1966 ] 
Nutting — Dry-wood ter?nite 
173 
collected from June through September, 1965, in Tucson, Arizona. 
A six-foot section of dead palo verde, containing what was probably 
a single colony of Pterotermes , was set in a field cage (6x12x6 feet) 
of 20-mesh Saran screen. Observations were made at various times 
nearly every night as well as for the entire period from dusk to 
dawn on a few other nights. A small black light trap was run each 
night in a corner of the cage so that there was reasonable assurance 
that practically all alates were captured. 
The colony staged 40 separate flights during the 43 days beginning 
July 22 and ending Sept. 2. The smallest flight consisted of one 
alate, the largest 199, and roughly equal numbers of males and 
females were trapped. Twenty-five alates were later found to have 
escaped the trap and established themselves in cells within the same 
tree from which they flew. These plus those from the trap gave a 
total of 1688 alates produced by the colony. Nearly six months 
later the entire colony was removed from the tree and found to 
contain 4055 nymphs (Table 2, No. 3). Assuming that there were 
approximately 5600 nymphs in the colony during the spring of 1965 
(number of nymphs produced since then not counted, but probably 
less than 200), this means that an impressive 30 percent of them 
developed into alates. It should be stated that it was impossible to 
determine whether this was actually a single colony or perhaps two, 
since a queen and a pair of replacement reproductives were found 
widely separated in the tree. 
Although accompanying data have not yet been analyzed, a few 
generalizations may be made relating weather conditions to the flight 
season and the daily flight periods. The flight season began about 
three weeks after the highest weekly mean temperature of the year 
(30.5°C) was reached and continued for approximately six weeks 
with weekly means between 26.8 and 29.5 °C. Individual flight 
periods took place with nighttime temperatures ranging from ap- 
proximately 19 to 29°C. The flight season occurred while some of 
the highest weekly mean relative humidities of the year were re- 
corded: 48-74%. Individual flight periods took place with night- 
time relative humidities ranging between 39 and 100%. Flight 
periods began at temperature-relative humidity combinations between 
29°C/39% RH and 24°C/iOO% RH. Nearly two inches of rain 
had fallen during the summer rainy season ( June-September) prior 
to the flight season, and four significant rains (0.3 to 1.5 inches) 
occurred during the season itself. No flights took place on three 
nights during the 43-day season, apparently because of rain or con- 
siderably cooler temperatures. All flights were staged during dark- 
