1966] 
Nutting — Paraneotermes 
33 
figured from the hygrothermograph records with the aid of a plani- 
meter (Cutright, ’27). Evaporation data are available (U. S. De- 
partment of Commerce, ’62; ’63) from measurements made daily 
at 5 :00 PM on the campus of the University of Arizona, Tucson, 
2.5 mi. SSW of the study area. Saturation deficit was calculated for 
time of sunset plus 15 minutes at Tucson, and for certain other 
times, on the basis of hygrothermograph records. Rainfall was meas- 
ured daily with a simple plastic collecting gauge near the center of 
the area from midnight to midnight. Illumination at the zenith was 
measured several different times with a Weston photographic ex- 
posure meter (Master II, Mod. 735). During 1962 barometric 
pressure was continuously recorded on a temperature-compensated 
Taylor recording barometer. Some observations were made on flights 
from a laboratory colony in an 8 X 8-foot walk-in refrigerator which 
was equipped with a Partlow recording temperature program control 
(Mod. RCS) capable of providing any desired daily or weekly 
temperature pattern. All times are Mountain Standard and based 
on the 24-hour clock. 
Development of alates and pre-flight behavior. — Light 
(’37) termed the large aggregations of nymphs and soldiers of this 
species “temporary outposts” or “foraging subcolonies” ; no repro- 
ductives of any form, eggs or small nymphs have yet been found in 
them. Samples from 19 subcolonies collected in or within 25 miles 
of Tucson have revealed subimaginal nymphs (with large wing pads) 
to be present between August 30 (1962) and May 2O 1 (1961). On 
the latter date an entire subcolony was removed from a large timber 
beneath the steps of a farm building and set up in a laboratory ob- 
servation nest. It contained 39 soldiers and 760 nymphs, many of 
them pre-alates. Between June 2 and 15, all of these had developed 
into 130 alates at laboratory temperatures only slightly less variable 
than, and averaging a few degrees below, those outside. By a most 
fortunate coincidence another subcolony was found on June 14, 1961, 
in the roots of a dead palo verde tree ( Gercidium microphyllum ) . It 
contained 104 soldiers, at least 1100 nymphs (no pre-alates) and 190 
alates. No flights were observed in the Tucson area in 1961 until 
July 5, although it is likely that this was not the first flight of the 
season. The above evidence shows an abrupt and rapid mass develop- 
ment of alates within three weeks, probably less, of the first flight. 
Although no local soil temperature records are available it seems 
reasonable to assume that this maturation is a direct result of the 
intensei heating of the soil which occurs during the very clear, dry 
months of May and June. Monthly mean air temperatures increase 
