[Nhcoll-l] dermestid colony slowing down

[Thomas Labedz]

Nick
Is the colony young or not had a chance to have age classes evenly distributed? After a colony has all age classes (eggs, various larval instars, adults) evenly distributed the colony works at a consistent pace. In my experience, a lack of greasy bones in the colony means the first instars (smallest larva) have difficulty getting enough to eat. I think of that age larvae as “grease suckers”. That can lead to a missing generation down the line, slowing the colony’s ability to work well. I’ll put greasy bones of a roast chicken, turkey, pork chop bone, ham bone, etc. in as a “nursery” for those young ones.
Are there locations for pupae to develop? I scatter bits of corrugated cardboard (bigger corrugations) in the colony as places for pupation.
Is the colony contained and aging? My colony is contained in a plexiglass terrarium. When the level of shed larval skins and dermestid poo builds to a certain point it begins to self-compost and the dermestids become more interested in finding a way out than doing the work. Then it is time to restart the colony.
Check for mites. Usually indicated by adults with elytra held out of normal position. Can also be indicated by masses of the little beasts looking like dust moving across surfaces.
Check for spiders or other predators impacting the beetle colony.
Check for fungus or mold resulting from too much moisture.
Check for the tissue being too dry (rock hard). Moisten a little until they can chomp it.
Were the bison remains treated in some way prior to being added to the colony? Example, someone spritzing the dried skull with insecticide to prevent or stop an insect infestation before it got to you. I had one idiot do that and it killed my colony overnight.
Were the bison treated by a veterinarian in some way prior to death? I’ve had specimens where the euthanizing drug persisted in tissue and the beetles avoided that tissue.
Had the tissue rotted prior to being dried? Beetles will avoid tissue that had been rotten.
Good luck!
Thomas
PS - I’ll be visiting Alberta (Calgary) in a couple of weeks. Would love to pop over to see your operation but won’t have time on this trip.

Thomas E. Labedz (Mr.), Collections Manager
Division of Zoology and Division of Botany
University of Nebraska State Museum
Morrill Hall
645 North 14th Street
Lincoln, NE 68588-0338
402/472-8366
tlabedz1 at unl.edu<mailto:tlabedz1 at unl.edu>   www.museum.unl.edu<http://www.museum.unl.edu>


From: Nhcoll-l <nhcoll-l-bounces at mailman.yale.edu> On Behalf Of Nick Cairns
Sent: Friday, July 21, 2023 9:39 AM
To: nhcoll-l at mailman.yale.edu
Subject: [Nhcoll-l] dermestid colony slowing down

Non-NU Email
________________________________
Morning everyone,
We're having an issue with our dermestid colony. Despite seemingly good temperature and humidity the colony is failing to process the modest amounts of material we are putting in with them. They've mostly been stripping bison mandibles for the last few months but seems to be consistently slowing down. We've tried warming them up and subdividing them but it's still slow.  Any advice or experience with this would be greatly appreciated.
Best,
Nick

Non-avian curator
Royal Alberta Museum
Edmonton Alberta, Canada
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