Factors affecting carabid (Coleoptera: Carabidae) assemblages in successional sub boreal spruce forests, with special reference to their interaction with ants (Hymenoptera: Formicidae).

Carabid (Coleoptera: Carabidae) assemblages in west central British Columbia are relatively poorly examined. Additionally, the influence of ants (Hymenoptera: Formicidae) on carabid assemblages is infrequently acknowledged as a factor that affects carabid diversity, distribution, and activity. The purpose of this study was to examine carabid assemblages in successional sub boreal spruce forests in west central British Columbia, and specifically how they are affected by two species of ants Formica aserva (Forel) and Camponotus herculeanus (L.). Data pertaining to carabid and ant activity-abundance were collected over a chronosequence of successional forest stages by pitfall trapping. The data were analyzed for the effects of canopy cover, vegetation, and ant influence on carabid species assemblages. Carabids were shown to be influenced by the presence of ants on the basis of a pattern of avoidance, and the frequency of carabid injuries were significantly related to F. aserva activity-abundance. An experiment where F. aserva nests were introduced into a clearcut was conducted to further examine this relationship confirmed that carabid activity-abundance is affected by ant presence. --P. ii.