1966] 
Nutting — Paraneotermes 
139 
for relative humidity and saturation deficit, is presented in figure 4. 
The combinations of temperature and relative humidity at the time 
of sunset plus 15 minutes are plotted in figure 6. Daily flights almost 
always begin while temperature is falling steadily and generally near 
or shortly after the low in humidity for the day. 
Moisture 
Rainfall and Soil Moisture. — The relation of the flight season 
and the daily flights to rainfall for 1962 and ’63 is shown in figures 1 
and 2. For these years, where the first and last flights were estab- 
lished with reasonable certainty, the flight season began well in ad- 
vance of the summer rains. In 1962 the first flight was staged 81 
days after the last measurable rain of 0.09" was recorded on March 
20. Eight flights had occurred before the next measurable rain 
(0.02") had fallen 99 days later. The next year, 51 days elapsed 
between the last measurable rain of 0.58" on April 25 and the first 
flight, with at least three flights occurring before the first measurable 
rain (0.01") in 69 days. In 1965 the first flight took place 17 days 
after 0.0 1" was measured on May 12. These records established 
beyond any doubt that Paraneotermes does not begin swarming in 
response to seasonal rainfall. This is apparently the case with many 
dry-wood termites, such as Cryptotermes (Weesner, ’60, p. 160). 
Although a few of the larger flights have taken place on days fol- 
lowing substantial rains, the general pattern seems to be one in which 
rain is actually avoided (figs. 1 and 2). Of 29 flights observed in 
the study area during 1962, only eight occurred on rainy days, and 
on each of these days only 0.05" or less was measured. Further, 
flights did not take place if any rain occurred within an hour before 
or after flight time. A similar pattern is evident for other years, 
although the data are much less complete. 
No measurements of soil moisture have been made in connection 
with the flights of this termite. It is certain, however, that the gen- 
eral floor of the desert is hard-packed and that the soil is extremely 
dry to a depth of many feet during the early part of the season. The 
matter of the selection of nesting site is briefly covered under Post- 
Flight Behavior. 
Relative Humidity. — Figures 1 and 2 show the relation of the 
total flight season to the weekly mean relative humidity for two 
years. The seasons took place within means of 50. 1 and 79.1% (’62) 
and 40.6 and 86.9% relative humidity (’63). These ranges include 
very nearly the extremes for each year, and cover the summer trend 
from very low to high mean humidities. 
