You see, one of the more annoying characteristics of HWA is that they can produce two generations of offspring in one year. A fall, sistens generation and the spring, progrediens generation. The predator beetles that we are so fond of are only active during the fall, which means the adelgids have an entire season to feed and reproduce without the presence of a predator.
Well, we aim to end that with the introduction of silver flies!
I will spare you the lengthy details on permitting and logistics of such an experiment. Just know that this involves a whole lot of people at several state and federal agencies making sure all that we do is upright and in-line. We have an amazing cooperator in the Pacific Northwest rearing flies and sending them to us for our experiment. The big idea in all of this is to establish biological control agents that are able to eat, harass, harangue, or otherwise subjugate HWA, so our hemlock trees can live long happy lives with only minimal damage from the pesky adelgid.
This years experiment is the largest yet with field sites from South Carolina to New York including Great Smoky Mountains National Park in Tennessee. We are hoping for more positive results!
We are releasing flies into sleeve cages on infested branches at our field sites, then returning at predetermined intervals to collect the samples in order to find out how well flies are feeding and reproducing.
"Now here we go dropping science, dropping it all over..."
-Beastie Boys from "The Sounds of Science"