Genetic Variation in the Feeding Behavior of Isofemale Lines of Nesidiocoris tenuis.

Abstract

Simple SummaryBreeding of species for the benefit of humans is a well-known practice in plants and some vertebrates. However, its application to invertebrates, specifically biocontrol agents, is rather new and there is still a lack of information on breeding parameters of key traits. In this study, we address two important traits for biocontrol, i.e., the phytophagy and zoophagy of a population of the zoophytophagous predator Nesidiocoris tenuis. Here, we determine whether there is variation in these two traits and the proportion of that variation that has a genetic basis. Our results revealed the presence of genetic variation in both traits for this population. Genetic variation observed in zoophagy was larger than that found in phytophagy. These findings are relevant to the field of genetic improvement of biocontrol agents, since it reports quantitative values necessary for potential breeding programs. Moreover, our results suggest that if such variation is maintained in larger populations, it might be possible that selection for more zoophagous individuals could entail a reduction of the damages derived from its phytophagy. Furthermore, this study sheds light on genetic tools that could be applied to improve the biocontrol practice and, consequently, contribute to a more sustainable agriculture.Zoophytophagous predators provide biocontrol services in various major crops of modern horticulture due to the combination of its predatory capacity and the induction of plant defenses derived from its phytophagy. However, under certain conditions of prey scarcity, these natural enemies can inflict plant damage. Exploitation of genetic variation and subsequent selective breeding on foraging traits is a potential alternative to overcome this inconvenience. In this study, we quantified the genetic variation of phytophagy and zoophagy of Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae), a zoophytophagous predator widely used in tomato crops to suppress key pests. We compared nine isofemale lines on their capacity to produce necrotic rings and wilting on tomato plants as a proxy for phytophagy, as well as their efficacy to prey on Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) eggs, as a proxy for zoophagy. Differences between isofemale lines in phytophagy and zoophagy indicated a genetic basis. Variation found in the zoophagy levels was larger than that in phytophagy levels. Our results showed that there is a genetic basis for the variation observed in the feeding behavior of isofemale lines of N. tenuis, highlighting the potential importance of selective breeding for such traits of biocontrol interest.