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

Abstract

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 Nesidiocoristenuis (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.

Response of mirid predators to synthetic herbivore‐induced plant volatiles

“…On the one hand, attraction of predatory mirids and repellence of pests could result in predatory mirids lacking enough food to establish and develop in the crop. On the other hand, the risk of plant damage caused by predatory mirids would increase (Chinchilla‐Ramírez et al, 2020, 2021). Certain strategies could be used to limit this problem such as the application of sugars, either by using hydrocapsules filled with sugars or by directly spraying sugars in the field, which can reduce plant damage caused by N. tenuis (Urbaneja‐Bernat et al, 2019) and facilitate its establishment (Urbaneja‐Bernat et al, 2013, 2015).…”

Use of zoophytophagous mirid bugs in horticultural crops: Current challenges and future perspectives

“…42 In one of them, using isofemale lines of N. tenuis, genetic variation of the feeding behavior, both phytophagy and zoophagy, was quantified. 46 The ability of N. tenuis to produce necrotic rings and wilting on tomato plants differs across isofemale lines, as well as predation on E. kuehniella eggs. The lower heritability obtained for phytophagy when compared to zoophagy suggest that phytophagy could be more challenging to target in breeding programs due to the interaction of several factors, as mentioned above, whereas the variation found for zoophagy-related traits is promising for increasing N. tenuis efficacy as biocontrol agent.…”

“…The isofemale line approach consists of establishing several lines, each from a single mated female, and the quantification of the desired traits in several offspring produced by each female. This methodology is currently being applied to N. tenuis for the selection of strains with distinct degrees of phytophagy and zoophagy 42 . The complete genomic code of N. tenuis has recently been released 43 .…”

“…Access to strains with less phytophagous behavior would allow higher mirid bug populations without the risk of crop damage. Currently, there are several research projects in progress with the objective of determining the possibilities of improvement of this trait in N. tenuis 42 . In one of them, using isofemale lines of N. tenuis , genetic variation of the feeding behavior, both phytophagy and zoophagy, was quantified 46 .…”

“…Currently, there are several research projects in progress with the objective of determining the possibilities of improvement of this trait in N. tenuis 42 . In one of them, using isofemale lines of N. tenuis , genetic variation of the feeding behavior, both phytophagy and zoophagy, was quantified 46 . The ability of N. tenuis to produce necrotic rings and wilting on tomato plants differs across isofemale lines, as well as predation on E. kuehniella eggs.…”