Saturday, November 9, 2019

Dermestids in a Skull

Dermestid beetle larvae
So, reaching for a new height in the ridiculous pursuit of weird tiny insect life, I present you with dermestid beetle larvae found in a deer skull.  We have taken this skull to WOLF the last 3 years while it spent the rest of the time in a bag upstairs at the creek house.  When Barb took it out at WOLF some powder fell out of the base of the skull and a student noticed that something tiny was moving.  Magnification with a digital microscope showed cute fuzzy larvae.

Chris Barnhart identified the photograph as Dermestid beetle larvae.  There are over 500 species of beetles in the Dermestidae family with a variety of lifestyles.  Most of the larvae are scavengers, living on dry plant and animal matter, sometimes with very specific tastes.  Dermestid larvae are profoundly covered with varying lengths of hairs (setae) that gave them a distinctive appearance. The larvae are generally dark brown to black and go through complete metamorphosis.  Adults are less commonly found and feed on flowers and shrubs.

Ventral view of exuvia within their dried frass
Some dermestids are famous for their forensic connections, living on dead animals and giving clues of the time of death.  They are available on line to use in cleaning skulls and bones of animals in laboratories for the study of anatomy.  Our larvae had been surviving in a deer skull for several years.  Fortunately they like to eat dry dead stuff.

Home on the frass
Above you can see the results of life in a deer skull, lots of larvae moving around in their world of frass and molted skins (exuvia).  This prompted me to make  this video for a closer look.  For more information on the value and risks of using Dermestids to clean bones, watch this educational PBS video showing the beetles at work.
More species are discussed at