Congruence of data from different trapping periods of ant pitfall catches (Hymenoptera: Formicidae)

Ants are prominent study organisms in basic and applied ecology. Pitfall traps are among the most widely used methods for arthropod density assessment. We appraised the congruence of data from two periods of pitfall trapping for the study of ant assemblages in dry grassland. Spearman rank correlations and non-metric multidimensional scaling ordination plots of the Bray-Curtis similarity index suggested that pitfalls deliver a repeatable picture of ant assemblages irrespective of habitat management and sampling plot shape, provided that a sufficient number of traps are used. Among density statistics, scaled abundance performed most convincingly.