairy cattle.
If this is happening in your fruit trees, significant reduction in growth and fruit yield can result. If you can stop the ants from protecting the aphids, which love to eat your fruit trees, then this allows the natural predators (ladybugs, lacewings, etc.) to kill the aphids.
How can you do this without chemicals, toxins, and poisons? Duct Tape!
Wrap the base of the tree (about 3-4 feet off the ground) with duct tape, sticky side out, for about 8-10 inches in height. You may need to change the duct tape every few days if either the duct tape dries out (and becomes less sticky), or if the ants that get stuck create a living bridge for the remaining ants to cross over. Steve comments that it is easier to place another layer of duct tape over the previous one instead of removing the first and adding the second. Eventually, the ants give up and move elsewhere. If you had ant and aphid issues previously, you can set up duct tape protection on your trees in the spring before the ants emerge. This prevents them from getting established, and hopefully does that same with your aphids. Steve comments that after doing this for a few seasons, the ants never returned.
I love this idea! A great Permaculture Tip!