Fast forward one year to 2013. The Back Lake area was abandoned as a release site due to it inaccessibility during low lake levels. That said, this area has been checked out this year to see if the weevils released last year remained in the area and if they were having any impact on giant salvinia.
The short answers to those questions are Yes and Yes! Photos taken at this site show considerable damage to the giant salvinia at this site and a decent amount of open water present as well. We will be going out to this site in the next few weeks to collect samples so the weevil density can be counted and will also survey the surrounding area to see if any other weevil damage can be found.
|Weevil damage at the 2012 weevil release site in Back Lake. No weevils were released at this location in 2013.|
This find is really encouraging as it shows that the weevils released in earlier years survived the winter in large enough numbers to have a noticeable impact on giant salvinia. While this is only a small success, it is still a success!