Fig. 4

Effects of PEITC and methanol on biospeckle intensity (see Table 1 for definition of parameters). a–c Changes in the Total Biospeckle Intensity of bacterial feeder, plant feeder and Trichodorus samples 2 and 24 h after treatment, expressed as the percentage of Total Biospeckle Intensity measured before treatment. Error bars represent the standard error for N = 5 (N = 6 for Trichodorus in PEITC). d–f Biospeckle intensities for the different feeding groups detected above a threshold of 20. Measurements at 0 h are prior to the application of chemicals, while 2 and 24 h are post-treatment measurements. Biospeckle intensities are shown as the average of all detected objects and error bars represent the standard error. The asterisk denotes the only observation 24 h after the application of methanol which was not replicated