“QUEENLESSNESS,” WORKER SIBSHIP, AND COLONY 
VERSUS POPULATION STRUCTURE 
IN THE FORMICID GENUS RHY T'lD OPONERA 
By Caryl P. Haskins 1 and Roy M. Whelden 2 
INTRODUCTION 
William Morton Wheeler, in his Colony Founding Among Ants 
(!933)> called special attention to the fact that in a number of 
formicid genera, and particularly in the socially primitive subfamilies 
Ponerinae and Cerapachyinae, typical alate female forms have never 
been described. In such genera as Onychomyrmex, Eusphinctus, 
Acanthostichus, Megaponera , and Plectroctena, this normal female 
may be replaced by a wingless ergatogyne, intermediate in structure 
between queen and worker. The same condition obtains among 
certain species of the archaic subfamily Myrmeciinae, as Wheeler also 
pointed out. In some cerapachyine species, normal females typically 
coexist with ergatogynes, and such caste duality occurs elsewhere also. 
In certain respects, the shift from a “queen-like” toward a “worker- 
like” form of reproductive female is curious and striking. At first 
sight it may even suggest a reversal of the trend tending to emphasize 
the dichotomy between more “vegetative” and more actively “for- 
aging” forms which, as Wigglesworth (1954) and Kennedy (1961) 
have pointed out, is so characteristic of evolution in insects generally, 
whether at the level of “successive polymorphism” in the juvenile and 
adult phases of the individual, or of “alternative polymorphism” 
among adult populations of such forms as aphids, migratory locusts, 
and the social insects. Among the ant genera cited, however, evolution 
from alate to ergatoid reproductive may only superficially appear to 
lie in that direction, for the ergatoid is clearly at least as effective a 
reproductive as the winged female. In most species with such females, 
moreover, it seems likely that the ergatoid has been directly derived 
by a stabilization of a queen-worker intercaste, as Brown (i960) has 
suggested, and merely replaces the normal queen, with no drastic 
change in the general economy or structure of the colony. Even in the 
ponerine genus Leptogenys sens, str., where the laying female is no 
longer morphologically distinguishable from the worker, the course 
of evolution still seems relatively clear. As Wheeler (1933) pointed 
out, a normal female is present in the related Lobopelta langii , and 
’Carnegie Institution, Washington, D.C. 
2 Haskins Laboratories, New Durham, New Hampshire 
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