How do I know the Laricobius biological control predator won’t move on to native insects once HWA is gone?

Although there have been some biological control failures, there are dozens of other successes. The Laricobius beetles are one of these. These beetles were subjected to approximately 10 years of studying before release, and it was determined that they are obligate feeders of HWA. This means that we see the Laricobius populations disappearing once the HWA is gone–while they may be able to feed on other adelgid species, they are dependent on HWA in order to reproduce, and thus cannot survive without them.