1971] 
Haskins Zahl — Dinoponera 
3 
to be sure, are still morphologically distinguishable from the workers. 
In Leptogenys, sens, str ., however, in some species of Rhytidoponera , 
and in Diacamma , Streblognathus, and Dinoponera , no caste mor- 
phologically distinguishable from the worker has ever been reported, 
though normal males, in some cases evidently well adapted to secure 
outbreeding within the species, are the rule. A number of years 
ago Wheeler and Chapman (1922) described a male of a Philippine 
species of Diacamma in copula with an individual morphologically 
indistinguishable from a typical worker, suggesting the lack even 
of an identifiable ergatogyne in this species, the “workers” differing 
only in the presence or absence of a functional spermatheca and 
perhaps in the degree of ovariole development — a situation well 
known in several species of Rhytidoponera (Haskins and Whelden, 
1965). It became of interest, therefore, to learn whether such 
workerlike individuals form the normal reproductive caste in Dino- 
ponera. That this situation, if real, could typify a rather ancient 
evolutionary condition is hinted by earlier findings of F. M. Car- 
penter. Carpenter suggested some years ago (1930) that a fairly 
close fossil relative of both Dinoponera and Streblognathus may 
be Archiponera wheeleri, described by him in 1930 from the Mio- 
cene Florissant shales of Colorado. The absence of described mor- 
phologically differentiable females in either Dinoponera or Stre- 
blognathus (1929; 1930) gave special emphasis to a search for such 
a caste among the fossils of Archiponera. No examples were dis- 
covered, though typical winged males were described. 
The observations to be presented confirm the production of workers 
by one or more wild-collected females of Dinoponera grandis, indis- 
tinguishable from workers in external morphology, in the artificial 
nest. 
M aterial 
The monotypic ponerine genus Dinoponera has been known since 
1830, when its single species, D. grandis was described by Guerin 
from Para and Bahia, Brazil (1830). Carpenter noted (1930) 
that apparent morphological affinities of both it and the South 
African monotypic form Streblognathus aethiopicus to fossils of the 
Miocene Archiponera wheeleri in the Florissant shales could sug- 
gest that the two modern species are ancient relicts of an archaic 
ponerine complex which originally had a much wider distribution. 
The range of D. grandis given by Carlos Emery (1911) is 
“Middle American tropics as far as Paraguay,” and collecting 
localities for various described subspecies recorded up to that time 
