A globally integrated structure of taxonomy to support biodiversity science and conservation.

All aspects of biodiversity research, from taxonomy to conservation, rely on data associated with species names. Effective integration of names across multiple fields is paramount and depends on the coordination and organization of taxonomic data. We assess current efforts and find that even key applications for well-studied taxa still lack commonality in taxonomic information required for integration. We identify essential taxonomic elements from our interoperability assessment to support improved access and integration of taxonomic data. A stronger focus on these elements has the potential to involve taxonomic communities in biodiversity science and overcome broken linkages currently limiting research capacity. We encourage a community effort to democratize taxonomic expertise and language in order to facilitate maximum interoperability and integration.

Six decades of museum collections reveal disruption of native ant assemblages by introduced species.

There is a looming environmental crisis characterized by widespread declines in global biodiversity,1,2,3,4,5,6 coupled with the establishment of introduced species at accelerated rates.7,8,9,10,11,12,13,14 We quantified how multi-species invasions affect litter ant communities in natural ecosystems by leveraging museum records and contemporary collections to assemble a large (18,990 occurrences, 6,483 sampled local communities, and 177 species) 54-year (1965-2019) dataset for the entire state of Florida, USA. Nine of ten species that decreased most strongly in relative abundance ("losers") were native, while nine of the top ten "winners" were introduced species. These changes led to shifts in the composition of rare and common species: in 1965, only two of the ten most common ants were introduced, whereas by 2019, six of ten were introduced species. Native losers included seed dispersers and specialist predators, suggesting a potential loss of ecosystem function through time, despite no obvious loss of phylogenetic diversity. We also examined the role of species-level traits as predictors of invasion success. Introduced species were more likely to be polygynous than native species. The tendency to form supercolonies, where workers from separate nests integrate, also differed between native and introduced species and was correlated with the degree to which species increased in their rank abundances over 50 years. In Florida, introduced ants now account for 30% of occurrence records, and up to 70% in southern Florida. If current trends continue, introduced species will account for over half of occurrence records in all Florida's litter ant communities within the next 50 years.

The ant genus Strumigenys Smith, 1860 (Hymenoptera: Formicidae) in western North America North of Mexico.

Strumigenys is a globally distributed genus of mostly cryptic leaf-litter ants. In North America they are common throughout eastern deciduous forests but become increasingly rare to the west. Here I review the Strumigenys fauna of western North America north of the Mexico border including all states west of the eastern border of Texas. Six new native species with ranges entirely within this region are described: S. collinsae sp. nov., S. macgowni sp. nov., S. mendezi sp. nov., S. moreauviae sp. nov., S. lucky sp. nov., and S. subtilis sp. nov. Strumigenys ananeotes Longino Booher 2019 is given a more thorough description, and S. alberti Forel 1893, a Neotropical species, is reported from the region for the first time. All new species bear clear morphological relationships with a native North American clade of smithistrumiform species. I include species accounts and provide an illustrated key for all species of this region.

A new species group of Strumigenys (Hymenoptera, Formicidae) from Ecuador, with a description of its mandible morphology.

Strumigenys is one of the most diverse ant genera in the world and arguably the most morphologically diverse, exhibiting an exceptional range of mandible shape and function. A new species, Strumigenys ayersthey sp. nov., discovered in the Chocó region of Ecuador is described. With two morphological characters, this species is shown to be a morphologically unique outlier among Strumigenys globally, having predominately smooth and shining cuticle surface sculpturing and long trap-jaw mandibles. Using µCT scans, we produced 3D images of the worker ant and static images to examine and compare mandible articular morphologies with most morphologically similar members of the mandibularis species group. Cuticular, pilosity, and articular mandible morphological differences supports placing the new species in its own new species group.

Functional innovation promotes diversification of form in the evolution of an ultrafast trap-jaw mechanism in ants.

Evolutionary innovations underlie the rise of diversity and complexity-the 2 long-term trends in the history of life. How does natural selection redesign multiple interacting parts to achieve a new emergent function? We investigated the evolution of a biomechanical innovation, the latch-spring mechanism of trap-jaw ants, to address 2 outstanding evolutionary problems: how form and function change in a system during the evolution of new complex traits, and whether such innovations and the diversity they beget are repeatable in time and space. Using a new phylogenetic reconstruction of 470 species, and X-ray microtomography and high-speed videography of representative taxa, we found the trap-jaw mechanism evolved independently 7 to 10 times in a single ant genus (Strumigenys), resulting in the repeated evolution of diverse forms on different continents. The trap mechanism facilitates a 6 to 7 order of magnitude greater mandible acceleration relative to simpler ancestors, currently the fastest recorded acceleration of a resettable animal movement. We found that most morphological diversification occurred after evolution of latch-spring mechanisms, which evolved via minor realignments of mouthpart structures. This finding, whereby incremental changes in form lead to a change of function, followed by large morphological reorganization around the new function, provides a model for understanding the evolution of complex biomechanical traits, as well as insights into why such innovations often happen repeatedly.

Taxonomic clarification of two Nearctic Strumigenys (Hymenoptera: Formicidae).

In 1901, Forel described an ant species from a relatively poorly known genus of ants from North America, naming it Strumigenys pilinasis. In 1931 M. R. Smith obtained the holotype and redescribed it, and he included a first illustration. The description was incomplete and the illustration resembled Strumigenys brevisetosa Smith, 1935, more than it resembled S. pilinasis, which led subsequent taxonomists to make consistent misidentifications and to consider S. brevisetosa to be a synonym of S. pilinasis. Here I redescribe both S. pilinasis and S. brevisetosa (revived status). Strumigenys manni Wesson Wesson, 1939, and S. ohioensis Kennedy Schramm, 1933, are new junior synonyms of S. pilinasis, and S medialis Kennedy Schramm, 1933, is a new junior synonym of S. brevisetosa.

A taxonomic revision of the Strumigenys nitens and simulans groups (Hymenoptera: Formicidae), two Caribbean radiations of leaf litter ants.

In this study, we revise two groups of cryptic leaf litter ants, the Strumigenys nitens and Strumigenys simulans species groups. These two groups are restricted to the Greater Antilles and the Bahamas. We redefine the species groups, provide a key for the five species in the S. nitens group, and differentiate the two species in the S. simulans group. Four new species are described: Strumigenys caiman sp. nov., S. economoi sp. nov., S. hubbewatyorum sp. nov., and S. zemi sp. nov. We review and provide a key for the Strumigenys fauna of Hispaniola, which comprises the two endemic species S. economoi and S. zemi, six more broadly distributed Neotropical species, and three pan-tropical "tramp" species.