Extrafloral nectary-mediated ant-plant interactions in the coastal vegetation of Veracruz, Mexico:: Richness, occurrence, seasonality, and ant foraging patterns

We studied the extrafloral nectary-mediated ant-plant interactions in the coastal vegetation of Veracruz, Mexico. We surveyed the richness and abundance of interactions, their correlations in both groups, the proportion of associated species and groups, and their temporal and spatial variation. Forty-three plant species (25 families) had extrafloral nectaries, which were more abundant during the wet season. Thirty-one ant species in 18 genera were found in 208 associations with extrafloral nectaries. Sixty-six percent of the nectary-bearing plant species were visited by ants. Eighty-four of the recorded ant species visited nectaries. The proportion of associated species was always higher than that of non-associated species. Ants forage on nectaries day and night, with sympatric species having contrasting foraging schedules. Abundance of nectary-bearing plants differed among seasons, while ant density and richness differed seasonally in specific vegetation types. Abundance of extrafloral nectaries was positively correlated with ant species richness during the rainy season. Seasonal patterns suggest higher nectar availability on vegetative structures during the rainy season and on reproductive structures during the dry season. The high proportion of extrafloral nectary-bearing plants found (14.82%) compared to other surveyed habitats (5-15%) suggests that extrafloral nectary-mediated plant protection by ants is a common feature in coastal communities of Veracruz.