• weevils are sold in units of 1,000 
• no less than two units can be stocked in any single location (most projects involve a minimum of 6-10 units) 
• because weevils produce 3 or 4 generations per summer, stocking early in the season is advisable 
• there are no hard and fast rules on how many units are required per acre of weed bed;  on an individual basis, EnviroScience representatives custom-design programs which effectively strike a balance between the need for relatively rapid control and reasonable cost.

Each MiddFoil® project involves a monitoring component designed to establish baseline conditions and document progress over at least two growing seasons. This monitoring portion involves:

• an initial survey of the milfoil beds to be stocked (stem density counts, determination of indigenous weevil populations, if applicable).
• baseline site marking using differential GPS technology
• initial stocking by EnviroScience personnel
• written progress reports

At a minimum, follow-up surveys are conducted at the end of the first and second growing seasons to ensure that weevil populations are increasing and spreading as expected. Follow-up surveys in subsequent years may be advisable, particularly where MiddFoil® is being integrated with other control methods such as harvesting or herbicide application. In such cases, the surveys provide information needed to make good decisions on where to expand or create additional "no harvest" or "no spray" zones as weevil populations grow and expand out from the initial stocking areas.