History and Habits of Pityogenes. 43 
change to the adult condition occurred May 2d, and betore the 
following morning the body covering had hardened suffi- 
ciently for the young beetle to begin burrowing. These and 
other observations established the period of pupal life in the 
laboratory where conditions are favorable, at five or six days. 
No definite data regarding the length of pupal existence under 
outdoor conditions was made, but judging from the similarity 
of the larval period under laboratory condition and in nature, 
it would not differ greatly from this. 
The pupae vary considerably in size as do the full grown 
larvae and the adults. Alcoholic specimens measured show 
a variation in length of from 1.76 mm. to 2.25 mm., and a 
variation in the width through the prothorax of from .680 
mm. to .910 mm. Aside from the difference in color pre- 
viously mentioned there is a very noticeable difference in 
appearance between the newly formed pupa and one four or 
five days old. The most striking difference is in the wings. 
In the young pupa these are snowy white in color and both 
elytra and true wings extend backward from the thorax at 
an angle of from thirty to forty-five degrees to the abdomen, 
while in the older pupae they lie close to the sides of the 
body leaving the dorsal part of the abdomen uncovered, while 
the metathoracic wings, which are longer, nearly meet in the 
mid-ventral line. 
Tur Youne Aputts.—On emerging from the pupal stage, 
the prevailing color of the young adult might be described 
as cream color or a very light tan. However, even at this 
time the tips of the mandibles are nearly black, while the 
body of the mandibles, the joints of the legs, the rugosities 
on the prothorax and the spines on the tibia and on the 
declivity of the elytra are light brown. The eyes also appear 
to be of a rather dark brown, but on examination with a 
microscope, it is readily seen that the color here is not due to 
pigments in the superficial structure, but to the pigment 
isolating the various omatidia making up the compound eye. 
The callow insect begins feeding almost immediately after 
emerging and its color becomes progressively darker, until 
at the end of from five to seven days it has usually acquired 
the appearance of the full fledged adult. 
