Jul 31, 2020 - 06:26 AM
Be sure they are actually dead before you toss them out. Any time a colony takes a sudden plunge in productivity you may suspect a "mass pupation" You can look through your colony bedding for pupae and "frozen" adolescent larvae that are curled up in a comma shape and not moving -- these are not dead, they are prepupal larvae. If you find a lot of these, you've got a mass pupation going on. Mass pupations are triggered by a change in the environment (usually by a sudden plentiful food source, but other factors can cause it as well).
Dermestid beetles and larvae are extremely hardy; it is rare that your colonies die at once. If you'd like to send us a photo of your setup and let us know how you've been caring for them, we'd love to help!