Imidacloprid 75 WSB is typically mixed with 25-300 gallons of water, depending on your application per the product label. For smaller applications, you can use a similar product with the same active ingredient in a liquid form, such as Dominion 2L.
Per the Imidacloprid 75 WSB label, for trees and shrubs, you will use 1.6 oz. (1 packet) per 24 to 48 inches of cumulative trunk diameter. Uniformly apply the dosage in no less than 10 gallons of water per 1000 square feet as a drench around the base of the tree directed to the root zone. Remove plastic or any other barrier that will stop solution from reaching the root zone. Please see the label for complete application instructions. Be sure to apply this product only on fruit trees listed on the product label.