Induced Floral and Extrafloral Nectar Production Affect Ant-pollinator Interactions and Plant Fitness Johnattan Hernandez-Cumplido 1 , Bastien Forter 1 , Xoaqu  ın Moreira 2 , Martin Heil 3 , and Betty Benrey 1,4 1 Laboratory of Evolutionary Entomology, Institute of Biology, University of Neuch^ atel, Rue Emile Argand 11, 2000 Neuch^ atel, Switzerland 2 Misi on Biol ogica de Galicia (MBG-CSIC), Apdo. 28, 36080 Pontevedra, Galicia, Spain 3 Departamento de Ingenier  ıa Gen etica, CINVESTAV Irapuato. Km. 9.6 Libramiento Norte, Carretera Irapuato-Le on, 36821 Irapuato, Guanajuato, Mexico ABSTRACT Thousands of plant species throughout tropical and temperate zones secrete extrafloral nectar to attract ants, whose presence provides an indirect defense against herbivores. Extrafloral nectaries are located close to flowers and may modify competition between ants and pollinators. Here, we used Lima bean (Phaseolus lunatus L.) to study the plants interaction between ants and flower visitors and its conse- quences for plant fitness. To test these objectives, we carried out two field experiments in which we manipulated the presence of ants and nectar production via induction with jasmonic acid (JA). We then measured floral and extrafloral nectar production, the number of patrolling ants and flower visitors as well as specific plant fitness traits. Lima bean plants under JA induction produced more nectar in both extrafloral nectaries and flowers, attracted more ants and produced more flowers and seeds than non-induced plants. Despite an increase in floral nectar in JA plants, application of this hormone had no significant effects on flower visitor attraction. Finally, ant pres- ence did not result in a decrease in the number of visits, but our results suggest that ants could negatively affect pollination efficiency. In particular, JA-induced plants without ants produced a greater number of seeds compared with the JA-treated plants with ants. Abstract in Spanish is available with online material. Key words : ant-pollinator conflict; indirect defenses; jasmonic acid; Phaseolus lunatus; seeds. PLANT DEFENSES CAN BE BROADLY CLASSIFIED AS DIRECT OR INDI- RECT (Karban & Baldwin 1997). Plant’ s direct defenses comprise chemical and mechanical traits that deter herbivores, reduce con- sumption, or decrease their survival. Indirect defenses, on the other hand, involve traits that provide shelter, reward, or infor- mation on herbivore presence to natural enemies (predators and parasitoids) that suppress herbivores and in turn, indirectly increase plant biomass and reproduction (Hairston et al. 1960, Schmitz et al. 2000, Romero & Koricheva 2011). Some indirect defenses, such as the production of organic volatile compounds and extrafloral nectar, have been shown to mediate the interaction between herbivores and their natural ene- mies by increasing the likelihood of encounter or by increasing nat- ural enemy density, both of which result in stronger herbivore suppression (Turlings et al. 1990, 1995, Heil 2008, Xiao et al. 2012). Such top-down control of herbivores by natural enemies can result in so called ‘trophic cascades’ and drive an increase in plant bio- mass (i.e., ‘the green world hypothesis’, whereby predators reduce the abundance of herbivores allowing plants to thrive) (Hairston et al. 1960). In particular, extrafloral nectaries (EFN) have been shown to attract predatory ants that defend plants against herbi- vores and increase plant fitness (Heil & Mckey 2003, Rico-Gray & Oliveira 2007, Heil 2008, Chamberlain & Holland 2009). Despite ample evidence for positive effects of predatory ants as an indirect defense for plants (reviewed by Marazzi et al. 2013), some previous studies have found that the presence of ants can also have negative consequences by reducing the number of pollinators visiting flow- ers (Wagner & Kay 2002, Ness 2006, Nicklen & Wagner 2006). For instance, ants can discourage pollination by robbing nectar from the flowers, by attacking pollinators, or simply by patrolling the plant (Galen 1999, Nicklen & Wagner 2006, LeVan et al. 2014). Such antagonistic interactions could result in trade-offs between indirect defenses and pollination (Heil 2002, 2008, Hern andez- Cumplido et al. 2010, Ona & Lochman 2011). Several mechanisms have been suggested to counteract this potential trade-off between pollination and indirect defense by ants (Lach 2008, Ona & Lochman 2011). Plants can produce specific odors that act as repellents against ants. For example, Ghazoul (2001) reported that two acacia-ant mutualists were repelled by floral tissue chemicals from their own host plant spe- cies as well as from 13 other plant genera, showing that ant repellents are widespread. Moreover, plants can also create chemi- cal barriers that deter ants from visiting the flowers (Nicklen & Wagner 2006, Ballantyne & Willmer 2012). Ballantyne & Willmer (2012) documented that at least one-third of 49 plant species in a Costa Rican dry forest were ant-repellent, usually via repellent pollen. Finally, the interaction between ants and pollinators can Received 23 March 2015; revision accepted 26 August 2015. 4 Corresponding author; e-mail: betty.benrey@unine.ch ª 2016 The Association for Tropical Biology and Conservation 1 BIOTROPICA 0(0): 1–7 2016 10.1111/btp.12283