Mycetophylax lectus

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Mycetophylax lectus
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Mycetophylax
Species: M. lectus
Binomial name
Mycetophylax lectus
(Forel, 1911)

Cyphomyrmex lectus casent0909376 p 1 high.jpg

Cyphomyrmex lectus casent0909376 d 1 high.jpg

Specimen Labels

This species is only known from two collections.


See the description below.


Aside from the type series, this species has also been recorded by Santschi (1925: 164) from Fives Lille, in Santa Fé Province, Argentina. I have not seen these specimens (Kempf 1964).

Latitudinal Distribution Pattern

Latitudinal Range: -19.08333333° to -31.632389°.

Tropical South

Distribution based on Regional Taxon Lists

Neotropical Region: Argentina, Brazil (type locality), Paraguay.

Distribution based on AntMaps


Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.

Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.


Explore-icon.png Explore Fungus Growing 
For additional details see Fungus growing ants.

A handful of ant species (approx. 275 out of the known 15,000 species) have developed the ability to cultivate fungus within their nests. In most species the fungus is used as the sole food source for the larvae and is an important resource for the adults as well. Additionally, in a limited number of cases, the fungus is used to construct part of the nest structure but is not as a food source.

These fungus-feeding species are limited to North and South America, extending from the pine barrens of New Jersey, United States, in the north (Trachymyrmex septentrionalis) to the cold deserts in Argentina in the south (several species of Acromyrmex). Species that use fungi in nest construction are known from Europe and Africa (a few species in the genera Crematogaster, Lasius).

The details of fungal cultivation are rich and complex. First, a wide variety of materials are used as substrate for fungus cultivating. The so-called lower genera include species that prefer dead vegetation, seeds, flowers, fruits, insect corpses, and feces, which are collected in the vicinity of their nests. The higher genera include non leaf-cutting species that collect mostly fallen leaflets, fruit, and flowers, as well as the leafcutters that collect fresh leaves from shrubs and trees. Second, while the majority of fungi that are farmed by fungus-feeding ants belong to the family Lepiotaceae, mostly the genera Leucoagaricus and Leucocoprinus, other fungi are also involved. Some species utilise fungi in the family Tricholomataceae while a few others cultivate yeast. The fungi used by the higher genera no longer produce spores. Their fungi produce nutritious and swollen hyphal tips (gongylidia) that grow in bundles called staphylae, to specifically feed the ants. Finally, colony size varies tremendously among these ants. Lower taxa mostly live in inconspicuous nests with 100–1000 individuals and relatively small fungus gardens. Higher taxa, in contrast, live in colonies made of 5–10 million ants that live and work within hundreds of interconnected fungus-bearing chambers in huge subterranean nests. Some colonies are so large, they can be seen from satellite photos, measuring up to 600 m3.

Based on these habits, and taking phylogenetic information into consideration, these ants can be divided into six biologically distinct agricultural systems (with a list of genera involved in each category):

Nest Construction

A limited number of species that use fungi in the construction of their nests.

Lower Agriculture

Practiced by species in the majority of fungus-feeding genera, including those thought to retain more primitive features, which cultivate a wide range of fungal species in the tribe Leucocoprineae.

Coral Fungus Agriculture

Practiced by species in the Apterostigma pilosum species-group, which cultivate fungi within the Pterulaceae.

Yeast Agriculture

Practiced by species within the Cyphomyrmex rimosus species-group, which cultivate a distinct clade of leucocoprineaceous fungi derived from the lower attine fungi.

Generalized Higher Agriculture

Practiced by species in several genera of non-leaf-cutting "higher attine" ants, which cultivate a distinct clade of leucocoprineaceous fungi separately derived from the lower attine fungi.

Leaf-Cutter Agriculture

A subdivision of higher attine agriculture practiced by species within several ecologically dominant genera, which cultivate a single highly derived species of higher attine fungus.

Note that the farming habits of Mycetagroicus (4 species) are unknown. Also, while species of Pseudoatta (2 species) are closely related to the fungus-feeding genus Acromyrmex, they are social parasites, living in the nests of their hosts and are not actively involved in fungus growing. ‎

Kempf (1964) - According to Luederwaldt (1926: 267) the nest of this species was found in an open field (same habitat as Mycocepurus goeldii). The cavities were subspherical. The fungus garden is sessile.

Ramos-Lacau et al. (2015) studied Mycetophylax lectus in a transitional area (savanna-forest) between Atlantic forest and cerrado (Brazilian savanna) disturbed by an annual fire regime, in Southeast Brazil. Colonies were located in June 2005 after a bushfire. Eight nests were excavated, five in June and three in October. They found:

Colonies were aggregated and located relatively close to each other, with a mean distance between them of 3.38 ± 2.75 m. The external nest structure of the ant consisted of a single circular nest entrance hole with mean diameter of 0.21 ± 0.06 cm but without a well-formed nest mound on the ground surface. The diameter of nest-entrance hole varied significantly between colonies (t test = 8.22; p < 0.001). The internal structure was formed by a single oval chamber connected to the outside via a single gallery. A yeast-like fungi forming a spongy mass was observed and disposed at the bottom of the chamber. No dedicated garbage chamber was observed in all studied colonies.

Gallery length varied from 8.5 to 17 cm with mean length of 11 ± 3 cm. Mean chamber depth varied from 2 to 3.8cm reaching a mean of 3.05 ± 0.6 cm. Chamber volume varied from 8.2 to 54.3 cm³ with average value of 27.5 ± 15.1 cm³.

These measured nest attributes varied significantly between colonies (i.e. gallery length: T test = 9.7 and p < 0.001; chamber depth: T test = 13.4 and p < 0.001; and chamber volume: T test = 4.8 and p = 0.003). Two other species of the Cyphomyrmex genus (i.e. Mycetophylax strigatus and Cyphomyrmex rimosus) were simultaneously observed in the area with similar patterns of external nest architecture of C. lectus. For C. lectus colonies, the mean number of workers was of 70 ± 49.4 individuals per colony. No significant effect of total number of ant individuals (i.e., colony size) on both gallery length (F= 0.059, g.l. = 1; p= 0.83; Fig 1A) and nest chamber volume (F= 0.22, g.l. = 1; p = 0.65; Fig 1B) was observed but the nest chamber depth increased significantly with increasing the number of ants per colony (F= 7.88, g.l. = 1; P = 0.04; Fig 1C). Ant number per colony explained 54% of the observed variation regarding the chamber depth. As observed to all studied nest attributes, the number of ant individuals also varied significantly between colonies (T test = 4.83 and p = 0.003).

Alates (young reproductive females and males), larvae and pupae were found only in one colony (sampled in October). This colony contained eight females, two males, three larvae and nine pupae. None of the eight investigated colonies contained eggs. A single dealate queen was observed in each eight studied colonies strongly suggesting that this species is monogynous.


Queen and male are unknown.


The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

  • lectus. Atta (Cyphomyrmex) olitrix subsp. lecta Forel, 1911c: 295 (w.) BRAZIL.
    • Combination in Cyphomyrmex: Luederwaldt, 1918: 39.
    • Combination in Mycetophylax: Sosa-Calvo et al., 2017: 9.
    • Raised to species: Kempf, 1964d: 36.


Kempf (1964) - The broadly expanded frontal carinae, the foliaceous carina on postero-inferior corner of head, the huge inferior pronotal spine, the unarmed epinotum, vouch for specific distinction from Mycetophylax olitor. The species seems more closely related with Mycetophylax nemei and perhaps Mycetophylax vallensis.


Kempf 1964 Cyphomyrmex a.jpg

Kempf (1964) - (lectotype and paratypes). - Total length 2.7-2.8 mm; head length 0.64-0.67 mm; head width 0.59-0.61 mm; thorax length 0.80-0.83 mm; hind femur length 0.59-0.61 mm. Yellowish brown; front of head ferruginous; legs rather pale.

Head (fig 12). Mandibles finely reticulate-punctate and vestigially striolate; chewing border with 7 teeth; apical tooth prominent. Anterior clypeal border slightly notched in the middle, laterally with a small tooth. Frontal area more or less distinct and impressed. Frontal lobes greatly expanded laterad, covering in full-face view part of the eyes, anteriorly rounded, then diverging caudad and somewhat sinuous, rounded behind before the gentle constriction; frontal carinae prolonged caudad, slightly diverging, joining the narrowly crested preocular carina to close the antennal scrobe at the scarcely drawn-out occipital corner. Occiput broadly but gently emarginate, with another median and deeper emargination between the short and inconspicuous carinae of the vertex. Supraocular tumulus feeble and indistinct. Inferior border of cheeks immarginate, except for a short and low foliaceous carina in front of the inferior occipital corner. Scapes in repose not surpassing the occipital corner. Funicular segments II-VIII not longer than broad.

Thorax (fig 14). Midpronotal tooth feeble and indistinct, lateral teeth low and subconical, antero-inferior corner with a very long tooth pointing foreward. Mesonotum flat to slightly excavate, flanked by the anterior and posterior pair of very low tubercles, which clearly separate the dorsum from the sides. Mesoepinotal suture distinct, but only gently impressed. Basal face of epinotum much shorter than the laterally immarginate declivous face, posteriorly unarmed. Inferior borders of femora faintly crested; hind femora gradually increasing in depth toward basal third, forming ventrally an angle, the postero-inferior border being armed at this place with a prominent foliaceous flange.

Pedicel (fig 14). Note the narrow postero-median laminule flanked by short longitudinal carinules. Postpetiole cupuliform, dorsally flattened; lateral lobes with foliaceous margin, not appressed. Tergum I of gaster with marginate anterior border, laterally immarginate, mesially not impressed.

Integument densely granulate, opaque, with sparser small setigerous pits. Hairs minute, completely appressed. Gular face of head and sternum I of gaster with curved subdecumbent hairs.

Type Material

Kempf (1964) - 14 workers taken by H. Luederwaldt in the borough of lpiranga in São Paulo City, in 1909 (MHNG, DZSP, WWK).


References based on Global Ant Biodiversity Informatics

  • Kempf W. W. 1964. A revision of the Neotropical fungus-growing ants of the genus Cyphomyrmex Mayr. Part I: Group of strigatus Mayr (Hym., Formicidae). Studia Entomologica 7: 1-44.
  • Silvestre R., M. F. Demetrio, and J. H. C. Delabie. 2012. Community Structure of Leaf-Litter Ants in a Neotropical Dry Forest: A Biogeographic Approach to Explain Betadiversity. Psyche doi:10.1155/2012/306925
  • Soares S. A., W. F. Antoniali Junior, and S. E. Lima-Junior. 2010. Diversidade de formigas epigéicas (Hymenoptera, Formicidae) em dois ambientes no Centro-Oeste do Brasil. Revista Brasileira de Entomologia 54(1): 76–81.
  • Vittar, F. 2008. Hormigas (Hymenoptera: Formicidae) de la Mesopotamia Argentina. INSUGEO Miscelania 17(2):447-466
  • Wild, A. L. "A catalogue of the ants of Paraguay (Hymenoptera: Formicidae)." Zootaxa 1622 (2007): 1-55.