6 
Psyche 
[March 
the far smaller size of its colonies, the same "behavior is true of Ph . 
creightom. The matter becomes even more complex when it is neces- 
sary to deal with species which bring in insect remains during most 
of the year and gather seeds only at intervals. Such species are ex- 
ceptionally difficult to handle for, unless they make a conspicuous 
chaff pile, which they often fail to do, the only way toi prove that 
they have gathered seeds is to expose the seed chambers in the nest. 
This behavior is found in Ph. bicarinata, cerebrosior , sitarches f 
rugulosa and xeroplula. It is only by stretching a point that these 
five species can be considered as harvesters, since their main reliance 
is on insect food. This leads directly to the problem of the strictly 
carnivorous species of Pheidole. In the writer’s opinion there are 
considerably more of these than has been supposed. As early as 1908 
W. M. Wheeler had recognized that Ph. dentata and hyatti are 
carnivorous and predacious (3). In 1955 Creighton and Gregg 
showed that Ph. titanis is termitophagus (4). In 1964 the writer 
pointed out that Ph. (C.) clydei is an entomophagus scavenger (5). 
But there are other species which can be added to this list. It should 
certainly include Ph. grallipes and vallicola , both of which are in- 
sectivorous and predatory. It also appears that Ph. floridana and 
metallescens belong here. In 1958 Van Pelt showed that both species 
are attracted to a variety of baits (6). But when they are not baited 
or allowed access to kitchen scraps, each brings insect remains to the 
nest. They have not been reported as seed collectors and the writer 
has been unable to find stored seeds in the nests. 
The above discussion should show why it is misleading to char- 
acterize Pheidole as a genus of harvesters. There is obviously no 
possibility of applying such a designation to the growing number of 
carnivorous species, nor is the situation much better in the equally 
large number of species which utilize insect food at least as often as 
they do seeds. For the truth of the matter appears to be that species 
which subsist mainly on seeds are in the minority in the genus Phei- 
dole. One further detail is pertinent in this connection. It now 
seems probable that the major of Pheidole functions more often as 
a guard than it does as a seed crusher. The writer has been able 
to observe the guarding function in the majors of Ph. clydei , dentata , 
floridana, macclendoni, metallescens , militicida and ridicula. Only 
in ridicula has the major also functioned as a seed crusher. It is ob- 
vious that the major of a carnivorous species can have no occasion to 
crush seeds and the fact that the guarding function cuts across food 
preferences would seem to indicate that it, rather than seed crushing, 
is the basic response of the major of Pheidole. 
