Abstract: Since 2006 the South American leaf miner Tuta absoluta occurs in tomato crops inEurope. In the winter season tomatoes from Mediterranean countries are being packed in packingstations in The Netherlands. Tuta absoluta is frequently monitored by means of pheromone trapsin the packing stations. In order to safeguard the current practise of biological control of pestsand pollination by bumble bees in tomato we investigated the effectiveness of pesticides and thepossible occurrence of indigenous natural enemies. A rearing of T. absoluta was set up in 2009 incages in a well confined greenhouse. Pesticides, which are currently applied against caterpillarsor leaf miners were tested on the leaf miner T. absoluta. Particularly diflubendiamide (Fame),abamectin (Vertimec), spinosad (Tracer) and emamectin benzoate (Proclaim) were effective againstcaterpillars of T. absoluta. In 2010 a field survey was carried out in order to find natural enemies ofT. absoluta in The Netherlands. Young leaf miners were parasitized at least by two ectoparasitoids,Elachertus inunctus and Pnigalio soemius (Hymenoptera: Eulophidae). Dicyphus errans andHeterotoma sp. (Heteroptera: Miridae) and an unidentified mason wasp (Hymenoptera: Euminidae)were observed to attacking T. aboluta larvae, with D. errans being the most common species.