Combination of generalist predators, Nesidiocoris tenuis and Macrolophus pygmaeus, with a companion plant, Sesamum indicum: What benefit for biological control of Tuta absoluta?

Abstract

Tuta absoluta is one of the most damaging pests of tomato crops worldwide. Damage due to larvae may cause up to 100% loss of tomato production. Use of natural enemies to control the pest, notably predatory mirids such as Nesidiocoris tenuis and Macrolophus pygmaeus, is increasingly being promoted. However, considering the potential damage caused to tomatoes by these omnivorous predators in the absence of T. absoluta, an alternative solution could be required to reduce tomato damage and improve the predators’ performance. The use of companion plants can be an innovative solution to cope with these issues. The present study aimed to determine the influence of companion plants and alternative preys on the predators’ performance in controlling T. absoluta and protecting tomato plants. We evaluated the effect of predators (alone or combined) and a companion plant (sesame (Sesamum indicum)) on T. absoluta egg predation and crop damage caused by N. tenuis. The influence of an alternative prey (Ephestia kuehniella eggs) on the spatial distribution of predators was also evaluated by caging them in the prey presence or absence, either on tomato or sesame plants or on both. We found that the presence of sesame did not reduce the efficacy of N. tenuis or M. pygmaeus in consuming T. absoluta eggs; hatched egg proportion decreased when N. tenuis, M. pygmaeus, or both predators were present. More specifically, this proportion was more strongly reduced when both predators were combined. Sesame presence also reduced necrotic rings caused by N. tenuis on tomato plants. Nesidiocoris tenuis preferred sesame over tomato plants (except when food was provided only on the tomato plant) and the upper part of the plants, whereas M. pygmaeus preferred tomato to sesame plants (except when food was provided only on the sesame plant) and had no preference for a plant part. Combination of predators N. tenuis and M. pygmaeus allows for better coverage of cultivated plants in terms of occupation of different plant parts and better regulation of T. absoluta populations. Sesamum indicum is a potential companion plant that can be used to significantly reduce N. tenuis damage to tomatoes.

Sesame as an Alternative Host Plant to Establish and Retain Predatory Mirids in Open-Field Tomatoes

“…Nesidiocoris tenuis can reproduce on sesame in the absence of prey [ 40 ]. In cage studies, the combination of sesame and tomato increased N. tenuis populations without increasing damage to the tomatoes [ 17 , 28 , 31 ]. This study showed that the benefits previously seen with T. absoluta when mirids, N. tenuis and Macrolophus pygmaeus , were confined to a cage [ 31 ] could also work to control B. tabaci in open-field production where the mirids could leave the crop.…”

“…In cage studies, the combination of sesame and tomato increased N. tenuis populations without increasing damage to the tomatoes [ 17 , 28 , 31 ]. This study showed that the benefits previously seen with T. absoluta when mirids, N. tenuis and Macrolophus pygmaeus , were confined to a cage [ 31 ] could also work to control B. tabaci in open-field production where the mirids could leave the crop. When given the ability to move freely in the field, N. tenuis did not remain on sesame despite the presence of whiteflies and being a better plant resource than tomato [ 27 ].…”

“…When confined in greenhouses, N. tenuis can become a pest of tomatoes when prey is scarce by causing necrotic rings that can lead to plant stunting, flower abortion, and, ultimately, reduced yield [ 26 ]. Management strategies based on selective pesticide applications, the addition of supplemental food, and companion planting with sesame [ Sesamum indicum L. (Lamiales; Pedaliaceae)] have been developed to lessen the mirids’ negative impact and to enhance their establishment in protected tomatoes [ 27 , 28 , 29 , 30 , 31 ]. Another approach has been to use other mirid species, such as Macrolophus spp.…”

Non-host plant odors influence the tritrophic interaction between tomato, its foliar herbivore Tuta absoluta and mirid predator Nesidiocoris tenuis

“…Among the key predators of T. absoluta are the zoophytophagous mirids such as Macrolophus pygmaeus (Hemiptera: Miridae), native to Europe and N. tenuis (Hemiptera: Miridae), native to the Mediterranean coast ( Sanchez et al., 2006 ; Sanchez et al., 2009 ; van Lenteren, 2012 ; Zappalà et al., 2013 ; Lins et al., 2014 ; Sanchez et al., 2018 ; Ayelo et al., 2021 ). For example, in a greenhouse tomato production study in Europe, M.pygmaeus was found to significantly reduced the population of whiteflies Bemisia tabaci and T. absoluta galleries ( Sanchez et al., 2018 ; Konan et al., 2021 ). These predators prey on eggs and lower instars of other small arthropods such as aphids, spider mites, and thrips ( van Lenteren, 2012 ; Zappalà et al., 2013 ; Sylla et al., 2016 ; Biondi et al., 2018 ).…”

“…These predators prey on eggs and lower instars of other small arthropods such as aphids, spider mites, and thrips ( van Lenteren, 2012 ; Zappalà et al., 2013 ; Sylla et al., 2016 ; Biondi et al., 2018 ). In the absence of sufficient prey, they feed on leaf mesophylls, ground tissues of stems, inflorescences, and fruits of host plants resulting in significant yield reduction ( Moerkens et al., 2016 ; Sanchez et al., 2018 ; Konan et al., 2021 ). Previous studies have demonstrated that the availability of diverse food sources for generalist natural enemies in heterogeneous habitats reduced damage to host plants and attracted more predators compared to monocultures ( Tang et al., 2013 ; Grez et al., 2014 ).…”