172 
Psyche 
[September 
with studies of the moths associated with it and have never seen 
termites in the stalks elsewhere” (Powell, 1966, in litt .) . A col- 
lection of nymphs was taken “in Yucca” by C. C. Lamb at Santo 
Domingo Landing, Baja California del Sur (Light, 1929). The 
fibrous or pithy tissues of yuccas would seem to be a rather unusual 
situation for the nest of a dry-wood termite. 
The haphazard system of tunnels and chambers made by a colony 
of approximately 3000 individuals is shown in the longitudinal 
section of a dead palo verde in figure 4 B. In this and in one other 
standing palo verde, the colony had penetrated wood a few inches 
below ground level. The rough-surfaced galleries of Pterotermes 
could not be mistaken for those of any other termite in the desert. 
Although in a quite different environment, the workings of a large 
colony are nearly as large and extensive as those of Zootermopsis 
(Nutting, 1965). Galleries are generally driven in sound wood, 
although many palo verdes have been found where 50 to 75 percent 
of the wood has been previously tunneled by wood-boring beetle 
larvae. In this case the termites work through the tightly packed 
sawdust and even use the cleared tunnels for short distances. Since 
the soldier head is approximately 4 mm. wide and the abdomen of a 
large nymph may be nearly 5 mm. in diameter, the tunnels and access 
holes between chambers seldom measure less than 3X5 mm. Active 
galleries are nearly free of fecal spottings and pellets, but large dumps 
of loose pellets are found in abandoned chambers. In a caged palo 
verde colony, large quantities of fecal pellets were dumped from an 
old borer exit a few inches from the ground. Considerable use is 
made of semi-liquid fecal material in walling off old galleries and 
in plugging lateral tunnels made by borers to the outside. 
Colonizing flights. Previous flight records from Arizona had 
suggested that Pterotermes flies on a relatively few nights during 
late July and August. Alates from Baja California were taken in 
light traps in late August and early September by Werner and Rad- 
ford (Table 1). Apparently the only observations on a flight in 
nature were made by the author on the night of August 7, 1963, in 
the Tucson Mts. A lantern was operated from dusk until midnight, 
and hetween 2235 and 2330 hrs. four males and four females flew 
rapidly in to the light on the ground. It was impossible to tell from 
what altitude or direction they had come. They were very active 
under the light but did not leave. The evening was quiet and nearly 
cloudless with the temperature between 22 and 23°C. The moon 
had risen about an hour before the flight and was just past full. 
As part of a long-term study, flight and meteorological data were 
