Settlement and distribution of colony-founding queens of the arboreal ant, Crematogaster ashmeadi , in a longleaf pine forest

Abstract

Crematogaster ashmeadi is the dominant arboreal ant occurring on longleaf pines in the Apalachicola National Forest of northern Florida. Newly-mated C. ashmeadi queens preferentially founded colonies in abandoned beetle galleries in the dead branches of longleaf pine saplings. There was a positive association between the frequency of queens in trees, several size-related tree characteristics and the amount of insect boring activity in dead branches. The dispersion of newly-mated queens among trees was clumped, suggesting that these queens selected founding sites according to their suitability for colony founding, and that these favorable characteristics were clumped among saplings. The occurrence of founding nests was not related to the prior presence of other ants on the tree. Survival of incipient colonies during the first year was low (7.6 %), and their dispersion was not different from random. One possible explanation for this change in dispersion over the year is aggressive interference competition between incipient colonies, although random mortality cannot be discounted. Overall, the distribution of young C. ashmeadi colonies in longleaf pine saplings was probably determined by several factors including: the distribution of saplings, the distribution of suitable founding sites within these saplings, and aggressive interactions among incipient colonies, conspecifics and heterospecifics. C. ashmeadi probably gains dominance through a combination of early colonization and aggressive interference competition.