Orius laevigatus Induces Plant Defenses in Sweet Pepper

Pest management in protected sweet pepper crops primarily relies on biological control strategies. The release of the phytoseiid Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) and the anthocorid Orius laevigatus Fieber (Hemiptera: Anthocoridae) provides effective control of the two key pests of this crop, the thrips Frankliniella occidentalis Pergande (Thysanoptera: Thripidae) and the whitefly Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) (Sanchez et al., 2000; Calvo et al., 2009; van der Blom et al., 2009). A part of their direct effect on pest predation, zoophytophagous predators may induce defensive plant responses due to their plant feeding behaviour which involves the release of diverse volatiles through different pathways that are triggered by phytohormones (De Puysseleyr et al., 2011; Naselli et al., 2016; Pappas et al., 2015, 2016; Pérez-Hedo et al., 2015a,b). These responses may result in the repellence or attraction of pests and natural enemies. It is hence hypothesized that O. laevigatus would be able to induce plant responses in sweet pepper as has been demonstrated in other plantzoophytophage systems. As a first step to better understand the interaction between O. laevigatus and sweet pepper, the behavior of O. laevigatus on the plants was studied and plant feeding behaviour quantified to compare general behaviors. Orius laevigatus spends the majority of its time (38%) feeding on apical meristems and apical fresh leaves, which were also preferred residence locations (Bouagga et al., 2017)

Enhancing pest management in sweet pepper by the exploitation of zoophytophagy

During the last decades pest management in sweet pepper has shown noticeable development through the replacement of chemical control by biological control. The augmentative release of the predatory bug Orius laevigatus and the phytoseiid predatory mite Amblyseius swirskii satisfactory manage major pests invading sweet pepper, thrips and whiteflies. In order to enhance even more this biological control program and surmounted aphids problem, recent success was attributed to zoophytophagous mirid predators. The use of mirid predators is rare in sweet pepper greenhouses, however thesis results showed that mirid can enhance pest management in sweet pepper by the exploitation of zoophytophagy. The ability of mirids and O. laevigatus to predate open sweet pepper key pest and to induce plant defence was the most important found result in this thesis. A possible augmentative release of predatory mirids with A. swirskii is the new strategy that we propose to sustain sweet pepper pest management.Durante las últimas décadas, el control de plagas en el pimiento ha mostrado un desarrollo notable a través el reemplazo del control químico por control biológico. La liberación aumentativa del chinche depredadora Orius laevigatus y el ácaro depredador Amblyseius swirskii manejan satisfactoriamente las principales plagas, trips y mosca blanca. Con el fin de mejorar aún más este programa y superar el problema de los áfidos, se atribuyó el éxito reciente a los depredadores miridos zoofitofagos. El uso de miridos es raro en los invernaderos de pimiento, sin embargo, los resultados de la tesis mostraron que mediante la explotación de la zoofitáfia se puede mejorar el manejo de trips, mosca blanca y áfidos. La capacidad de los miridos y de O. laevigatus de preceder a la plaga clave del pimiento e inducir la defensa de la planta fue el resultado más importante encontrado en esta tesis. Una posible liberación aumentativa de los mirídos con A. swirskii es la nueva estrategia que proponemos para mantener el control de plagas del pimiento.Programa de Doctorat en Cièncie

Tomato plant responses to feeding behavior of three zoophytophagous predators (Hemiptera: Miridae)

Plant responses induced by zoophytophagous plant bugs (Miridae) have not been thoroughly studied. Here, we show that three different zoophytophagous predators (Nesidiocoris tenuis, Macrolophus pygmaeus and Dicyphus maroccanus) have different capacities for the induction of responses in tomato plants, resulting in varying degrees of attractiveness of the plants to pests and natural enemies. Tomato plants punctured by N. tenuis were less attractive to the whitefly Bemisia tabaci and to the lepidopteran Tuta absoluta. In contrast, tomato plants punctured by M. pygmaeus and D. maroccanus were not able to repel B. tabaci and, more interestingly, became more attractive to T. absoluta. The ability of N. tenuis to make tomato plants less attractive to B. tabaci was attributed to the activation of the abscisic acid (ABA) signaling pathway, which was only up-regulated in plants punctured by N. tenuis. However, the phytohormones involved in the behavioral responses of T. absoluta could not be identified; therefore, further studies are required. Additionally, all three zoophytophagous mirid predators activated jasmonic acid (JA) signaling pathways, which resulted in the parasitoid Encarsia formosa being attracted to tomato plants. Here, the implications of these results on the efficacy of these three predators as biocontrol agents are discussed.The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under the Grant agreement n°265865 and by the Spanish Ministry of Science and Innovation (AGL2011-30538-C03) and the Conselleria d’Agricultura, Pesca i Alimentació de la Generalitat Valenciana. The authors thank Javier Calvo (KOPPERT BS) for supplying the insects and Universitat Jaume I-SCIC for providing technical support

Orius laevigatus strengthens its role as a biological control agent by inducing plant defenses

Orius laevigatus is a generalist predator that is widely used in augmentative strategies against the key pest of sweet pepper, Frankliniella occidentalis. Despite being a zoophytophagous predator, the phytophagous behavior of O. laevigatus has not been previously explored in depth nor has the impact of phytophagy on plant physiology. Here, the hierarchical significance of O. laevigatus feeding on sweet pepper is compared with other behaviors. O. laevigatus spends the majority of its time (38%) feeding on apical meristems and apical fresh leaves, which were also preferred residence locations. Here, the phytophagous feeding behavior of O. laevigatus on sweet pepper is shown to trigger defensive responses in the plant. These O. laevigatus plant-induced defenses are then shown to contribute to the repellence or attraction of pests or natural enemies, respectively. Specifically, O. laevigatus-punctured sweet pepper plants induce repellency for the whitefly Bemisia tabaci and the thrips species F. occidentalis. In contrast, the whitefly parasitoid Encarsia formosa was significantly attracted to O. laevigatus-punctured plants. The plant responses to O. laevigatus punctures include the release of an altered blend of volatiles and activation of the jasmonic acid and salicylic acid signalling pathways. These results highlight an interesting facet to the biology of O. laevigatus, in which the ability of the predator to induce defensive responses in sweet pepper plants may serve to improve the biological control of both thrips and whiteflies

Correction to: Orius laevigatus strengthens its role as a biological control agent by inducing plant defenses

The authors regret that values of χ2 and P were published incorrectly. Therefore, the authors would like to include the following changes in the published article

Induction of plant defenses: the added value of zoophytophagous predators

Several biological control agents of the hemipteran insect families Miridae, Anthocoridae and Pentatomidae, as well as mites of the family Phytoseiidae are known as zoophytophagous predators, a subset of omnivores, which are primarily predaceous but also feed on plants. It has been recently demonstrated that zoophytophagous predators are capable of inducing defenses in plants through their phytophagy. Despite the vast fundamental knowledge on plant defense mechanisms in response to herbivores, our understanding of defense induction by zoophytophagous predators and applied implications is relatively poor. In this review, we present the physiological basis of the defense mechanisms that these predators activate in plants. Current knowledge on zoophytophagous predator-induced plant defenses is summarized by groups and species for the predators of economic importance. Within each group, feeding habits and the effects of their induced-plant defenses on pests and natural enemies are detailed. Also, the ecological implications of how the induction of defenses mediated by zoophytophagous predators can interact with other plant interactors such as beneficial soil microorganisms and plant viruses are addressed. Based on the above, we propose three approaches to exploit zoophytophagous predator-induced defenses in crop protection and to guide future research. These include using predators as vaccination agents, employing biotechnological approaches, as well as applying elicitors to elicit/mimic predator-induced defenses