Differences in locomotory activity between male and female Carabus hortensis (Coleoptera: Carabidae) in a pine forest and a beech forest in relation to feeding state

The locomotory activity of both hungry and satiated individuals of Carabus hortensis L. was studied both in pine and beech forest by tracking the beetles by using a portable harmonic radar system. The degree of locomotory activity as well as walking distances was recorded for both males and females. Hungry males and females show a similar degree of activity. When satiated, locomotory activity of females is significantly lower than that of males in both types of forest. These differences in locomotory activity are considered in the context of male-to-female ratios in pitfall catches. It is proposed to use the male-to-female ratio for C. hortensis, and possibly other species, as an indicator of food accessibility in forest habitat: the more males in pitfall catches in relation to females, the better the food situation in the forest.