A NEW PHEIDOLE WITH REVERSED PHRAGMOSIS 
(HYMENOPTERA: FORMICIDAE)* 
By William L. Brown, Jr. 
Department of Entomology, Cornell University 
INTRODUCTION 
A number of ants have plug-shaped heads, known or assumed to 
be used to stopper the nest entrance. This phenomenon, called phrag- 
mosis, is best understood in certain groups of Camponotus and Ceph- 
alotini (e.g. Wheeler 1910: 209-212, Szabo-Patay 1928, Creighton 
and Gregg 1954), but Wheeler (1901: 534; 1927) also described 
species with phragmotic-like heads in Pheidole , Crematogaster and 
the dacetine genus Colobostruma, while Patrizi (1948) published the 
problematical Solenopsis (Crateropsis) elmenteitae (placed by Etter- 
shank, 1966, in Oligomyrmex) . In most of these forms, either the 
queens or the soldiers, or both, are the phragmotic castes; in Colobos- 
truma leae , the assumed phragmotics are the queen and the monomor- 
phic workers. 
In the new species of Pheidole described below, phragmotic be- 
havior at some stage of the life cycle is indicated only for the queen 
caste, and even then is inferred from her aberrant body form. But 
in this case, the plug is formed, not by the head, but by the highly 
modified gaster (Figs. 6 and 7). 
Two queens showing this plug-like modification of the gaster were 
taken separately from rotten wood in rain forest in the general 
vicinity of Manaus during my collecting trip of 1962 in the Brazilian 
Amazon. In one case, and possibly in both, the queens belonged to 
definite colonies with workers, soldiers and brood. (Notes on collec- 
tion M-60 are ambiguous because two Pheidole queens, one of em- 
bolopyx and one of a totally different species, were in the vial with 
this number, but the notes state that “the” queen was taken apart 
from the soldiers, workers and brood. Probably one of the two 
queens was taken up in the aspirator along with bits of rotten wood 
without my knowing it.) 
The queen’s thickened scape base (with a gelatinous sheath) and 
the largely smooth and shining alitrunk with overhanging scutal 
margins, are “protective” characters suggesting social parasitism as 
a way of nest-founding for this caste. The strong similarities in color, 
sculpture and pilosity between the queens and the accompanying 
* Manuscript received by the editor November 27 , 1967 
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