My brother was involved in trialing a new fruit fly chemical. The chemical company bought a row of fruit trees on his place and sprayed it for three years at different rates and did test after test. Must have cost a fortune. The guy was telling him they did the tests on stonefruit to get it registered. He said just to add another type of fruit would cost around $100 000 each time. They will add them over the years defending on the success of the chemical. I wanted to set up a planting of jujubes, but as the industry is so small not one company will put jujubes on their labels due to the cost of testing, which then makes it illegal to use. Similar to worming is mite sprays. They become resistant so fast the companies are reluctant to put work into new ones. This is where you need to look into alternatives. With mites it is predatory mites. With worming you can do egg counting or take samples to someone who does it. Only worm when egg numbers are high. Most people waist money worming when it is not needed at all. Learn the life cycle and rotate your paddocks, keep your copper levels sustained and do egg counting and you will be surprised how little worming you actually need to do.