DISTRIBUTION AND BIOLOGY OF THE PRIMITIVE 
DRY-WOOD TERMITE 
PTEROTERMES OCCIDENT IS (WALKER) 
( KALOTERMITIDAE ) 1 
By W. L. Nutting 
Department of Entomology, University of Arizona, Tucson 
This summary of recent studies on Pterotennes is part of an irreg- 
ular series of contributions to the biology and ecology of the relatively 
rich termite fauna of southwestern North America. The fact that 
such a large and primitive termite has been known from about a 
dozen rather poorly documented collections is indicative of the need 
for such knowledge in this rapidly developing region. Indeed, very 
little additional information on this species has beeen published since 
the important summary by Banks and Snyder in 1920. Most of the 
25 new records have been accumulated by members, students and 
friends of the Department of Entomology at the University of 
Arizona, largely within the last ten years. The most extensive addi- 
tions were made during a trip through Baja California in the late 
summer of 1959 by Floyd G. Werner and Keith W. Radford. Their 
almost nightly collections of this termite in a light trap indicate that 
their schedule must have coincided closely with the peak of the 
flight season. Although most of the records consist of alates taken 
in light traps, in seven instances one or more colonies have been 
found which have added much new biological information. 
Distribution. This species has long been included in the large, 
cosmopolitan genus, Kalotermes. On the basis of careful morpho- 
logical and taxonomic considerations, Krishna (1961) removed it 
to a previous place in the genus Pterotermes. Because of its probable 
key position in arising directly from ancestral kalotermitids and its 
apparent rarity, all readily available records have been brought to- 
gether in Table 1 and plotted in Figure 1. Those in Mexico, 
particularly from the generally unfamiliar geography of Baja Cali- 
fornia, have been numbered to facilitate their location. 
The distribution is thus found to conform closely to the Sonoran 
Desert as it has been delimited on the basis of the vegetation. A few 
marginal localities in southeastern Arizona and southern Baja Cali- 
fornia might be considered as local extensions of the region. A brief 
characterization of this, the richest of the four areas comprising the 
Arizona Agricultural Experiment Station Journal Article No. 1149. 
Manuscript received by the editor June 22, 1966 
