Induced production of extrafloral nectar in intact lima bean plants in response to volatiles from spider mite-infested conspecific plants as a possible indirect defense against spider mites
We found that intact lima bean plants increased the secretion of extrafloral nectar (EFN) after exposure to Tetranychus urticae-induced plant volatiles. Predatory mites, Phytoseiulus persimilis, dispersed more slowly from an exposed intact plant than from a control plant (plant exposed to volatiles from intact conspecific). The predators also dispersed more slowly from those plants that were provided with extra EFN than from untreated plants. We further show that EFN was a potential alternative food source for P. persimilis. From these results, we concluded that increased EFN was involved in the slow dispersal of P. persimilis from the plants exposed to herbivore-induced plant volatiles. Our data suggest that the increase of EFN in an HIPV-exposed intact plant could be an induced indirect defense against spider mites.
KeywordsExtrafloral nectar Herbivore-induced plant volatiles Indirect defense Induced response Plant--plant interactions
We thank Merijn van Tilborg for his comments on the manuscript. This study was supported by CREST of JST (Japan Science and Technology Corporation).
- Raine NE, Willmer P, Stone GN (2002) Spatial structuring and floral avoidance behavior prevent ant-pollinator conflict in Mexican ant-acacia. Ecology 83:3086–3096Google Scholar
- Wickers S (1997) Study of nectariferous secretion in a pioneer plant, Inga thibaudiana, in relation with ants. Acta Bot Gallica 144:315–326Google Scholar