Datapaper: Ants and extrafloral nectary-bearing plants

Extrafloral nectaries (EFNs) are specialized plant glands that secrete nectar but are not related to pollination. Several ants feed on EFNs and, in exchange, they often attack herbivores, reducing the consumption of leaf tissue and floral parts, and enhancing plant performance. Although most empirical studies and reviews have demonstrated that ant visitation benefits EFN-bearing plants, many others have failed to show ants as protective partners. Despite the increasing number of papers dealing with plant defense mediated by EFNs in the last 30 years, there has been no comprehensive effort to synthesize knowledge on this topic. In fact, due to strict inclusion criteria, recent meta-analyses have considered only a small fraction of the published studies on ant–EFN-bearing plant interactions. Therefore, we set out to compile the available published information about ants feeding on EFNs, ranging from descriptive to experimental studies. This dataset includes 342 studies and 4766 records of ants feeding directly on EFNs. When available, we also extracted the outcomes of the interactions from each study. In addition, the effects of ants on herbivory, herbivore abundance, fruit set, and seed set (the response variables with most data) were summarized. The data were gathered from studies published between 1941 and February 2024, across 40 countries and several ecosystems in temperate and tropical zones. Brazil and Mexico were by far the countries with the most records. Ants visiting EFNs were recorded on plants from 30 orders, 65 families, 246 genera, and 441 species. Fabaceae was the family with the greatest number of records (n = 1208, 25.3%), followed by Passifloraceae (n = 430, 9%) and Bignoniaceae (n = 269, 5.6%). Passiflora was the genus with the greatest number of records (n = 254, 5.3%), followed by Chamaecrista (n = 241, 5.1%) and Turnera (n = 176, 3.4%). A total of 7 subfamilies, 82 genera, and 519 ant species were found associated with EFNs. Formicinae was the subfamily with the greatest number of records (n = 1771, 37.2%), followed by Myrmicinae (n = 1609, 33.8%). Camponotus was the genus with the greatest number of records (1173, 24.6%), followed by Crematogaster (n = 518, 10.9%) and Pseudomyrmex (n = 437, 9.2%). The effects of ants on herbivory, herbivore abundance, fruit set, and seed set were explored separately for community- and species-level studies. Ants led to a decrease in herbivory in 67.4% (n = 58) of the community-level studies and in 54.2% (n = 26) of the species-level studies. Similarly, 75.9% (n = 44) and 72.4% (n = 21) of the studies showed a decrease in herbivore abundance caused by ants in community- and species-level studies, respectively. Regarding plant fitness, ants led to an increase in fruit set in 42.9% (n = 21) of the community-level studies and in 52% (n = 13) of the species-level studies. Finally, 47.2% (n = 17) and 42.9% (n = 9) of the studies showed an increase in seed set caused by ants in community- and species-level studies, respectively.