- Range elevation
- 800 to 3194 m
- 2624.67 to 10479.00 ft
- Range length
- 4.0 to 7.5 mm
- 0.16 to 0.30 in
- Development - Life Cycle
- Mating System
- Key Reproductive Features
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- Breeding interval
- Females mate once during the nuptial flight, while males may mate several times.
- Breeding season
- Nuptial flights occur in June and July.
- Parental Investment
Most workers live 19 to 44 days after reaching adulthood, an average of 31.6 days, though some overwinter and live more than a year. (Conway, 1996a)
- Range lifespan
- 1+ (high) years
- Range lifespan
- Typical lifespan
- 19 to 44 days
- Typical lifespan
Western thatching ants get their name from the piles of thatch they constructs to cover their nest mounds. The thatch is created from seeds, twigs, plant stems, grass, and soil. Piles of thatch can be several centimeters to a meter deep and several centimeters to 1.5 m across. This thatch keeps nests at a constant temperature throughout the day, even though nests are typically constructed out in the open in dry, warm regions. Workers are constantly repairing and adding to the thatch. Many mounds are also built around the main stem of plants such as sagebrush. Ants chew the bark on the stem and spray formic acid at it until it dies, at which point it can be removed, creating a central passage in the center of the nest. (Conway, 1996a; Conway, 1997; Herbers, 1979; McIver and Steen, 1994; Mico, et al., 2000; Weber, 1935)is polydomous, with one colony typically living in several mounds. Colonies often switch primary nests. New colonies are formed by budding. Secondary mounds may become primary nests, or new mounds may be created nearby, with workers moving between the mounds.
Mound usage by the colony can change throughout the day and year. A nest can have anywhere from 1 to 52 entrances, and these entrances constantly change. During warmer parts of the day, ants use entrances that are under cover and use entrances that are in the sun during the morning and evening. The same principle applies to trail usage. Most trails are constructed under cover of vegetation, rarely veering out into the open. Ants will also remain in the nest or secondary nest during the hottest part of the day, with most foraging taking place during the morning and evening. Many colonies have secondary nests. These nests are typically constructed at the base of the plants where workers farm aphids. Workers use this secondary nest throughout the day, the largest number take shelter in the mid-afternoon during the warmest temperatures. There are two types of workers involved in honeydew farming, tenders and transporters. Transporters spend much of the day in the secondary nest, while the tenders farm honeydew and bring the honeydew to the transporters. The transporters collect the honeydew in their crop from the tenders and return to the nest with the honeydew. (Conway, 1996a; Conway, 1997; Herbers, 1979; McIver and Steen, 1994; Mico, et al., 2000; Weber, 1935)
Communication and Perception
Antennae are one of their most important sensory organs, used for olfaction, chemical detection, and tactile perception. Myrmecophilus manni) live in nests and have learned to mimic their antennae movements, which allows crickets to antennate with ants and remain undetected as non-colony members. When foraging at extra floral nectaries, ants can communicate with other foragers. If an ant finds a depleted nectary, it leaves a drop of liquid at the junction of the main stem and the stem to the depleted nectary. When another ant moves along the stem, it will antennate the drop of liquid and move past the depleted nectary without having to investigate itself. Females release pheromones into the air during mating to attract males. As males swarm over the plants where the females wait, females also move their body and antennae to signal their location, indicating that vision is important in perceiving other individuals. (Conway, 1996b; Henderson and Akre, 1986; Talbot, 1972; Tilman, 1978)communicates with other workers by antennation and also perceives their environment with their antennae. Ant crickets (
- Other Communication Modes
orthopterans, beetles, terrestrial isopods, hemipterans, lepidopteran larvae, dipterans, and other ants. It also scavenges dead insects and other invertebrates. Foraging ants bring both living and dead insects back to the nest. also eats organic matter, nectar from extra floral nectaries, and plant tissues including leaves, galls, and flowers. It has been recorded scavenging seeds, eating the edible part and storing the rest in the nest. Occasionally, these ants also feed on carrion, such as dead rattlesnakes, birds, and small mammals. Ants typically collect liquid from the carcasses and store it in their crops, returning to the nest and regurgitating the liquid via trophallaxis. also farms honeydew from honeydew-producing insects, including aphids and membracids. Honeydew is an important component of their diet, as a significant source of amino acids, carbohydrates, and water. It provides energy for the workers, and nutrients for the brood and queen. These ants occasionally also prey on the insects that they tend. (Beattie and Culver, 1977; Billick and Carter, 2007; Clark and Blom, 1991; Conway, 1997; Erickson, et al., 2012; Heikkinen, 1999; McIver and Yandell, 1998; McIver, et al., 1997; Tilman, 1978)is an omnivore. It preys on many species of insects, particularly
- Primary Diet
- Animal Foods
- terrestrial non-insect arthropods
- Plant Foods
- seeds, grains, and nuts
- Other Foods
There are a variety of predators of Ant crickets usually live peacefully in the nest, but have been observed attacking larvae. Another ant species, Leptothorax hirticornis, may eat larvae if it gets in the nests and will also attack and eat isolated workers. Many species of spiders are also predators. Many bird species, including eastern kingbirds, western kingbirds, flickers, and American crows feed on . Toads are also predators, including Canadian toads and Woodhouse's toads. Bears have also been known to dig open nests to feed. (Conway, 1996a; Conway, 1997; Heikkinen, 1999; Henderson and Akre, 1986; McIver, et al., 1997; Weber, 1935). As predators themselves, they are aggressive and defend their brood and the aphids that they tend. They can spray formic acid when threatened or attacked. Other insects that gain entry to the nest can pose a threat to the brood.
- Known Predators
- ants (Leptothorax hirticornis)
- cricket ants (Myrmecophilus manni)
- spiders (Araneae)
- eastern kingbirds (Tyrannus tyrannus)
- western kingbirds (Tyrannus verticalis)
- flickers (Colaptes auratus borealis)
- American crows (Corvus brachyrhynchos)
- Canadian toads (Anaxyrus hemiophrys)
- Woodhouse's toad (Bufo woodhousei)
- bears (Ursidae)
aphids that it tend includes Pleotrichophorus utensis, Uroleucon escalantii, and Lachnus allegheniensis, as well as members of the following genera Aphis, Macrosiphum, Pleotrichophorus, and many more. It tends honeydew producing membracids, as well as some jumping plant lice, scale insects, mealybugs, and gall wasps. Thatch nests of provide shelter to many species of insects and other Arthropods without directly impacting the ants. One such insect is the beetle Euphoriaspis hirtipes. All life stages of this beetle can be found within the thatch. The exact relationship is uncertain, as the ants do not seem to get anything out of the beetles presence and do not even seem to notice them. The beetles can also survive in the thatch without the ants. Other Arthropods found in the thatch and nest of include pseudoscorpians, springtails, hemipterans, dipterans, and other beetle species. Larvae of these Arthropods often use the thatch or chambers in the nest for hibernation or development and feed on decaying matter. The ants largely ignore them. (Conway, 1997; Erickson, et al., 2012; Grinath, et al., 2012; Henderson and Akre, 1986; Mico, et al., 2000; Risch, et al., 2008; Seibert, 1992; Seibert, 1993)is a mutualist with many species. Honeydew plays a significant role in this species' diet. In exchange for collecting and eating honeydew from the insects that it tends, it protects the insects from other predators and parasitoids. It also destroys insects that have been parasitized before the parasitoid completes development. The
Ant crickets are one notable species that live in nests. Ants are aggressive toward the crickets and will attack if they realize the crickets are there. However, crickets have learned to imitate the way ants use their antennae to identify other individuals and trick the ants into allowing the crickets to stay. Crickets even participate in trophallaxis with the ants. The ants do not seem to gain any benefits from the crickets' presence, while the crickets get shelter, food, and will even attempt to eat larvae if given access. Other ant species have also been documented living in the nests of . Formica dakotensis has been found living peacefully in the same mounds as in Yellowstone National Park. Leptothorax hirticornis may eat larvae and isolated workers given the opportunity, and Tapinoma sessile often steals honeydew from within the nest, but does not act particularly aggressive to these other ant species. (Conway, 1996a; Henderson and Akre, 1986; Mico, et al., 2000; Risch, et al., 2008)
Uropoda are often found on both workers and sexuals, often in the joints of the legs. The wasp Elasmosoma michaeli is a parasitoid of workers. The wasp lays eggs in the abdomens of worker ants, killing the ants upon hatching. As a significant aphid-tending ant species, can play a role in determining the density of other arthropods and herbivores in their habitat. In some habitats, such as a coastal dune habitat, is a keystone species. It reduces competing herbivores on the aphid-infested plants, while also increasing arthropod density by creating new shelters by rolling leaves on which the aphids live. is also known to collect seeds and bring them back to the nest. It eats the edible part and stores the rest of the seed in chambers of the nest. These chambers can often be a good habitat for the plant to grow and develop, allowing the ant to aid in seed dispersal. (Berg-Binder and Suarez, 2012; Conway, 1996a; Crutsinger and Sanders, 2005; Shaw, 2007)plays a variety of other roles in the ecosystem. It is prey to a variety of insects and bird species. It also feeds on a large number of other insect species. Ectoparasitic mites of genus
- Ecosystem Impact
- disperses seeds
- creates habitat
- keystone species
- aphids (Aphididae)
- aphids (Pleotrichophorus utensis)
- aphids (Uroleucon escalantii)
- aphids (Lachnus allegheniensis)
- aphids (Aphis)
- aphids (Macrosiphum)
- aphids (Pleotrichophorus)
- modest treehoppers (Publilia modesta)
- jumping plant lice (Psylloidea)
- Amonosterium lichtensioides
- Disholcaspis perniciosa
Economic Importance for Humans: Positive
- Positive Impacts
- controls pest population
Economic Importance for Humans: Negative
There are no known adverse effects ofon humans.
has no special conservation status.
Angela Miner (author), Animal Diversity Web Staff, Leila Siciliano Martina (editor), Animal Diversity Web Staff.
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
- bilateral symmetry
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
flesh of dead animals.
uses smells or other chemicals to communicate
used loosely to describe any group of organisms living together or in close proximity to each other - for example nesting shorebirds that live in large colonies. More specifically refers to a group of organisms in which members act as specialized subunits (a continuous, modular society) - as in clonal organisms.
- desert or dunes
in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.
particles of organic material from dead and decomposing organisms. Detritus is the result of the activity of decomposers (organisms that decompose organic material).
- active during the day, 2. lasting for one day.
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
the condition in which individuals in a group display each of the following three traits: cooperative care of young; some individuals in the group give up reproduction and specialize in care of young; overlap of at least two generations of life stages capable of contributing to colony labor
union of egg and spermatozoan
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.
the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.
- internal fertilization
fertilization takes place within the female's body
- keystone species
a species whose presence or absence strongly affects populations of other species in that area such that the extirpation of the keystone species in an area will result in the ultimate extirpation of many more species in that area (Example: sea otter).
A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.
having the capacity to move from one place to another.
- native range
the area in which the animal is naturally found, the region in which it is endemic.
an animal that mainly eats all kinds of things, including plants and animals
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
chemicals released into air or water that are detected by and responded to by other animals of the same species
"many forms." A species is polymorphic if its individuals can be divided into two or more easily recognized groups, based on structure, color, or other similar characteristics. The term only applies when the distinct groups can be found in the same area; graded or clinal variation throughout the range of a species (e.g. a north-to-south decrease in size) is not polymorphism. Polymorphic characteristics may be inherited because the differences have a genetic basis, or they may be the result of environmental influences. We do not consider sexual differences (i.e. sexual dimorphism), seasonal changes (e.g. change in fur color), or age-related changes to be polymorphic. Polymorphism in a local population can be an adaptation to prevent density-dependent predation, where predators preferentially prey on the most common morph.
- seasonal breeding
breeding is confined to a particular season
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
uses touch to communicate
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
Living on the ground.
- tropical savanna and grassland
A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.
A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.
- temperate grassland
A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.
uses sight to communicate
Beattie, A., D. Culver. 1977. Effects of the Mound Nests of the Ant, American Midland Naturalist, 97/2: 390-399., on the Surrounding Vegetation.
Berg-Binder, M., A. Suarez. 2012. Testing the directed dispersal hypothesis: are native ant mounds (Formica sp.) favorable microhabitats for an invasive plant?. Oecologia, 169/2: 763-772.
Billick, I., C. Carter. 2007. Testing the importance of the distribution of worker sizes to colony performance in the ant species Insectes Sociaux, 54/2: 113-117.Forel.
Conway, J. 1996. A field study of the nesting ecology of the thatching ant, Great Basin Naturalist, 56/4: 326-332.Forel, at high altitude in Colorado.
Conway, J. 1996. Nuptial, pre-, and postnuptial activity of the thatching ant, Great Basin Naturalist, 56/1: 54-58.Forel, in Colorado.
Crutsinger, G., N. Sanders. 2005. Aphid-Tending Ants Affect Secondary Users in Leaf Shelters and Rates of Herbivory on Salix hookeriana in a Coastal Dune Habitat. American Midland Naturalist, 154/2: 296-304.
Erickson, D., E. Wood, K. Oliver, I. Billick, P. Abbot. 2012. The Effect of Ants on the Population Dynamics of a Protective Symbiont of Aphids, Hamiltonella defensa. Annals of the Entomological Society of America, 105/3: 447-453.
Fraser, A., A. Axen, N. Pierce. 2001. Assessing the quality of different ant species as partners of a myrmecophilous butterfly. Oecologia, 129/3: 452-460.
Grinath, J., B. Inouye, N. Underwood, I. Billick. 2012. The indirect consequences of a mutualism: comparing positive and negative components of the net interaction between honeydew-tending ants and host plants. Journal of Animal Ecology, 81/2: 494-502.
Heikkinen, M. 1999. Negative effects of the western thatching ant (Araneae) inhabiting big sagebrush (Artemisia tridentata). Great Basin Naturalist, 59/4: 380-383.) on spiders (
Herbers, J. 1979. Caste-biased Polyethism in a Mound-building Ant Species. American Midland Naturalist, 101/1: 69-75.
McIver, J., T. Steen. 1994. Use of a secondary nests in Great Basin desert thatch ants (Great Basin Naturalist, 54/4: 359-365.Forel).
Mico, E., A. Smith, M. Moron. 2000. New Larval Descriptions for Two Species of Euphoria Burmeister (Coleoptera: Scarabaeidae: Cetoniinae: Cetoniini: Euphoriina) with a Key to the Known Larvae and a Review of the Larval Biology. Annals of the Entomological Society of America, 93/4: 795-801.
Risch, A., M. Jurgensen, A. Storer, M. Hyselop, M. Schutz. 2008. Abundance and distribution of organic mound-building ants of the Formica rufa group in Yellowstone National Park. Journal of Applied Entomology, 132/4: 326-336.
Seibert, T. 1993. A nectar-secreting gall wasp and ant mutualism - selection and counter-selection shaping gall wasp phenology, fecundity, and persistence. Ecological Entomology, 18/3: 247-253.
Seibert, T. 1992. Mutualistic interactions of the aphid Lachnus allegheniensis (Homoptera, Aphididae) and its tending ant (Hymenoptera, Formicidae). Annals of the Entomological Society of America, 85/2: 173-178.
Shaw, S. 2007. A new species of Elasmosoma ruthe (Hymenoptera : Braconidae : Neoneurtnae) from the northwestern United States associated with the western thatching ants, Forel and Formica obscuriventris clivia Creighton (Hymenoptera : Formicidae). Proceedings on the Entomological Society of Washington, 109/1: 1-8.
Talbot, M. 1972. Flights and Swarms of the Ant Journal of the Kansas Entomological Society, 45/2: 254-258.Forel.
Tilman, D. 1978. Cherries, Ants and Tent Caterpillars: Timing of Nectar Production in Relation to Susceptibility of Caterpillars to Ant Predation. Ecology, 59/4: 686-692.
Weber, N. 1935. The Biology of the Thatching Ant, Formica rufa obscuripes Forel, in North Dakota. Ecological Monographs, 5/2: 165-205.