Ok this is worth reading. A close (very close) friend of mine wrote this and it is invaluable. He gave me permission to reprint this here.. SO I am posting the first few paragraphs then the link where you can read the rest of it. After reading this most of your pesticide questions should be answered!
Here we go
This article is written to give a very broad over view of a variety of pest control mechanisms. It shouldn't be confused with a pest control protocol. Pest control should be approached in a more organic, more evolving fashion than this rather dry list of available remedies might suggest. Pest control should be integrated with every other aspect of gardening, and care and attention should be given any time a problem arises, or a change in gardening style is made. Consider the potential ramifications of any action you take.
Think beyond the immediate, and look to see what a particular action will do in the long term. Consider carefully the true source of the problem. Insect pests will never be eradicated, so think about why they are a problem for you now. What changed that allowed them to get a foothold? How can the over all health of the plants be improved?
Carefully balancing each aspect of your garden, whether it is outside, indoors, or in a greenhouse, will result in healthier, more maintenence free plants, fewer disease and pest problems, and greater enjoyment of your hobby.
To Read the rest here is the link:http://ethnobotany.yage.net/pestcon.html