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Psyche 
[June 
meter on a number of evenings during each flight season. Para- 
neotermes has never been observed in flight until the light intensity 
has thus registered approximately 0.5 lumen per square foot (foot 
candles) or less. As with Neotermes tectonae Damm. (Kalshoven, 
’30) and probably other evening fliers, a few observations have shown 
that flight time is earlier on cloudy evenings. Considering the handi- 
cap of unknown nesting sites, the correlation between the beginning 
of the flight period and the time of sunset, or light intensity, is close. 
Whatever other advantages there may be, it is certain that many 
predators must be avoided by swarming at dusk. 
These few notes indicate the desirability of continuous and more 
sensitive measurements of light intensity in the vicinity of the emer- 
gence holes, whenever they can be found. The subject of rhythms 
and other aspects of behavior in the alates, nymphs and soldiers should 
also be studied in laboratory colonies under controlled illumination. 
Indeed, a most encouraging find has been made in this connection 
with certain species of ants. McCluskey (’65) has shown that en- 
dogenous activity rhythms of the males correspond to the timing of 
mating flight in the held. 
Flight behavior. — Considering the relative scarcity of evidence 
for Paraneoterm.es in the vicinity of Tucson and the numbers of 
alates appearing at lights, it is probable that there were no more than 
one or two colonies in or near the study area. On any basis, the 
number of alates involved in each daily flight would be very small. 
Assuming that most of the alates in 71 flights were from a single 
colony and visited the lights (front and back of house), the average 
Figure 5. Relationship between flight season of Faraneotermes simplici- 
cornis and evaporation rate and saturation deficit in Tucson, Arizona, 1962. 
Saturation Deficit, mm Hg at sunset + 15 min. (weekly mean) 
