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Summary 1.To assess the effectiveness of extrafloral nectaries (EFN) as a defensive mechanism of plants it is vital to use a multiple interactions approach and assess the contribution of all visiting species and their interactions. 2. The effect of EFN-visiting ants ( Camponotus planatus , C . abdominalis , Conomyrma sp., Crematogaster brevispinosa , Forelius sp., Pseudomyrmex sp.) and wasps ( Polistes instabilis , Polybia occidentalis ) on the reproductive success (estimated as the number of reproductive structures) of Turnera ulmifolia (Turneraceae) was experimentally evaluated. Herbivory effects were tested using Euptoieta hegesia larvae (caterpillars), which is the main herbivore of this plant. The study was done in a coastal sand dune scrub in Veracruz, México. 3. Wasps and ants were selectively excluded using a two-factor design (Wasps, Ants) block design, both factors with two levels (absent, present). The response variables were an index of herbivory per branch and the number of buds, flowers, ripe and unripe fruit per plant, and the seed/fruit ratio per branch. 4. After a week of placing the larvae on experimental plants, they were significantly more frequent on plants where wasps and ants had been experimentally excluded. 5. Wasp presence was associated significantly with greater numbers of buds, flowers, ripe fruit and seeds. When acting separately, wasps and ants exerted a positive effect in decreasing herbivory levels and increasing the number of unripe fruit; when acting together, however, their effect was not additive. 6. This is the first demonstration of a positive effect on the plant by wasps associated with EFN. The ecological implication of this finding is that the function of EFN and the ultimate effects on a plant will probably depend on the array of organisms visiting its EFN.

This paper describes the myrmecochory system of Turnera ulmifolia in a coastal sand dune matorral in Mexico. Turnera ulmifolia has elaiosome-bearing seeds and extrafloral nectaries (EFNs). In ten quadrants (4 ¥ 15 m) antseed interaction was monitored, and an interaction intensity index calculated and correlated with the number of seedlings. Seed removal rates by ants were surveyed every 2 h for 24 h, the ants being observed both on and beneath the plants. The role of the elaiosome in seed removal was evaluated by offering seeds with and without elaiosomes, and elaiosomes only. Finally, the effect of ant manipulation in seed germination was evaluated. There were 25 ant species associated with seeds and/or EFNs, the most frequently recorded being Monomorium cyaneum and Forelius analis . There was a positive correlation between the intensity index and seedling number per quadrant. There was significantly higher mean seed removal during the day than during the night (19.3% and 12.3%, respectively), and from beneath than on the plant (21.9% and 9.5%, respectively). The preference for elaiosomes only was also greater during the diurnal period, and when gathered on, rather than beneath, the plant. Seed manipulation by F. analis enhanced germination by T. ulmifolia . Seed removal, dispersal distances, seed predation and germination were largely determined by ant behaviour. The presence of EFNs may be influencing seed removal on the plant by attracting a specific assemblage of omnivorous ants. Among such assemblages associated with T. ulmifolia we encountered a variety of behaviours, with ant species either good at defending plants but bad at dispersing seeds, or vice versa . We discuss the way in which these two rewards, and the processes involved (defence and dispersion), could have interacted with each other and evolved.

Mexico is one of the most biodiverse countries in the world, with an important proportion of endemism mainly because of the convergence of the Nearctic and Neotropical biogeographic regions, which generate great diversity and species turnover at different spatial scales. However, most of our knowledge of the Mexican ant biota is limited to a few well‐studied taxa, and we lack a comprehensive synthesis of ant biodiversity information. For instance, most of the knowledge available in the literature on Mexican ant fauna refers only to species lists by states, or is focused on only a few regions of the country, which prevents the study of several basic and applied aspects of ants, from diversity and distribution to conservation. Our aims in this data paper are therefore (1) to compile all the information available regarding ants across the Mexican territory, and (2) to identify major patterns in the gathered data set and geographic gaps in order to direct future sampling efforts. All records were obtained from raw data, including both unpublished and published information. After exhaustive filtering and updating information and synonyms, we compiled a total of 21,731 records for 887 ant species distributed throughout Mexico from 1894 to 2018. These records were concentrated mainly in the states of Chiapas (n = 6,902, 32.76%) and Veracruz de Ignacio de la Llave (n = 4,329, 19.92%), which together comprise half the records. The subfamily with the highest number of records was Myrmicinae (n = 10,458 records, 48.12%), followed by Formicinae (n = 3,284, 15.11%) and Ponerinae (n = 1,914, 8.8%). Most ant records were collected in the Neotropical region of the country (n = 12,646, 58.19%), followed by the Mexican transition zone (n = 5,237, 24.09%) and the Nearctic region (n = 3,848, 17.72%). Native species comprised 95.46% of the records (n = 20,745). To the best of our knowledge, this is the most complete data set available to date in the literature for the country. We hope that this compilation will encourage researchers to explore different aspects of the population and community research of ants at different spatial scales, and to aid in the establishment of conservation policies and actions. There are no copyright restrictions. Please cite this data paper when using its data for publications or teaching events.

Ants have been used to assess land use conversion, because they reflect environmental change, and their response to these changes have been useful in the identification of bioindicators. We evaluated ant diversity and composition associated to different land use change in a temperate forest (above 2000 m asl) in Mexico. The study was carried out in "Flor del Bosque" Park a vegetation mosaic of native Oak Forests and introduced Eucalyptus and grasslands. Species richness, dominance and diversity rarefaction curves, based on ant morphospecies and functional groups, were constructed and compared among the three vegetation types, for the rainy and the dry seasons of 2008-2009. Jaccard and Sorensen incidence-based indices were calculated to obtain similarity values among all the habitats. The Oak Forest was a rich dominant community, both in species and functional groups; the Eucalyptus plantation was diverse with low dominance. The most seasonality habitat was the grassland, with low species and high functional group diversity during the dry seasons, but the reverse pattern during the wet season. The Oak Forest was more similar to the Eucalyptus plantation than to the grassland, particularly during the dry season. Oak Forests are dominated by Cold Climate Specialists, specifically Prenolepis imparis (Say). The Eucalyptus and the grassland are characterized by generalized Myrmicinae, as Pheidole spp. and Monomorium ebenium (Forel). The conservation of the native Oak Forest is primordial for the maintenance of Cold Climate Specialist ant communities. The microclimatic conditions in this forest, probably, prevented the invasion by opportunistic species.