Cyphomyrmex

Mayr, 1862

fungus-growing ants

Species Guides

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Cyphomyrmex is a of small, drab-colored fungus-growing ants in the tribe Attini, found primarily in the Neotropics. These ants cultivate fungi in the tribe Leucocoprineae as their primary food source, with most growing fungal nodules rather than full mycelial gardens. Colonies are typically monogynous and small, rarely exceeding 500 . The genus is divided into two : the strigatus complex (South America only) and the rimosus complex (southern North America to South America). Cyphomyrmex represents a basal lineage among attine ants and serves as sister group to Mycetophylax.

Cyphomyrmex by no rights reserved, uploaded by Philipp Hoenle. Used under a CC0 license.Cyphomyrmex flavidus by (c) Jake Nitta, some rights reserved (CC BY), uploaded by Jake Nitta. Used under a CC-BY license.Cyphomyrmex flavidus by (c) Jake Nitta, some rights reserved (CC BY), uploaded by Jake Nitta. Used under a CC-BY license.

Pronunciation

How to pronounce Cyphomyrmex: /ˌsaɪfoʊˈmɜrmɛks/

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Identification

The frontal carinae form a broad, shield-like structure that completely conceals the antennal sockets—this is diagnostic for the . The is widest across the frontal lobes. Most have low, blunt on the mesosoma rather than true spines. Pilosity is typically appressed and -like, though some species have suberect, squamiform hairs. The body is generally dull and lacks obvious . Species in the rimosus complex have an anteriorly open antennal scrobe and five mandibular teeth, while strigatus complex species have a closed antennal scrobe with six or more mandibular teeth. The first gastral lacks tubercles.

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Habitat

Nests occur in diverse substrates including soil, rotting logs, hollow dead twigs, leaf litter, decaying tree limbs, moss mats on tree trunks, and epiphytic pseudobulbs. Some occupy specialized : C. longiscapus constructs exposed, swallow nest-like clay structures hanging from overhangs in moist environments, while C. transversus has been found nesting in dry coconuts. Nest depth varies considerably, with some chambers as shallow as 10–15 cm and others extending to 30 cm or deeper.

Distribution

Native to the New World, ranging from Central and South America (south to Argentina) northward into the southern United States. The rimosus complex extends from Texas and California east to Florida, while the strigatus complex is restricted to South America. Specific documented locations include the Guiana Shield region of Brazil, São Paulo state, Panama, Puerto Rico, and various Mesoamerican localities.

Diet

Exclusively mycophagous; and larvae feed on cultivated fungi in the tribe Leucocoprineae. cultivate fungal gardens using organic substrates including insect , old , and leaf fragments. Younger workers receive sugary substances from older workers via , while older foraging workers consume plant-derived sugars collected during foraging.

Life Cycle

Complete with , larval, pupal, and stages. Larvae pass through multiple instars, becoming progressively larger and more rotund without drastic morphological changes. exhibit age-based : younger workers serve as nurses tending larvae and fungal gardens, while older workers transition to foraging duties. Workers assist larvae with during molting. , larvae, and pupae may be seasonally restricted within colonies.

Behavior

construct fungal gardens through a staged process: cleaning a surface, applying regurgitated crop fluids and anal secretions to organic material, drying the mixture, and repeating until nodules reach approximately 0.8 mm before transplanting to garden areas. Some display behavioral plasticity in nest construction, creating gardens hanging from roots on nest ceilings. When disturbed, workers often become immobile and feign death for extended periods, drawing appendages close to the body. Workers exhibit aggressive defense against , grasping, biting, and killing wasps that emerge in nests. C. longiscapus exhibits a response to Megalomyrmex raiders, abandoning the nest with and fungus rather than fighting.

Ecological Role

As basal fungus-growing ants, they participate in nutrient cycling through decomposition of organic matter used as garden substrate. Their specialized nesting habits create microhabitats that may support associated organisms. The serves as for in the Diapriidae (Acanthopria, Mimopriella), with rates reaching up to 100% of larvae in some colonies. Some are hosts to social parasitic ants, including Megalomyrmex species that exploit their fungal gardens.

Human Relevance

Research on Cyphomyrmex contributes to understanding the evolution of fungus-growing in ants, with chemical profiles and agricultural practices providing comparative data for more derived attine . The conspicuous nest architecture of C. longiscapus makes it a useful study organism for investigating geographic variation in diversity, garden substrate, and in lower attine ants. No significant direct economic impact or pest status is documented.

Similar Taxa

  • MycetophylaxSister to Cyphomyrmex; both represent basal lineages in the Attini, but Mycetophylax differ in nest architecture and geographic distribution.
  • TrachymyrmexMore derived attine with more complex chemical profiles derived from Cyphomyrmex-like ancestral states; Trachymyrmex typically have more conspicuous mesosomal and different fungal practices.
  • MycocepurusAnother basal attine with small colonies and simple nests, but differs in having smooth, shiny body and different fungal garden structure.

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