Suitability of European <i>Trichogramma </i>Species as Biocontrol Agents against the Tomato Leaf Miner <i>Tuta absoluta</i>

• Main Authors: Lea Schäfer, Annette Herz
• Format: Article
• Language: English
• Published: MDPI AG 2020-06-01
• Series: Insects
• Subjects: biological control; host acceptance; host preference; invasive pests; species identification; tomato crops
• Online Access: https://www.mdpi.com/2075-4450/11/6/357

The tomato leaf miner <i>Tuta absoluta</i>, originally from South America, is an invasive species threatening European tomato crops. Since various insecticides have become ineffective in controlling <i>T. absoluta</i>, effective and environmentally friendly alternatives are needed. Biological control, especially by <i>Trichogramma</i> parasitoids, is considered to be an effective means of reducing this pest. Thus, the aim of our study was to identify promising candidates of <i>Trichogramma</i> parasitoids for biological control of <i>T. absoluta</i> in Europe. We assessed the efficiency of nine European <i>Trichogramma</i> species and compared them to <i>Trichogramma achaeae</i>, 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 (<i>T. absoluta</i> vs. rearing host <i>Sitotroga cerealella </i>eggs) and host searching capacity were tested under laboratory conditions. Our results indicated that <i>T. nerudai</i>, <i>T. pintoi</i> and <i>T. cacoeciae</i> achieved a similar level of parasitism on potted tomato plants as <i>T. achaeae</i>. For the next step, these promising strains should be tested under greenhouse conditions.