Colour efficiency of sticky traps (means of summed catches) during the immigration period (IM). Comparison of C. melanoneura (A) and C. pruni (B) numbers on yellow and white traps. Comparison of C. melanoneura and C. pruni catches on white sticky traps during IM (C). Horizontal bars represent the medians, vertical bars represent the standard error of means. Statistical means are represented by triangles and interquartile ranges are indicated by boxes and outliers (if present) by black dots.