Many studies have focused on the impacts of climate change on biological assemblages, yet little is known about how climate interacts with other major anthropogenic influences on biodiversity, such as habitat disturbance. Using a unique global database of 1128 local ant assemblages, we examined whether climate mediates the effects of habitat disturbance on assemblage structure at a global scale. Species richness and evenness were associated positively with temperature, and negatively with disturbance. However, the interaction among temperature, precipitation and disturbance shaped species richness and evenness. The effect was manifested through a failure of species richness to increase substantially with temperature in transformed habitats at low precipitation. At low precipitation levels, evenness increased with temperature in undisturbed sites, peaked at medium temperatures in disturbed sites and remained low in transformed sites. In warmer climates with lower rainfall, the effects of increasing disturbance on species richness and evenness were akin to decreases in temperature of up to 98C. Anthropogenic disturbance and ongoing climate change may interact in complicated ways to shape the structure of assemblages, with hot, arid environments likely to be at greatest risk.

What forces structure ecological assemblages? A key limitation to general insights about assemblage structure is the availability of data that are collected at a small spatial grain (local assemblages) and a large spatial extent (global coverage). Here, we present published and unpublished data from 51 ,388 ant abundance and occurrence records of more than 2,693 species and 7,953 morphospecies from local assemblages collected at 4,212 locations around the world. Ants were selected because they are diverse and abundant globally, comprise a large fraction of animal biomass in most terrestrial communities, and are key contributors to a range of ecosystem functions. Data were collected between 1949 and 2014, and include, for each geo‐referenced sampling site, both the identity of the ants collected and details of sampling design, habitat type, and degree of disturbance. The aim of compiling this data set was to provide comprehensive species abundance data in order to test relationships between assemblage structure and environmental and biogeographic factors. Data were collected using a variety of standardized methods, such as pitfall and Winkler traps, and will be valuable for studies investigating large‐scale forces structuring local assemblages. Understanding such relationships is particularly critical under current rates of global change. We encourage authors holding additional data on systematically collected ant assemblages, especially those in dry and cold, and remote areas, to contact us and contribute their data to this growing data set.

In insect societies, chemical communication plays an important role in colony reproduction and individual social status. Many studies have indicated that cuticular hydrocarbons (CHCs) are the main chemical compounds encoding reproductive status. However, these studies have largely focused on queenless or monogynous species whose workers are capable of egg laying and have mainly explored the mechanisms underlying queen-worker or worker-worker reproductive conflicts. Less is known about what occurs in highly polygynous ant species with permanently sterile workers. Here, we used the Argentine ant as a model to examine the role of CHCs in communicating reproductive information in such insect societies. The Argentine ant is unicolonial, highly polygynous, and polydomous. We identified several CHCs whose presence and levels were correlated with queen age, reproductive status, and fertility. Our results also provide new insights into queen executions in the Argentine ant, a distinctive feature displayed by this species in its introduced range. Each spring, just before new sexuals appear, workers eliminate up to 90% of the mated queens in their colonies. We discovered that queens that survived execution had different CHC profiles from queens present before and during execution. More specifically, levels of some CHCs were higher in the survivors, suggesting that workers could eliminate queens based on their chemical profiles. In addition, queen CHC profiles differed based on season and species range (native vs. introduced). Overall, the results of this study provide new evidence that CHCs serve as queen signals and do more than just regulate worker reproduction.

The dynamic in Argentine ant colonies varies seasonally, influenced by biotic and abiotic factors. In winter the spatial range of the colony is contracted in large formations (winter nests) containing a large number of queens and workers. Winter nests are the clue to the species' dispersion power and the invasion of new habitats. For this reason a yearly elimination of queens and workers in winter at the edge (front) of the invasion could be a useful tool for weakening the species' dispersion and therefore limiting its establishment in new areas. Here, we determined the spatial dynamics of the Argentine ant nests during 1 year, and we assessed the invasion management by means of manual removal of winter nests for two consecutive winters, determining its effects during the following 3 years. We mapped nests found in 18 plots divided into two groups: extirpated (with removal of nests) and non-extirpated (control), along the fronts of three locations. Seasonal variation in the abundance of nests and workers, together with the two-year extirpation effects were evaluated. We found that colonies tended to follow an annual cycle of contraction and dispersion, with a decrease in the number of nests as we approached the invasion front. The extirpation was effective only in the front area, where it promoted smaller, less lasting and aggregated nests, as well as a decrease in the abundance of queens and workers. Nests also experienced a decrease during the two first winters but a recovery in the third, when no extirpation was done. Thus, a yearly perturbation should be performed to keep the expansion of the Argentine ant at a low rate, and to limit its establishment in new areasThis work was financed by the Spanish Ministry of Science and Innovation with the support of a predoctoral grant (BES-2008-005102) associated with research projects MEC/FEDER2007-64080-C02-02/BOS and CGL2010-16451, and a FI grant from the European Social Fund and the DIUE of the Autonomous Government of Catalonia in support of ML

The Argentine ant is an invasive species that has been introduced worldwide causing devastating effects on entire ecosystems. Control strategies might be focused on slowing its rate of spread to limit its establishment inside yet non-invaded areas. For this, a better knowledge about nest selection is necessary to identify rapidly and accurately nest locations where to apply control measures. Herein, nest site selection by the Argentine ant, nests' physical characteristics and their longevity were studied in three invaded cork oak secondary forest. Results showed that this species shifts nest locations seasonally to keep appropriate microclimatic conditions, nesting mainly underneath rocks during cold and rainy months and in tree bases during warmer periods. The terrain features at micro-scale (orientation and slope) were found to influence the distribution of the Argentine ant nests beneath rocks. Additionally, artificial nests used as a control tool were tested, finding that their use may be suitable if they are set in appropriate locations and before the ants start migrating to winter aggregationsFinancial support was provided by the Spanish Ministry of Science and Education, with the associated projects CGL2007-64080-C02/BOS and CGL2010-16451/BOS, and the pre-doctoral grant BES-2008-372 005102 in support to M