1982] Alloway, Buschinger, Talbot, Stuart & Thomas 
271 
and we presume that others are remnants of declining colonies. 
However, we can neither distinguish the two kinds of nests nor 
determine their relative frequencies. Reference to the proportion of 
nests producing all-male broods is not helpful because, in some 
species of Leptothoracine ants, female larvae can hibernate twice 
before pupating (Buschinger et al. 1975). Thus, a queenless colony 
might continue to produce female pupae for one or two years. 
Further work is needed to devise a simple means of distinguishing 
declining colonies from the queenless nests of polydomous colonies. 
Second, we would like to know how frequently these species 
employ the various modes of colony foundation which we have 
observed and postulated. Altogether, we report observations of 872 
nonincipient nests of L. ambiguus, 342 nonincipient nests of L. 
longispinosus, and of 8 and 7 apparently incipient nests of these two 
species. If one assumed that the frequency of apparently incipient 
nests represented the frequency of incipient colonies in the popula- 
tion, one would have to conclude that the average lifespan of a 
colony is unreasonably long. Thus, we were led to propose budding 
as a frequent means of colony foundation. This proposal needs 
verification. 
However, it was the degree to which L. ambiguus, L. curvispino- 
sus, and L. longispinosus are subject to social parasitism which 
initially aroused our interest; and several of the behavioral processes 
which we have described suggest means by which social parasitism 
might either evolve or be maintained. Colonies of all three species 
sometimes adopt newly mated conspecific queens, and colonies of 
L. ambiguus and L. longispinosus are sometimes founded pleo- 
metrotically. Since both these forms of polygyny require the peace- 
ful coexistence of queens and of workers which are the offspring of 
different queens, both forms of polygyny are factors which might 
render these species susceptible to social parasitism. To be accepted 
by a host-species colony, a parasite queen must somehow convince 
the host workers and perhaps the host queen or queens that she is a 
legitimate potential colony member. Since the queens and workers 
of these species naturally accept supernumerary queens, the parasite 
female’s task is probably simplified. 
Moreover, the tendency to seek adoption by existing colonies and 
the tendency to join pleometrotic foundress associations may repre- 
sent preadaptive traits from which parasitic modes of colony founda- 
