1966] 
Nutting — Dry-wood termite 
175 
ness, from two hours or more after sunset until three-quarters of an 
hour or more before sunrise. A complete account of these flight 
studies on Pterotermes, including behavior of the alates, will appear 
as part of a separate series on the colonizing flights and associated 
activities of termites. 
Table 2. Composition of five colonies of Pterotermes occidentis from 
Arizona. It was impossible to determine whether colonies No. 4 and 5 were 
fragments of a single colony in the same log, or whether No. 3 was actually 
made up of two colonies in the same tree. K and Q represent primary 
reproductives ; Rep., replacement reproductives. 
No. 
Nymphs 
Soldiers 
Oracle Jet., 8 mi. S. 
Reproductives 
Eggs 
1 
721 
37 
K + Q 
79 
2 
2867 
42 
K + Q 
3 
4055 
82 
Alamo Wash 
Q + 2 Rep. 
ca. 30 
4 
59 i 
21 
2 Rep. 
5 
1082 
28 
1 Rep. 
Founding of the colony. About 30 incipient colonies have 
been collected in dead palo verdes in the vicinity of Tucson. Several 
were found 6 to 10 feet above the ground. Observations on these 
and on post-flight behavior of caged alates indicate that the alates 
use cracks and borer exits as primary points of attack. The initial 
chamber, or copularium, (Fig. 4 A) is usually hollowed out of sound 
wood less than one inch from the surface. A few captive pairs have 
been maintained in petri dishes containing a slice of wood on a layer 
of plaster of Paris, with a few drops of water occasionally added 
to the wood or plaster. Shrunken reproductives and nymphs become 
excited in the presence of moisture and will readily drink to repletion 
from free droplets or a cotton wick. However, laboratory colonies 
may die within two weeks where free moisture or even moderate 
humidities prevail. The pairs were kept in a study from September 
through May where temperatures varied from 13 to 2 J°C. 
Explanation of Plate 9 
Figure 2. Scene in the foothills of the Santa Catalina Mts. north of 
Tucson, Arizona. To the left is the ribbed, woody skeleton of a saguaro 
cactus, Cereus giganteus ; to the right, a palo verde tree, Cercidium micro- 
phyllum. Pterotermes has been found in these skeletons and in the dead 
wood of Cercidium. 
Figure 3. Cercidium — Cereus association on the western slopes of the 
Tucson Mts. west of Tucson, Arizona. Pterotermes has been taken in this 
area which is typical of the Sonoran Desert in southern Arizona. Photo- 
graph by Peter J. Mehringer, Jr. 
