Sex-Biased Herbivory and Its Effects on Tritrophic Interactions

Abstract

The dioecious plants are organisms whose sexual organs divided into different individuals of the same species, leading to as a response a difference in the morphology, physiology, and genetics of plants. Although some doubts remain about how the sex of individuals is determined, it has been observed that intraspecific variation, mainly the allocation of nutrients and plant defense, influences the selection of herbivores and higher trophic levels. In the case of herbivory, a preference for male plants has been reported, although the performance and survival of herbivores is not affected. However, recent studies have shown that female plants are also subject to strong herbivory. The most recent investigations evaluating dioecism in plants and their effect at higher trophic levels; in spite of the results with Coleoptera, aphids, and Lepidoptera and different predators (omnivore, parasitoid, and natural enemies), it is not known if it is the sex of the plants or the abundance of herbivores that mediates the interaction. More studies are needed with tropical systems in order to evaluate the role of plant sex on herbivore performance and its effect on the third tropic level and the insect community associated as well. The formation of separate sexes in different individuals has been observed in all animal world. Dioecy in plants is still under investigation in evolutionary and ecological terms because it has several missing data about its origin and maintenance. To what extent intraspecific variation affects the plant and higher trophic levels, and what would be the effect of sex on other guilds? Is it possible to correlate sex and network of interactions that surround it? We hope that these questions, among others, will generate curiosity to know the effect of dioecism.