When using Bt for wax moths, what is the best time to use it? According to the literature, the timing is vital because once the product is added to water and applied to the target plants, the usable life is very short. If the larvae is not feeding, it will not work. Do you wait until you see wax moth larvae or use it on a set schedule? I am currently seeing plenty of wax moth flying around the stored frames and am seeing them under the top covers when I lift them off for inspections. It could be that when the products are used in the fields on plants that the sunlight and weather shortens the usable life of the products. Inside of a storage area that is dark will not have those issues.