Figure 1

Photos of two species of spider mites, (a) Tetranychus urticae and (b) Tetranychus evansi, that we used in the experiments. Both species are pest of tomato plants but there is a difference in the colour of the soma (thorax, plus abdomen): green or whitish for T. urticae and red for T. evansi. These colours stem from pigment in the haemolymph and internal tissues (not the cuticle or the internal gut lumen).