EnviroScience, Inc.
Letter Subject: Milfoil Weevil information
Date: Fri, 12 Dec 2008 12:52:44 -0700
Dear Ralph,
It was nice talking with you this afternoon. Below please find a letter from Marty Hilovsky, EnviroScience president.
Thank you for your interest in our program for controlling Eurasian watermilfoil using native weevils. Please find some general information and a few questions that may help determine whether the milfoil weevil, a type of beetle, may be a good option for you.
This Eurasian watermilfoil (EWM) management program is named the MiddFoil® process. Developed by Dr. Sallie Sheldon and Middlebury College (VT), MiddFoil® utilizes an insect that specifically feeds on EWM. This insect, a native weevil, is intentionally introduced into the water body where EWM is a problem. Extensive field trials show that the weevil is a very effective control agent. Depending on the initial density applied, the weevils take from three to five years to permanently stabilize EWM below problematic levels. Most importantly, the MiddFoil® process is environmentally safe; the weevil does not damage native plants or animals. As EWM decreases in the treated lake, the weevil population gradually declines to a self-sustaining level.
Under an exclusive licensing agreement with Dr. Sheldon and Middlebury College, EnviroScience, Inc. is pleased to make the MiddFoil® process available to resource managers and the general public. EnviroScience is expert in biomonitoring and lake management services. We maintain one of the largest aquatic and ecological survey departments in the Midwest. In addition to a large in-house staff of aquatic ecologists, we are closely allied with a number of universities and nationally recognized experts. We draw on these resources as needed to support projects of virtually any size or complexity. Our combination of solid experience and state-of-the art equipment ensures that our projects are done right and completed on time.
With regard to cost, pricing is difficult to quickly estimate because there is no single formula to tell us how many weevils are needed to control the EWM in a given water body. Variables that can influence how many weevils we use in a given project include:
- the size of your lake;
- how many acres of EWM you have;
- the density of the EWM;
- when the weevils are stocked (early summer is best because they produce several generations);
- how quickly you want control - the more you put in the faster they will effect lake-wide control.
With most lakes we incorporate pre- and post- application monitoring surveys in our projects. Under this program we perform initial baseline surveys at the time of stocking and then survey again at the end of both the first and second seasons to make sure the weevils are reproducing and spreading around the lake as expected. The surveys allow us to chart our progress and provide the association with detailed progress reports. The survey component also includes fees associated with stocking the weevils and generally costs between $4,000 and $5,000 for a single stocking program and for most lakes within 400 miles of our office. In addition, we add the cost of the weevils which are sold in units of 1,000 at $1,200 per unit. We do not install less than 2,000 to 3,000 in any one area of the lake. Most of our clients will place three or four thousand in several locations around the lake. In most cases, it probably does not make sense to spend less on the weevils than you do on the survey, so our smallest lake projects are generally at least $10,000 and have gone up to $150,000.
The difference, aside from cost, between putting in a total of several thousand weevils and the maximum rate of 2,000 to 3,000 per acre of weed bed, is the length of time necessary to get lake-wide control. Stocking at the maximum rate can produce relatively rapid results - about two years for lake-wide control of EWM. Stocking weevils at lower densities will produce more gradual results.
In special circumstances and with ponds and very small lakes we work with landowners to streamline the process and make it more affordable by allowing them to apply the insects and dispense with the monitoring component. This approach has both pros and cons and is generally not recommended for larger, more complex situations. In any case, the program is quite flexible and can accommodate most lake budgets.
The MiddFoil® process can be easily integrated with other types of control programs. Many of our clients use harvesting or herbicides in high priority areas like beaches and marinas while the weevils are becoming established in other parts of the lake. This is another reason why we build the survey component into most of our projects. The surveys enable us to inform you how the weevils are increasing and spreading so that you can make good decisions regarding where to treat with alternate control measures during the first couple of years while the weevils are becoming established and spreading out.
If your association has a fairly steady funding base from year to year, I would also encourage you to consider a program which would allow for stocking over a two-year period. Data collected over the past six years indicate that multi-year stocking programs provide a number of advantages over a single, larger stocking event.
If you believe there is sufficient interest in the program for this coming summer, we would be glad to arrange a meeting with you to answer any questions you may have.
Sincerely,
Martin Hilovsky President EnviroScience, Inc.
