Abstract
Plant defensive substances can affect the quality of herbivores as prey for predators either directly or indirectly. Directly when the prey has become toxic since it ingested toxic plant material and indirectly when these defences have affected the size and/or nutritional value (both quality parameters) of prey or their abundance. To disentangle direct and indirect effects of JA-defences on prey quality for predators, we used larvae of the omnivorous thrips Frankliniella occidentalis because these are not directly affected by the jasmonate-(JA)-regulated defences of tomato. We offered these thrips larvae the eggs of spider mites (Tetranychus urticae or T. evansi) that had been feeding from either normal tomato plants, JA-impaired plants, or plants treated with JA to artificially boost defences and assessed their performance. Thrips development and survival was reduced on the diet of T. evansi eggs relative to the diet of T. urticae eggs yet these effects were independent from the absence/presence of JA-defences. This indicates that the detrimental effects of tomato JA-defences on herbivores not necessarily also affects their quality as prey.
Highlights
Plants have evolved a multitude of defence traits to resist being consumed
To verify that larvae of our F. occidentalis strain are tolerant to jasmonic acid (JA) defences, we quantified the amounts of feeding damage they had inflicted on leaf tissue of wild type (WT), def-1, JA-treated def-1 and PS plants (Fig. 2)
To assess the extent to which thrips larvae are affected by indirect effects of plant JA-defences - i.e. via changes in the nutritional value and/or size of their prey - we offered eggs produced by spider mites on either WT (‘induced eggs’), def-1 (‘uninduced eggs’) or JA-treated def-1 tomato plants (‘boosted eggs’) as prey items to our JA-defence-tolerant thrips larvae on leaf discs of sweet pepper plants, i.e. a poor-quality host plant
Summary
Plants have evolved a multitude of defence traits to resist being consumed. Some of these defences are constitutive, i.e. traits displayed irrespective of the presence of herbivores or pathogens, while others are induced, i.e. traits displayed upon attack[1,2]. To assess the indirect effects of plant defences on prey quality we made use of the omnivore Frankliniella occidentalis. This species is a worldwide pest on ornamental plants and crops as it has a short generation time, high fecundity, great dispersal potential, and readily feeds from leaves, flowers and pollen of multiple plant species as well as on egg-, juvenile- and adult stages of various predators[46,47] and herbivores, including spider mites[48]. While adult F. occidentalis appeared to be sensitive to these naturally induced JA-defences[49,51], their larvae appeared to tolerate these defences - unless these were artificially boosted[6,52]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
