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Cecropia (Urticaceae) trees continuously shed their old large leaves, which fall directly on the forest floor (ground stratum) or accumulate on the aboveground vegetation under Cecropia canopies (vegetation stratum). Since twig-nesting ants are expected to be more nest site limited in the higher forest strata than at ground level, we predict that richness, abundance, and colonization frequency of ant nests in Cecropia petioles are greater in the vegetation stratum when compared with ground stratum. During June 2019, fifteen trees of C. obtusifolia were sampled in a tropical rainforest, in Veracruz, Mexico. For each tree, we collected ten dry fallen petioles per stratum, for 300 petioles in total. We recorded 44 ant nests from 21 ant species. Forty-two nests were found in individual petioles, although in one case a single petiole housed two different ant species. Thirty-four (23%) petioles were colonized in the vegetation stratum and only nine (6%) in the ground stratum. At tree scale, ant nest richness and abundance were significantly greater in the vegetation stratum. Furthermore, frequency of petiole colonization per tree was greater in the vegetation stratum (14 trees; 93.3%) when compared with the ground stratum (5 trees; 33.3%). A stratified pattern of ant occupation in natural nesting sites was observed, supporting that twig-nesting ants are more nest site limited in the upper forest strata than at ground level. Because nesting sites are a limiting resource for arboreal twig-nesting ants, we suggest that Cecropia trees are key components of tropical forests that maintain arboreal ant diversity by promoting nesting sites through dry fallen petioles.

The construction of shelters on plants by arthropods might influence other organisms via changes in colonization, community richness, species composition, and functionality. Arthropods, including beetles, caterpillars, sawflies, spiders, and wasps often interact with host plants via the construction of shelters, building a variety of structures such as leaf ties, tents, rolls, and bags; leaf and stem galls, and hollowed out stems. Such constructs might have both an adaptive value in terms of protection (i.e., serve as shelters) but may also exert a strong influence on terrestrial community diversity in the engineered and neighboring hosts via colonization by secondary occupants. Although different traits of the host plant (e.g., physical, chemical, and architectural features) may affect the potential for ecosystem engineering by insects, such effects have been, to a certain degree, overlooked. Further analyses of how plant traits affect the occurrence of shelters may therefore enrich our understanding of the organizing principles of plant-based communities. This data set includes more than 1000 unique records of ecosystem engineering by arthropods, in the form of structures built on plants. All records have been published in the literature, and span both natural structures (91% of the records) and structures artificially created by researchers (9% of the records). The data were gathered between 1932 and 2021, across more than 50 countries and several ecosystems, ranging from polar to tropical zones. In addition to data on host plants and engineers, we aggregated data on the type of constructs and the identity of inquilines using these structures. This data set highlights the importance of these subtle structures for the organization of terrestrial arthropod communities, enabling hypotheses testing in ecological studies addressing ecosystem engineering and facilitation mediated by constructs. There are no copyright restrictions and please cite this paper when using the data in publications.

Understanding the factors that influence the composition and structure of bee communities in natural habitats is critical for conservation and restoration efforts, mainly in disturbed ecosystems that are widely used for agricultural crop production, such as tropical dry forests (TDF). The aim of this study was to evaluate the effects of tree species composition and vegetation structure on the composition, abundance and species richness of eusocial and non-eusocial wild bee assemblages. Bees (19.909 individuals of 96 species) were collected in fifteen plots in different secondary succession stages in a TDF in the state of Minas Gerais, Brazil. We found a positive relationship between tree community similarity and bee community similarity, for both eusocial and non-eusocial bees. Average tree height positively affected the abundance and species richness of eusocial bees, while the abundance of non-eusocial bees was negatively affected by tree species richness. Similar tree species composition and vegetation structure between plots at the same stage of secondary succession probably determined more similar bee communities than dissimilar tree communities. Most eusocial bee species are dependent on cavities in large trees to house their colonies, while most non-eusocial bees probably prefer open habitats because they provide a greater density and diversity of floral resources, and suitable areas for ground-nesting species. Since eusocial bees represented 94% of the individuals sampled, the conservation and restoration of mature forests is of primary importance in order to increase eusocial bee diversity, and the maintenance of these areas in the vicinity of agricultural systems is crucial to increase the ecosystem service of pollination.

Oncideres albomarginata chamela (Cerambycidae: Lamiinae) is a stem-boring beetle that girdles branches of Spondias purpurea (Anacardiaceae) for oviposition. Many beetles opportunistically oviposit in these branches and larvae create cavities that are abandoned when the adults emerge. Our objective was to evaluate the role of wood-boring beetles in promoting ant nest cavities mediated by a twig-girdler engineer. We collected 120 abandoned branches that had been detached by O. albomarginata chamela , in a tropical dry forest, in Jalisco, Mexico. Sixty abandoned branches were placed in trees from February to April, and another sixty from August to October 2016. In order to test the effects of nest characteristics on ant species, we measured the diameter of each branch and the diameter of the ant nest entrance as explanatory variables, whereas the size of ant species was used as response variable. We found 49 nests of arboreal ants from 14 species. The body size of the ants nesting in the abandoned branches was positively correlated with the diameter of the nest entrance. Ants used abandoned branches mainly as polydomic nests. Our result confirms that ants partitioning resources according to the size of entrance holes made by wood-boring beetles in dead wood. Polydomic nests have been reported as a strategy to promote the colonization of new nesting sites and the reduction of intraspecific competition. We conclude that the ecosystem engineering carried out by the twig-girdler O. albomarginata chamela had extended effects on the arboreal ant community, that takes advantage of the cavities abandoned by wood-boring beetles for nesting, especially for polydomic nests.