Talus 70DF Insect Growth Regulator can be used on ornamentals in outdoor nurseries but it is not labeled to kill any pests, it is used to help disrupt the life cycle of the labeled pests. The best way to prevent mealybugs is to keep your plants healthy, we recommend consulting with your local nursery, or extension office for tips on growing healthy succulents - which may include getting a soil analysis done to help you use the right fertilizers to promote healthy growth. We don't believe that the Orcon Cryptolaemus you are using would be affected by Talus 70DF IGR, and there is no information regarding that on the label, we recommend reaching out to the manufacturer at 1-800-419-7779.
70DF Insect Growth Regulator should be used at a rate of 14 oz per acre for scales. The amount of water depends on how much water it takes to treat an acre.