Protoplasmic poisons like malathion and acephate act by interfering with the metabolic processes of insects and are effective against most crawling and sucking pests. General poisons like chlorpyrifos ...

You have to apply the insecticides before thrips enter unopened rose buds. If you want to buy an insecticide to control thrips, consider products with permethrin, lambda cyhalothrin, cyfluthrin, ...