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

ABSTRACTTuta absoluta (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 Trichogramma cacoeciae Marchal parasitoids or Macrolophus pygmaeus (Rambur) predators in controlling T. absoluta in greenhouse tomatoes of northeastern Tunisia. Two weekly releases of either M. pygmaeus at 1 adult/m2 or T. cacoeciae 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 T. absoluta eggs and larvae was significantly reduced after releasing T. cacoeciae, while releases of M. pygmaeus did not significantly reduce T. absoluta densities. The present study demonstrated the great potential of releasing T. cacoeciae in controlling T. absoluta in greenhouse tomatoes of northeastern Tunisia. However, further studies are needed to evaluate other release rates of M. pygmaeus that could show promising effectiveness against T. absoluta in northeastern Tunisian greenhouses.KEYWORDS: Biocontrol agentegg parasitoidfield release ratelife stage densitymirid predatorSouth American tomato pinworm AcknowledgementsWe gratefully acknowledge the National Agronomic Institute of Tunisia (INAT) for the financial support during this study. The authors also thank the farmers in all study sites for their valuable contribution to this work.Availability of data and materialsThe data that support the findings of this study are available from the corresponding author, upon reasonable request.Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis work was funded by the European Union within the framework of the ENI Cross-Border Cooperation Programme Italy-Tunisia 2014–2020 - the INTEMAR project-IS_2.1_073 Innovations in the integrated control of insect pests and pathogens recently introduced on vegetable crops, grant number E64I18002460007.