Activity-stimulating phenomena caused by field-disturbance in the use of pitfall-traps

The influence of several mechanical field disturbances, when using pitfall-traps for activity determinations, is analysed. The disturbances result in higher catches of surface-dwelling Collembola; the animals being stimulated to higher locomotory activity.The disturbance by walking in the field results in a multiple of the control catch. This effect lasts for about 1 hour.The digging-in effect lasts for about two days but more or less different for the various species. The cause is sought in the CO₂ production in the soil, which is considerable after soil disturbances. The reaction of Collembola to rather high CO₂ concentrations in the air results in an increase of the locomotory activity.Another interpretation, namely attraction to CO₂ sources, could not be demonstrated.