ORIGINAL CONTRIBUTION Nutritional variations at Nesidiocoris tenuis feeding sites and reciprocal interactions between the mirid and tomato plants J. A. Sanchez, F. M. del Amor, P. Flores & E. L opez-Gallego Instituto Murciano de Investigaci  on y Desarrollo Agrario y Alimentario (IMIDA), Murcia, Spain Keywords amino acids, behaviour, extra oral digestion, life history, mirids, omnivores, phytophagy, plant defence, sugars Correspondence Juan Antonio S anchez (corresponding author), Dpto. Biotecnolog  ıa y Protecci on de Cultivos, Instituto Murciano de Investigaci  on y Desarrollo Agrario y Alimentario (IMIDA), C/Mayor, 1. La Alberca, 30150 Murcia, Spain. E-mail: Juana.sanchez23@carm.es Received: November 27, 2014; accepted: May 20, 2015. doi: 10.1111/jen.12246 Abstract Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae) uses a flush-and-lacerate feeding strategy producing necrotic rings (NR) at feeding sites in tomato plants. The aim was to investigate the variation in the concentrations of amino acids (aa) and sugars at feeding sites, and its effect on this mirid’s life-history traits and behaviour. The concentration of nutrients was mea- sured in different parts of stems damaged by N. tenuis and mechanically using liquid chromatography. aa concentrations increased below NR; around and above NR, the concentrations of essential and non-essential aa declined. The concentration of glucose was lower around NR and below. The change in the distribution of aa was similar in NR and mechanically damaged stems, whereas there were no differences in sugar contents. Development time and nymphal mortality were measured on fresh leaflets, leaflets with NR and leaflets plus Ephestia kuehniella Zeller (Lepidoptera: Pyralidae). Without prey, development took longer on NR than on fresh leaflets. Development was quicker and mortality lower on leaflets plus moth eggs. Finally, behavioural events were recorded in fifth- instar nymphs of N. tenuis in: (i) double-choice experiments (DCE) using leaflets with and without NR; (ii) DCE using leaflets exposed and non-pre- viously exposed to nymphs and (iii) fresh tomato leaflets plus Bemisia tab- aci (Gennadius) (Hemiptera: Aleyrodidae) nymphs. In (i), feeding events lasted longer at NR sites; in (ii), the behaviour of the nymphs on previ- ously exposed leaflets was not significantly different from fresh leaflets; and in (iii), most of the time was dedicated to prey feeding. The overall results indicate that N. tenuis do not take advantage of the inhibited trans- location of nutrients in the phloem. The poorer performance of nymphs on leaflets from plants previously exposed to N. tenuis might be due to a general decrease in the concentration of nutrients or to the activation of plant defences. Introduction Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae) is an omnivorous mirid common in tomato crops in the Mediterranean (Perdikis et al. 2008; Zappala et al. 2013). In the absence of prey, N. tenuis phytophagy increases exponentially, but the mirid’s fitness is greatly reduced in comparison to feeding on animal prey (Urbaneja et al. 2005; Sanchez 2008, 2009; Calvo et al. 2009). Hemipterans use extraoral digestion, injecting saliva with digestive enzymes and lacerating tissues with the stylets to liquefy solid nutrients before ingestion (Miles 1972; Cohen 1995, 1998). Nesidiocoris tenuis produces characteristic necrotic rings, which ini- tially start as a depression and whitening of affected areas, before swelling and browning. Phytophagous insects may induce changes in the morphology and chemistry of plants, with subsequent effects on their own performance (e.g. growth, reproduction and sur- vival) and that of other species(Mayer et al. 2002; J. Appl. Entomol. 140 (2016) 161–173 © 2015 Blackwell Verlag GmbH 161 J. Appl. Entomol.