Combined effects of overwintering temperature and habitat degradation on the survival of boreal wood ant

The survival of insects during diapause may be affected by overwintering temperature and other environmental stress, such as anthropogenic habitat degradation. We experimentally studied the effects of overwintering temperature (+1 and +7A degrees C) and commercial forest clear-cutting on the overwintering survival of the forest-dwelling wood ant Formica aquilonia. We found that both the higher overwintering temperature and clear-cutting lowered the overwintering survival and body fat resources of Formica aquilonia. The survival and body fat resources were highest in lower temperature treatment forest nests and lowest in higher temperature treatment clear-cut nests. The overall survival of ants increased with higher body fat resources. It is possible that both forest clear-cutting and higher winter temperature due to possible climate warming may increase the wintertime mortality of wood ants and other forest-dwelling ants.