You will never be able to pinpoint the source of your spider mite problem....these pests are ubiquitous. Be sure to comment on the mite problem to someone at the nursery! May I ask what your 'typical remedies' have been? Maybe we can all put our heads together to help you manage the population. Spider mite numbers seem to explode when plants are over fertilized with nitrogen, are stressed by heat and insufficient water, or are growing in an inhospitable soil. The population will also dramatically increase after the use of such broad spectrum pesticides as Sevin, malathion, pyrethrins and others. This post was edited by rhizo_1 on Sat, Mar 30, 13 at 22:18

Suspect your 'cotton balls' are mealybugs. Dabbing them, or wiping them off gently with a dilute water/alcohol swab should take care of the problem. If you have a shower, or can take your ficus outside, spray it with water. It will help wash away spider mites. They do seem to burst forth in hot/dry situations, but just keeping them humid might not be the panacea it's purported to be. Spider mites aren't always red, btw and so tiny you can barely see them with the naked eye. The tiny grey specks on the ivy were likely immature mealy bug. They and spider mites are real nuisances on ivies. You may wish to spring for a bottle or real insecticidal soap, instead of making up your own brew.

Just ordered No Spider Mites, 32 oz for $39, no tax and free shipping. Its a bit pricy, but will last me two seasons. I read several reviews and everyone swears by this product. it works as in it kills the eggs. I want to eat eggplants from all my 8 plants, 4 varities. This is also helpful for tomato plants. I didnt realize that I posted it in tomato pests. LOL.

I had them once on a ever green and before I notice a 2 ft area was dead. I asked a nursery man about it and he said you can't see spider mites. He said to put a white sheet of paper under the area and shake the plant, then rub your fingers across the paper. If there are blood smears they are spider mites.