Habitat structure, dispersal strategies and queen number in two boreal Leptothorax ants

Abstract

Abstract. In two nearctic ants, Leptothorax canadensis and Leptothorax sp. A, young queens may either found their own nest solitarily after mating or seek adoption into an established colony. Whether a queen disperses or not is associated with genetically determined queen morphology in Leptothorax sp. A. Whereas a majority of winged queens attempt solitary colony founding after mating, most wingless, intermorphic queens return to their maternal nests and new colonies are founded by budding after hibernation. The latter strategy appears to be correlated with patchy, isolated habitats, whereas in extended boreal forests dispersal on the wing is probably more common. Alternative dispersal strategies strongly affect the average number of queens per colony and seasonal fluctuations of colony structure.

The ant (Hymenoptera: Formicidae) communities of the central interior of British Columbia: Adaptations to a temperature-constrained environment.

“…The boreal Leptothorax spp. are considered to be usually polygynous (i.e., multiple queens), with both nest founding by single and multiple queens as well as the later acceptance of additional queens (secondary polygyny) into established nests (Heinze 1993b). Secondary queen acceptance, however, may not always be successful, as illustrated ( Figure III.4…”

“…Both species, especially L. muscorum (Heinze 1993b), are physically small, do not form large colonies, and forage within approximately 2 m of their nest sites (Brian et al 1965) (see Appendix 1.3). Thus, there is extensive space available in harvested sites for nest establishment and foraging.…”

“…(Elmes and Keller 1993), and Leptothorax spp. ants (Heinze 1993b. Species displaying this characteristic often, but not exclusively, reproduce through colony budding.…”

“…An as yet undescribed species of Leptothorax in eastern Canada {Leptothorax sp. A), in which many virgin queens were wingless, making colony foundation through budding obligatory, has been described (Heinze 1993b). …”

“…Although polygynous and polydomous colony expansions may be a common mode of colony spread in boreal forests, queen flights into new habitat is also common (Cherix et al 1991;Heinze 1993b;Punttila 1996) and the regression models may provide some information about habitat selection. Habitat selection during such flights has been little studied because of the difficulties in exactly anticipating the timing of mating flights and following queens as they disperse.…”