1974] 
Nutting , Blum, & Fales — Tenuirostritermes 
175 
The high proportion of soldiers maintained by T. tenuirostris, and 
presumably many other free-foraging termites, certainly attests to 
their great importance in the colony. Our figure of 20% soldiers in 
combined collections from four different colonies is in fair agreement 
with Light and Weesner (1955) who determined that incipient 
colonies of this species usually contained between 25 and 33% 
soldiers. Three of our foraging groups combined contained 44.9% 
soldiers, while a single group contained 71.3%. Ernst (1959) re- 
ported 70 to 90% soldiers in outer portions of his laboratory colony 
of N asutitermes sp. from the Ivory Coast. Although demands on 
the defensive capabilities of the soldiers underground must be trivial 
or rare, indeed, these figures show that a very high proportion of 
soldiers is mobilized for foraging parties. 
This situation is in striking contrast to that in another subterranean 
termitid, Gnathamitermes perplexus (Banks) ( Amitermitinae) , 
which is very common over the range of T. tenuirostris in southern 
Arizona. This species forages widely on the surface under cover of 
thin, soil sheeting which it builds over all types of dead plant ma- 
terial (Collins et al., 1973). Based on 74 foraging groups, the 
average soldier rworker ratio is 1:89 (1.11% soldiers). Individual 
groups ranged from 1 to 1031 termites and contained from 0.0 to 
9.10% soldiers (Nutting and Haverty, unpublished). 
During the few hours of field observations on the above-ground 
activities of T. tenuirostris , no encounters with ants or other small 
predators were seen. However, the presence of an impressive ant 
fauna in our study area lends further credibility to the importance 
of the soldier caste in the economy of this termite. In a preliminary 
study of the ants on the Santa Rita Experimental Range, Gaspar and 
Werner (unpublished) list 33 species, with high populations of 
Crematogaster coarctata vermiculata Emery and Forelius foetidus 
(Buckley), and estimate 1753 nests/ha for all species. About one 
fourth of the species are regular predators, while at least an addi- 
tional third are occasional predators or at least feed on animal matter. 
Many of them forage at night during the summer rainy season when 
T enuirostritermes is also most active on the surface. Although we 
have no estimates of colony size or density for the termite, its colonies 
are fairly common in the area and must contain several thousand 
individuals. 
