Wood Ants

This page is a work in progress. It would be great if anyone wanted to fill-in information here...a complete list of species that are considered wood ants, more information, additional citations...

This is a group of Holarctic Formica species. They form large polydomous colonies and have conspicuous thatch nests. During the warmer months of the year these ants are very active tending arboreal aphids. The size of their nests, the high level of activity of their large workers, the conspiciouos nest mounds and the large number of forest insects they gather from the trees as part of their aphid milking activities have all played a role in wood ants being the subject of research studies over many, many decades. This body of work is largely focused on Palearctic species although there has been some significant studies done with North American wood ants.

Introduction

An edited volume "Wood Ant Ecology and Conservation" was published in 2016. The introductory chapter includes this following synopsis of the group:

Formica rufa nest. Nýrsko, Czech Republic

Few insects in the cool temperate northern hemisphere are as conspicuous as red wood ants. Most red wood ants build large and enduring nest mounds reaching more than 2 m in height, penetrating considerably further beneath the ground surface and thatched on top with a layer of plant material. These mounds are marvels of engineering with a complex array of tunnels and chambers in a carefully controlled environment. Nests may be interlinked, forming, in extreme cases, vast colonies of up to 400 million individual ants covering an area of more than 2.5 km2. Their sheer abundance and collective biomass in temperate forests can rival any mammalian predator.

Red wood ants properly belong to the subgenus Formica sensu stricto or F. rufa group, and can also be commonly referred to as true wood ants, thatch ants or mound ants (hereafter ‘wood ants’). These names derive from the habitat, nesting habit and colour of the adults, which are bicoloured red and brownish-black. Contained within this group of ants are several morphologically and ecologically similar species distributed throughout the Holarctic.

Formica obscuripes. An exceptionally large nest in an unusually forested area (Oregon).

More impressive perhaps than even their numerical dominance is their ecological significance in driving ecosystem processes and function both above and below ground.With a role in predator–prey dynamics, nutrient cycling, seed dispersion, habitat provision and modification, and plant and tree growth, wood ants can truly be described as keystone species. As a result of their ecological importance, wood ants are protected by law in some countries, yet their populations remain threatened from a variety of sources, not least, loss of suitable habitat.

Habitat and distribution Most Palearctic wood ants are associated with heterogeneous coniferous or deciduous forests where canopy gaps allow sunlight to penetrate to the forest floor. Formica truncorum and Formica frontalis are usually found on forest edges and into heathland. The most xerothermic member of the group, Formica pratensis, inhabits both woodland and woodland–steppe habitats. Though species such as Formica prociliata and Formica ferocula can be found in deciduous woodlands,Nearctic species are more generally associated with grassland and shrub steppe habitats. Precise habitat preferences of species can differ across their range.For example, Formica aquilonia in Central Europe is only found between 550 and 2100 m elevation, while at higher latitudes such as in Finland and Scotland, it is rarely found above 550 m. Despite being relatively well studied in some parts of Europe, the distributions of red wood ants are not well known at a global scale.

The areas covered in this book reveal the depth and breadth of research conducted with wood ants.

Chapter 1 - describes species that are currently considered members of the subgenus Formica sensu stricto; their evolution, identification, habitat and distribution
Chapter 2 - reproductive biology and social systems
Chapter 3 - population genetics
Chapter 4 - ecology
Chapter 5- colony and species recognition (Chapter 5), Chapter 6 - interspecific competition (Chapter 6),
Chapter 7, 8 - foraging and interactions with other organisms (Chapters 7 and 8),
Chapter 9 - nutrient cycling (Chapter 9),
Chapter 10- similarities and differences between North American and Eurasian wood ants
Chapter 11, 12 - monitoring and conservation

Parmentier et al. (2018) - These widespread ants are keystone arthropods in European forest ecosystems (Gösswald 1989; Stockan and Robinson 2016). They exert wide-range effects on the forest fauna and flora and drive biogeochemical processes (Wardle et al. 2011). The above ground part of a red wood ant nest is a conspicuous mound of organic thatch (Rosengren et al. 1987), which is tightly regulated and provides an ideal habitat for a diverse community of associated symbionts, known as myrmecophiles (Parmentier et al. 2014). The majority of these red wood ant myrmecophiles directly interact with their host by feeding on their eggs and larvae and stealing prey carried into the nest (Parmentier et al. 2016a).

Species

Nearctic

Paelarctic

References

Ellis, S. and E. J. H. Robinson. 2015. The Role of Non-Foraging Nests in Polydomous Wood Ant Colonies. PLoS ONE. 10(10):e0138321. 17 pp. doi:10.1371/journal.pone.0138321
Parmentier, T., F. De Laender, T. Wenseleers, and D. Bonte. 2018. Contrasting indirect effects of an ant host on prey-predator interactions of symbiotic arthropods. Oecologia. 188:1145-1153. doi:10.1007/s00442-018-4280-6
Sorvari, J. 2018. Wood ant assemblages of Formica rufa group on lake islands and in mainland woodland in Central Finland. Entomologica Fennica. 29:21-29.
Stockan, J. A. and E. J. H. Robinson, editors. 2016. Wood Ant Ecology and Conservation. Cambridge University Press, Cambridge. doi:10.1017/CBO9781107261402