Post by livingplanet3 on Jun 4, 2021 20:44:06 GMT -8
Has anyone here ever actually had dermestids (that is, Carpet Beetles [Anthrenus spp.]) attack dried insect specimens that were stored in plastic zipper storage bags - the extra strength ones (1-gallon freezer bags, with double-seal)? It seems I once read that really determined dermestids can actually chew through zipper bags, but I've been storing specimens in them for many years, and haven't had a single case of dermestids ever getting through them. These beetles are definitely present in my house, but in my experience at least, keeping specimens in zipper freezer bags (even without enclosing any kind of chemical protectant) appears to make them impervious to attack. Or, maybe I've just been lucky?
I use Zip lock Storage Bag after I paper specimens in the field. Once I return home I separate the "Mount First" specimens. The remaining envelopes I place in Seal Tight Containers and place them in a freezer. By the following Spring I have sorted out the keepers and have spread/mounted most of the specimens. However, I always manage to accumulate more specimens in my freezers, yes plural: Freezers, every year.
Post by livingplanet3 on Jun 5, 2021 8:40:29 GMT -8
Thanks for the comments. With as many of these bags as I've used, and for as many years as I've been using them, it seems that statistically, I would have had dermestids get through them by now at least once, if they were capable of doing so.
In the museum where I work, for papered leps heading into storage, we first run them through a freezer for a couple of weeks. The freezers cycle from about 32F (if the doors get opened) during the day to -22F overnight. It's a flash freezer, that drops very quickly, helping prevent dermestids from acclimating to the dropping temperature and surviving the freezing. This also helps to kill eggs present - although this cannot be counted on as some may make it through. Specimens are frozen in whatever container they came in, be it plastic shoeboxes, cardboard boxes, drawers or Schmidt boxes. Then they're taken out of the freezer and once they return to room temp we transfer them into Ziploc freezer bags. These are then placed in Schmidt boxes or drawers, and then run through the freezer once more before storage in the collection. These are again frozen routinely every year to year and a half, as a prophylactic measure.
In my experience, no specimens treated in this manner ever became infested while in Ziplocs.