Biological control of <i>Tuta absoluta</i> through releases of <i>Trichogramma cacoeciae</i> parasitoids and <i>Macrolophus pygmaeus</i> predators in northeastern Tunisian greenhouses

<i>Tuta absoluta</i> (Meyrick) (Lepidoptera: Gelechiidae) is the most destructive pest of tomato worldwide. Biological control has always been considered as a promising management approach of this pest in tomatoes. In this context, we evaluated the effectiveness of releasing <i>Trichogramma cacoeciae</i> Marchal parasitoids or <i>Macrolophus pygmaeus</i> (Rambur) predators in controlling <i>T. absoluta</i> in greenhouse tomatoes of northeastern Tunisia. Two weekly releases of either <i>M. pygmaeus</i> at 1 adult/m² or <i>T. cacoeciae</i> at 20 adults/plant were assessed. Our results indicated that parasitism rates were significantly higher on the apical tomato leaves compared to the middle leaves. We found that the number of <i>T. absoluta</i> eggs and larvae was significantly reduced after releasing <i>T. cacoeciae</i>, while releases of <i>M. pygmaeus</i> did not significantly reduce <i>T. absoluta</i> densities. The present study demonstrated the great potential of releasing <i>T. cacoeciae</i> in controlling <i>T. absoluta</i> in greenhouse tomatoes of northeastern Tunisia. However, further studies are needed to evaluate other release rates of <i>M. pygmaeus</i> that could show promising effectiveness against <i>T. absoluta</i> in northeastern Tunisian greenhouses.