Dermestid beetles

Yesterday, I brought my students to the Field museum to visit their in-house designers and learn what they do in-house environment versus a design studio. Jean Cattel, their design manager was a gracious host and showed all that they do as the Field Museums in-house design group, from ads, to exhibits to print maps and all things visual in the museum.

Then we had a brief tour of their replication/model shop where they create many of the actual exhibits and items used in the exhibits.

Finally, we were treated to a truly behind the scenes adventure at the museum. . .the specimen room. This is where they prepare animals for display either in skeletal form or as a fully stuffed/modeled animal. We were greeted by a man holding a gray owl up by its next and stripping its feathers, this was to be used as a skeleton. But how does one get all the flesh and tissue off the bones?

Welcome to the Dermestid Beetle Room. A rather odiforous room full of aquarium tanks and dermestid beetles feasting on pieces of skeleton. Here is what dermestid beetles are and do.

Dermestid beetles are members of the insect family Dermestidae, commonly called carpet beetles, hide beetles, and larder beetles among other names. The particular species you have received is Dermestes maculatus. D. maculatus lives on dead, dry-moist animal matter which makes them the bane of taxidermists and museum curators. Fortunately, this feeding characteristic is great for cleaning bones. At each stage of the beetles life they eat different materials. When they are small/just hatched they get inside the smallest of bird bones and clean out the marrow. As they grow they clean other areas.

The adult prefers to lay eggs on slightly moist material whereas the larvae thrive on dry flesh and connective tissue. Eggs hatch in 3-4 days and the larvae go through an average of 7 molts or instars, reaching pupa stage in about 45 days. The pupal stage is contained within the last larval skin. Adults have a fertile period of around 2 months and live up to 5 months.

As with all insects, the life cycle is temperature dependent. Dermestids are sluggish below 70 degrees and adults cannot fly below 80-85 degrees which is good if you open their container at room temperature  – they won’t fly away. I use a reptile thermostat-controlled heat emitter and maintain a robust colony at 90 degrees.

In the end the one thing the students took away from the Field trip? The speciment room and the beetles!