90 
Psyche 
[September 
scrub area across the thickest concentration of the mounds and 
about 150 feet farther into the pines. About 50 jars and cans 
were used placed about 5 to 10 feet apart. Several days later, as 
many as 15 G. chalyhaeus were found in a single jar, the number 
generally being highest near the greatest concentration of mounds. 
No specimens were taken in the five traps which extended outside 
the sand pine area, probably because of the density of the wiregrass 
which interfered with the movements of the beetles. 
Burrowing Habits 
Geotrupes chalyhaeus is a remarkable burrower. The burrows 
beneath the mounds or “throwups” descend practically straight 
down, and apparently offer no particular difficulties to excavation, 
but the loose sand falls into burrows so readily it is very difficult 
to reach the bottom. In early March, several burrows were ex- 
cavated to a depth below 60" below which they were lost or the sand 
caved in upon them. One burrow was excavated to a depth of 61" 
at which point it turned abruptly at right angle and ran 3" more 
before coming to an end at which a small female beetle was found 
among some pine needles and male pine cones. None of the burrows 
excavated gave any clue as to the possible larval or adult food. Old 
burrows which might have contained larval chambers could not be 
traced because they had filled with sand to within a short distance 
of the surface. 
The mounds or “throwups” are quite characteristic and easily 
identified once they have been seen. Groups of typical mounds found 
in many places seldom failed to produce at least a token specimen 
or be associated with fragments caught in spider webs beneath logs 
or rocks. In size the G. chalyhaeus “throwup” is intermediate be- 
tween that of smaller Geotrupes , Bolhoceras, etc. and the smallest 
pocket gopher mounds. A typical “throwup” is about 6" long by 
5" wide by 1^2 to 2" high. The burrow (about in diameter) 
opens under one end of this small mound and is usually loosely closed 
with a plug of damp sand. In the fresh burrows a small clump of 
roundish roll of damp sand broken into small segments indicates 
the end of the mound at which the burrows opens. Occasionally this 
roll of damp sand was seen being pushed out of the burrow, and 
once a beetle was taken by thrusting a trowel into the soil beneath 
the end of the roll. It seems very probable that the beetle excavates 
its burrow by bringing up small pellets of damp sand from the bot- 
