Negative Effects of Phthorimaea absoluta-Resistant Tomato Genotypes on the Zoophytophagous Biocontrol Agent, Orius laevigatus (Fieber) (Hemiptera: Anthocoridae)

SIMPLE SUMMARY: We tested complex tri-trophic level interactions among a crop plant, a pest, and its natural enemy to maximize plant protection by compatible, combined contributions of crop resistance and biological control. Fitness components of the predatory bug Orius laevigatus were inferior to Phthorimaea absoluta-resistant tomato genotypes. These findings support the idea that biological control and crop resistance are incompatible in this system and highlight the need to consider biological control agents when developing crops for pest resistance. In sustainable integrated pest management systems, only the complementary actions of pest-resistant crops and biological controls could offer reliable and cost-effective plant protection. ABSTRACT: Complex interactions between host plant resistance (HPR) and biological control agents, particularly omnivorous predators, can shape the outcome of an integrated pest management (IPM) program. However, such interactions are seldom explored during plant breeding programs. Therefore, in the present study, we compared the performance of the omnivorous biological control agent Orius laevigatus on six tomato genotypes with different levels of resistance to the tomato leaf miner Phthorimaea absoluta. We found that the O. laevigatus fitness components (i.e., egg deposition, egg hatching rate, and duration of egg, early nymphal, late nymphal stages, and their survival) were inferior on the wild resistant genotypes (LA 716 and LA 1777) in comparison to the resistant domesticated genotype EC 620343 and the susceptible genotypes (EC 705464 and EC 519819). It appears that the adverse effects of tomato genotypes on O. laevigatus are determined mainly by glandular and non-glandular trichome densities on the leaves. Comparison of O. laevigatus response to the tested tomato cultivars to that of P. absoluta revealed significant positive correlations in duration of the egg stages, development time of early and late larval stages, and overall immature mortality in both species. It appears, therefore, that defensive plant traits operate in a similar way on the pest and its predator in the system. Overall, the present study of the tomato-P. absoluta-O. laevigatus system provides experimental evidence for the need to optimize pest management by employing intermediate levels of crop resistance together with biological control agents.