Reducing the plant damage caused by the zoophytophagous predator Nesidiocoris tenuis through genetic selection

Abstract: The zoophytophagous predator Nesidiocoris tenuis has proven to be a highly
effective natural enemy in protected tomato key pests. In the Mediterranean basin, this
predatory mirid bug has been extensively used for the biological control of the whitefly Bemisia tabaci and the South American tomato pinworm Tuta absoluta. However, due to its
phytophagous behavior, N. tenuis can seriously damage tomato plants when the level of prey is scarce. Previous results using an isofemale line approach demonstrated a genetic basis for
phytophagy and zoophagy of this mirid bug. One of these isolines was selected for its relatively lower phytophagy compared to a commercial strain. In this study, we evaluated several lifehistory traits of the IVIA strain of N. tenuis, which has been selected for more than 50 generations, and compared them to those of a commercial strain in laboratory and greenhouse conditions. Our results showed that the IVIA strain exhibited higher reproductive values, greater voracity, and less damage to tomato plants, as compared to the commercial strain. A step further, the IVIA-strain controlled B. tabaci and T. absoluta in greenhouse experiments at the same level as the commercial strain but produced less damage to the plant. Interestingly, the use of microsatellite markers revealed genetic differentiation between the IVIA strain and the commercial strain. Our results highlight the potential of selective breeding for improving biocontrol traits of interest in N. tenuis and open the door to differentiating selected strains of N. tenuis using molecular techniques.