Living in Texas, I don't know of a permanent solution other than living with them, or constantly using a bait or other ant killer. Last year, just about every one of my containers had ants. As a short term solution, I would combine two of the methods listed above. Bare-root the tree and spray the ants with a sharp stream of water. You may damage a few roots, but your tree won't miss them. Afterwards, soak the root mass in a bucket of water. The second step will flush out the ants (and more specifically, the queen, if they have bored into the trunk under the basal flare (yes, they sometimes do that). You will want to soak for a couple of hours. To prevent the ants from infesting your containers to begin with, you can set your container on something and treat whatever it's sitting on. For example, my containers were on two strips of treated wood to keep them off the ground. One could soak the wood in an ant killer, or smear it with Tanglefoot or petroleum jelly to prevent the ants from crossing into the container. In order for something like this to be successful,however, you would have to make sure the top of the tree doesn't touch anything else and that grass around the container doesn't come in contact with it. Those ants will find anything they can to use as a bridge. Or you would have to effectively control the entire yard. Whatever you do... do NOT plunge your hand into the growing medium without checking for ants. It's been two weeks since I forgot that rule and my right hand is still swollen. ~james

To expand what ken said, the aphids secretes a sweet substance that the ants feed on, so as Ken says ...get rid of the aphids and you will get rid of the ants by spraying them with water or using insecticidal soap..... As for the "critter in the spit".....it is a spittle bug that is sucking the plant juices from your plant and is protected by the frothy foam......best way to rid them is to wash them off with water.... Here is a link that might be useful: spittle bug

This is a recipe that was given by the head groundskeeper of the Parliament Buildings in Ottawa, Ontario, Canada. It uses somewhat what Daisy referred to...only use boric acid....bought at any drugstore. To two cups (450 millilitres) of boiling water, add two teaspoons of boric acid, and two cups (450 grams) of granulated sugar. (I know how to measure metric...but I'm still not used to writing about it) Stir to dissolve sugar fully. Let cool. Then, into a small container....much like a margarine container, you put holes at the sides at the bottom to let the ants enter. Into the container you place about 6 cotton balls (also bought at the drugstore) after soaking them in the solution. Put the lid on to prevent other insects such as bees from entering. Then place the containers where you see the trails or mounds of ants. The idea is for the sugar to be the come-on...the boric acid the killer. The worker ant takes the liquid back to the nest and feeds it, like a good ant will, to Queenie.. she gets a terrible tummy ache....and the colony dies with her. Any pointed shoe can kill an ant in the corner...it takes a wise wearer to know how to kill hundreds without putting your foot down. Anyway, its supposed to work on the feared RED ANTS of southern U.S. so I cant see where an Ausie ant's stomach is any less upsetting. Now there are a few more suggestions and they are talked about widely whether they, in fact, work or not. Grits....that southern U.S. morning food.....tastes like bland cream of wheat... well, this stuff expands when moistened and figuring an ant's stomach has such acid, it suggests when an ant eats the grits, the stuff explodes inside its stomach. Another one....make the ant cross through some baking soda. He gets it on his feet (or whatever an ant calls his feet), some of it gets into his mouth...and the old story.... when baking soda gets wet it turns into carbon dioxide.... GAS that is....and since an ant cant burp, cant flatulate, he goes all to pieces. Anyway, that's the theory.

Citrus fruits compete against each other for the trees available energy (Food). The fruitlets that loose out are discarded by the tree. A few will stick to the branch die and shrivel turning black. Of all the fruit producing flowers on a citrus tree, only about 1 to 2 percent will produce fruit to maturity.