Plant-mediated interactions between Tetranychus evansi and T. urticae spider mites - suppression test drought.

We infested three leaflets of 28-days old tomato plants (<i>Solanum lycopersicum</i> var Castlemart) with spider mites in four treatments, divided over two factors: (1) Mite species (<i>Tetranychus evansi</i> Viçosa-1 or <i>Tetranychus urticae</i> Santpoort-2) and (2) water regime (wet, dry). For the water regime, we either did not water the plants after their 21^st day (dry treatment), or we watered them twice a week by filling their trays maximally (wet). We infested the basal halves of three leaflets per plant, each from a different leaf, with 15 two to four days old adult females. We also placed 5 two to four days old adult <i>Tetranychus urticae</i> Santpoort-2 females on the upper halves of the same leaflets, while separating the leaflet halves through a lanolin barrier. We counted the number of eggs laid by the female mites on the upper halves of the leaf discs after four days. We also recorded which leaves were infested, how many treatment mites survived during four days (measured each day), and how many oviposition mites survived after four days. The experiment was carried out in two blocks in time, and both blocks were performed in a climate room (25°C, 16 : 8 h light : dark, 60% RH).