The BALTO project has succeeded in better understanding the tomato russet mite (TRM). Using a monitoring method with microscopic photos, a valuable scoring system was established. With these tools a damage threshold was established. The outcome is to intervene as early as possible, once you see damage to the stem of the tomato plants, you already have a loss of production.The trials also indicated that TRM does not survive a crop rotation. Lab tests determined which crop protection products are effective against TRM and these tests were repeated in field conditions. Not all lab results could be confirmed in field trials, but Vertimec and sulfur-based products also proved successful against TRM at greenhouse level. The other results were not as expected and left us wondering whether spraying technique could be of importance. Therefore, various spraying techniques were tested and especially the use of an optimal water volume appeared to play a major role in the effectiveness of crop protection products. An important success story is the search for a biological control agent. Several lab results suggested Pronematus ubiquitus as a potentially successful beneficial. The lab results were confirmed in small scale cage experiments and also in greenhouse experiments with a preventive presence of P. ubiquitus, the predatory mite A. lycopersici could be kept under control. In addition, side effects of various crop protection products on P. ubiquitus were tested. On a lab scale, Admiral, Closer, Neemazal and Xentari appeared to have little or no effect on the population development of the predatory mite. A greenhouse test confirmed this result for Closer, the other agents were not tested. However, there are still some questions about this biological control agent. On several occasions, the predatory mite found it difficult to establish itself in the crop and several releases were required per trial. In the trials it was established that initially there was no mildew on the plants where P. ubiquitus had established itself. This effect would be interesting to unravel and possibly extrapolate to other crops. And finally, the race dependence of this effect might be more important than previously thought.