Temporal changes in activity-density of Cylisticus convexus (A) and Trachelipus rathkii (B) and soil physical characteristics in an urban forest in Baltimore. Mean numbers of individuals captured daily per trap (C. convexus: open circles, T. rathkii: asterix) ± SE are shown. Dotted line: mean daily soil temperature at 10 cm; dashed line: smoothed soil temperature; open triangles: volumetric soil moisture content.