Suitability of European Trichogramma Species as Biocontrol Agents against the Tomato Leaf Miner Tuta absoluta

The tomato leaf minerTuta absoluta, originally from South America, is an invasive species threatening European tomato crops. Since various insecticides have become ineffective in controllingT. absoluta, effective and environmentally friendly alternatives are needed. Biological control, especially byTrichogrammaparasitoids, is considered to be an effective means of reducing this pest. Thus, the aim of our study was to identify promising candidates ofTrichogrammaparasitoids for biological control ofT. absolutain Europe. We assessed the efficiency of nine EuropeanTrichogrammaspecies and compared them toTrichogramma achaeae, as this species is already commercially available. Firstly, we verified species identity of the 10 rearing strains using molecular and morphological methods. Then, host acceptance, host preference (T. absolutavs. rearing hostSitotroga cerealellaeggs) and host searching capacity were tested under laboratory conditions. Our results indicated thatT. nerudai,T. pintoiandT. cacoeciaeachieved a similar level of parasitism on potted tomato plants asT. achaeae. For the next step, these promising strains should be tested under greenhouse conditions.