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As the presents of Eurasian watermilfoil increases in the Northern part of Wisconsin Methods have been researched on reducing its population. One way is biological control using an increased population of the native milfoil weevil. Researchers from the University of Minnesota reported a substantial decline in the density of Eurasian watermilfoil when the weevil population reached two insects per stem.
Swift Nature Camp was pleased in the summer of 2011 to take on this project in part supported by the local lake association and the
Wisconsin Department of Natural Resources. “ This is REAL hands on Science” said Emily the Director at Swift in-charge of the little critters. Our goal was to start with a local population and create an even lager population to release back into the water. During the summer we had 10 tubs of 50 gallons each. These were home to our beginning brood of weevils. Every few weeks we fed them and hoped that they were reproducing franticly....
Swift Nature Camp,

Please pardon the amazing delay in getting you your weevil project results.  I have some preliminary results, and will send you a copy of the complete report to be filed with the DNR when that is finished (February).  

I have attached the counts from the subsamples I collected from some of the tubs during our release day.  The results were below what we expected to raise, with tubs producing only 40-200 weevils each, rather than 670 each, but please do not be disappointed.  The temperature records Emily kept gave me a lot of good information to look at.  Your temperatures in the tanks averaged 71F, which is cooler than what we planned on (77F), probably due to the shadiness of the site.  What this tells me is that your weevils' development was probably happening much slower than what we expected.  My observations of the samples also found that the stems were in poor condition, possibly also an effect of the shadiness of the site.  

But, hey, in spite of those unexpected problems (and the problem of having to hunt and search for milfoil stems!) we still released 1248 weevils to the lake, and that's nothing to sneeze at!  So thanks again for all your hard work and being part of this pilot study.  We will continue to work out the kinks in this protocol to make it truly achievable to the lake groups who need it.



Thanks!

Amy Thorstenson
Executive Director/Regional AIS Coordinator
Weevil_counts_Minong_Rearing_Tubs_Aug2011

Hi Swift Nature Camp
I asked Amy how the other groups did in their weevil rearing project for 2011.  None of the three groups had great success rates.  You saw her report on ours, Holcombe got their tanks too hot and Amy thinks the weevils developed faster than they could feed them, so they starved.  Goose Lake ended up not collected the right species of milfoil, again causing their weevils to starve.  So I guess we all learned something. 

Amy is exploring the possibility of applying for another DNR research grant to fund another program in 2012.

So that begs the question. Do you want to try and raise weevils again?  This means having to collect (and bundle) more EWM in 2012.  EWM that we are not even sure we will have.  Plus with the potential drawdown occurring sometime this year (hopefully late fall) that may have a negative impact on the weevils.  If the drawdown occurs in stages beginning in September or October we would likely be fine.  Plus we are planning a smaller EWM treatment this year so should be able to find EWM more easily.

We have the equipment, but do we have the desire?  I would again help to support it, but would want to include some money in the new grant application to do so.  Most of the money added would go to my summer technician so the costs would be much less than if I charged all my time.  He could then help collect EWM, even help bundle if necessary.

Please let me know your opinions as soon as possible.  No need to mess with it in the grant stuff, if there is no desire to try it again.  Personally, I think we should, but I am just one in a bunch that need to make that decision. 

Dave Blumer  |  Lake Scientist

DAVE 
AS YOU KNOW SWIFT NATURE CAMP IS ALWAYS WILLING TO HELP. 
PLUS, IT IS A WONDERFUL LEARNING EXPERIENCE FOR OUR CAMPERS.
Jeff Lorenz

Winter

25 Baybrook Ln.

Oak Brook, IL 60523

Phone: 630-654-8036

swiftcamp@aol.com

Camp

W7471 Ernie Swift Rd.

Minong, WI 54859

Phone: 715-466-5666

swiftcamp@aol.com