178 
Cleaning Skulls and Bones with Aid of Dermeslid Beetles 
The various species of the genus Dermestes, known popularly as bacon 
beetle, buffalo bug, etc., have long been rated as destructive pests that 
attack drying hides, pelts, dried meats, and other animal products, as 
well as zoological specimens of all kinds that are not thoroughly poisoned. 
Collectors have found in the past that certain insect larvae will clean the 
animal matter from unpoisoned bones, and if the bones are exposed too 
long the ligaments are eaten away, small bones fall apart, and becoming 
mixed are difficult to sort out. C. D. Bunker of the University of Kansas 
is generally credited with being the originator and pioneer of a practical 
method of cleaning bones with the aid of insects, and the method has 
been used successfully by A. Brazier Howell in the Smithsonian Institu- 
tion, Remington Kellogg and E. R. Kalmback in the U.S. Biological Survey, 
Harry C. Raven in the American Museum of Natural History, E. Raymond 
Hall in the Museum of Vertebrate Zoology, and Clifford Hope in the Royal 
Ontario Museum of Zoology at Toronto. 
Messrs. Hall and Ward (1933, pages 359-360) describe the method 
now used at Berkeley, California, employing dermestid beetles of the species 
Dermestes vulpinus. A sufficient number to start a colony may be found 
in decaying carcasses of vertebrates, especially in those where some or 
all of the meat has “dried up”. A fair number of adult beetles is required 
in a working colony for reproductive purposes, but the growing larvse 
consume the greater amount of food and are the most useful as bone 
cleaners. In the Life Sciences Building at Berkeley, a “bug-proof” room 
8 by 10 feet is warmed by a steam radiator regulated by a thermostat 
so as to maintain a constant temperature of 84° Fahrenheit. A pan 
of water placed on the radiator provides the necessary humidity. The 
walls have steel shelving that supports wooden boxes 3 feet long, 18 inches 
wide, and 1 foot deep, in which the beetles are reared and allowed to 
work. A strip of tin 3 inches wide, laid around the inside of each box 
at its top, keeps the “bugs” more or less confined. A few T adult beetles are 
put in one of the boxes with a partly dried carcass and left for about a 
month. When a large number of larvae are concentrated in a small space, 
a diminishing food supply forces them to work on any new material 
introduced. The hard dry specimens received from the field are placed 
one layer deep on layers of cotton in shallow cardboard boxes with another 
layer of cotton covering them. These cardboard boxes are then placed 
in the boxes containing the “bugs”. The “bugs” will usually clean small 
skulls in from 24 to 48 hours, depending upon the number of “bugs” and 
the amount of food remaining in the carcass used for nursery purposes. 
After removing the skulls from the “bug-room” the lower jaw of each 
is disarticulated and the cranium, jaws, and tag are put in a vial. 
Ammonia, concentrated, 26 per cent is added, and the vial corked and 
allowed to stand for 12 hours. The ammonia will loosen any pieces of 
meat or cartilage overlooked by the “bugs” and will also remove excess 
grease in the bone. The ammonia is then replaced by water and the 
skull allowed to soak 24 nr more hours, depending on its size. After 
pouring off the water the skull is washed in a fine stream of warm water 
with a cross current of compressed air. This can be done in a 
small sink, preferably set in a work table. Above this, connections 
to hot and cold water lines empty through an outlet to permit 
