Vs. Banschbach et Jm. Herbers, COMPLEX COLONY STRUCTURE IN SOCIAL INSECTS .1. ECOLOGICAL DETERMINANTS AND GENETIC CONSEQUENCES, Evolution, 50(1), 1996, pp. 285-297
For social insect species, intraspecific variation in colony social st
ructure provides an opportunity to relate the evolution of social beha
vior to ecological factors. The species Myrmica punctiventris is a cav
ity-dwelling forest ant that exhibits very different colony structures
in two populations in the northeastern United States. Combined data f
rom seasonal censuses, allozyme electrophoresis, and worker hostility
tests showed that a population of M. punctiventris in Vermont was stri
ctly monogynous and seasonally polydomous. The same procedures showed
that a population of M. punctiventris in New York was facultatively po
lygynous and predominantly monodomous. Genetic relatedness among colon
y-mates was not different from Hamilton's expected values in the Vermo
nt population and was consistent with little exchange of ants between
colonies and single-mating of queens. In contrast, relatedness was low
er in New York, and examination of nest-mate genotypes revealed exchan
ge of ants between colonies, high rates of colony loss and replacement
of queens, or multiple-mating of queens. The genetic structure of the
Vermont population was consistent with no inbreeding, but in New York
, the population genetic structure reflected microgeographic subdivisi
on and inbreeding. Previous study of the ant communities at these site
s implicates nest-site limitation in New York as a primary constraint
on social structure.