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Introduction. Many cultivated plants do well with exotic pollinators, and native pollinators can also serve exotic crops. Both can be optimized for agriculture. We studied Nephelium lappaceum L. (Sapindaceae), an andro-dioecious Asian plant, in tropical Mexico. The hermaphrodite flowers were not known to shed viable pollen, and outcrossing from male pollinating plants was thought essential for efficient horticulture. Materials and methods. We used the locally developed CERI61 variety of rambutan and conducted experiments on pollination and fruit yield. An orchard of 1,000 trees was studied intensively during two flowering seasons in Chiapas, Mexico. Plantation yields were recorded for 10 years. We compared open pollination experiments with pollinator exclusion and 'induced pollination' treatments. We caged some trees with colonies of stingless bees: Scaptotrigona and Tetragonisca. Results and discussion. Caged flowers produced fruit, with no male plant present. Pollen dehisced and was viable on approximately 5% of flowers. Trees caged with pollinators, and open pollination treatments revealed 9.1 times more mature fruit than trees without pollinators. Fruit mass was significantly higher in induced pollination treatments. Yields exceeding 7 t ha −1 were obtained during a ten-year test period. Scaptotrigona mexicana (Apidae, Meliponini) was the main pollinator, followed by social halictid bees (Halictus hesperus). Feral Africanized honeybees were not strongly attracted to flowers. Conclusion. Both stingless bee species in open pollination treatments and within cages showed that fruit production increased nearly 10-fold in this variety of rambutan. Although outcrossing versus selfing did not affect initial mature fruit set, a superior fruit yield, in weight and size, was obtained from selfing mediated by pollinators in caged trees.Keywords: Mexico / Chiapas / rambutan (Nephelium lappaceum) / pollinators / Apidae / bees / selfing Corresponding author: isidro.ovando@unach.mx 24Manuel Rincón-Rabanales et al.: Fruits 70 (2015) 23-27 les fleurs de rambutan. Conclusion. L'espèce d'abeille sans dard utilisée tant dans des traitements de pollinisation ouverte que sous cage a contribué à une augmentation proche de 10 fois la récolte de fruits de cette variété de rambutan. Bien que la fécondation croisée n'ait pas affecté la mise à fruit initiale par rapport à l'autofécondation, un rendement supérieur a été obtenu, en poids et en taille de fruits, grâce aux pollinisateurs sur fleurs en cage. Mots clés :Mexique / Chiapas / rambutan (Nephelium lappaceum) / animal pollinisateur / abeilles / autopollinisation

In this work, we studied the main characteristics of flowering, reproductive system and diversity of pollinators for the biofuel plant Jatropha curcas (L.) in a site of tropical southeastern Mexico, within its center of origin. The plants were monoecious with inflorescences of unisexual flowers. The male flowers produced from 3062–5016 pollen grains (266–647 per anther). The plants produced fruits with both geitonogamy and xenogamy, although insect pollination significantly increased the number and quality of fruits. A high diversity of flower visiting insects (36 species) was found, of which nine were classified as efficient pollinators. The native stingless bees Scaptotrigona mexicana (Guérin-Meneville) and Trigona (Tetragonisca) angustula (Latreille) were the most frequent visitors and their presence coincided with the hours when the stigma was receptive. It is noteworthy that the female flowers open before the male flowers, favoring xenogamy, which may explain the high genetic variability reported in J. curcas for this region of the world.

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