Studies in the Life Histories of Two Car- 
penter Bees of California, With 
Notes on Certain Parasites 
H. H. NININGER 
Xylocopa orpifex Smith 
Systematic observation of this species was extended over a period 
of one year, beginning September 29, 1915. 
Methods: The colony chosen for study is located on the sum- 
mit of a small mountain rising from San Dimas Canyon of the San 
Gabriels, at an altitude of about 3,500 feet, where it occupies the 
timbers of a small, deserted cabin. It required two hours of climb- 
ing to reach the cabin from the foot of the mountains. About six- 
teen trips were made at intervals during the whole autumn, winter 
and spring and one in late summer. Pieces of timber were brought 
to the laboratory from time to time, and opened. During the breed- 
ing season those occupied by eggs or larve were carefully preserved 
and prepared for daily observation by splitting the timber so as 
to expose the contents of the cells when the parts were separated, 
and again refitting the parts and holding them in place by means of 
clamps when not under observation; or, by smoothing the split sur- 
face and carefully fitting a piece of glass over the opened cells, 
which was then held in place by means of glue or other paste. In 
one case a tightly-fitting sliding glass plate was used quite success- 
fully. A dark cover of some kind was kept over the glass, except 
during observation, thus preserving as nearly as possible the natural 
conditions. As a check on the whole study a trip to the cabin was 
made at the season of their emergence and a number of cells were 
opened which seemed to corroborate all of the conclusions reached 
from the experiment, except in the case of certain parasites as noted 
below. 
Habits: Orpifex shows a decided preference for redwood as a 
medium in which to burrow. Though I found them, in one or two 
cases, using Oregon pine. It shows no inclination to choose decay- 
