Mycetophylax bruchi

Mycetophylax bruchi
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Myrmicinae
Tribe:	Attini
Genus:	Mycetophylax
Species:	M. bruchi
Binomial name
	Mycetophylax bruchi; Santschi, 1917 Specimen Labels

Nothing is known about the biology of this species.

Identification

See the nomenclature section below.

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: -21.2061° to -21.2061°.


North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

Source: AntMaps

Distribution based on Regional Taxon Lists

Neotropical Region: Argentina (type locality).

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.

Biology

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.

some Crematogaster
some Lasius

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.

some Apterostigma

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.

some Cyphomyrmex

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. ‎

Castes

Nomenclature

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

bruchi. Cyphomyrmex bruchi Santschi, 1917f: 282 (w.) ARGENTINA.
- Combination in Mycetophylax: Sosa-Calvo et al., 2017: 9.
- See also: Kempf, 1964d: 34.

Kempf (1964) - Mycetophylax bruchi, although the mandibles bear in the types scarcely distinguishable teeth, except the apical one, belongs doubtless to the strigatus-group, as shown by the arrangement of the frontal carinae and preocular carinae. It is misplaced both in Weber's (1940) and especially in Kusnezov's (1949 and 1957) keys. According to the latter, it would fall into the rimosus-group.

The closest relatives are found in the difficult olitor-subgroup. Following are the most outstanding differences from the better known species of this assembly.

It differs from Mycetophylax lectus Forel in larger size; in the shape of the frontal lobes, which are less expanded laterad and distinctly subcircular in outline; in the indistinct dentition of the mandibles; in the lack of paired carinae on vertex, in the antero-inferior tooth of pronotum which is not greatly produced; in the ill-defined anterior mesonotal tubercles; in the feebly impressed mesoepinotal groove; in the long basal face of epinotum, which is about as long the declivous face; in the extremely broad postpetiole of different shape.

Mycetophylax daguerrei Santschi is even more remote, from which bruchi workers may be distinguished at once by the less produced clypeus, by the better developed frontal lobes, the smoother head sculpture, the lack of vertical carinae, the length of the antennal scapes, which do not surpass in repose the occipital lobe, by the sharply carinate posterior borders of the antennal scrobe, by the absence of a midpronotal tubercle and the weak lateral ones, by the absence of anterior and the ill-developed posterior mesonotal tubercles, by the shallowly impressed mesoepinotal groove, by the ventrally angulate and carinate hind femora, by the extremely transverse postpetiole, by the lack of piligerous tubercles on first gastric tergite.

On account of the broadly transverse postpetiole it resembles somewhat quebradae, which I have synonymized with Mycetophylax olitor. The shape of the head in full-face view (especially the broadly expanded frontal lobes and widely separated frontal carinae, the absence of carinules on vertex, and the vestigially dentate mandibles), the dorsally flattened thorax with obsolete antero-lateral mesonotal tubercles, the broadly expanded petiole, with the lateral lobes deeply excavate from underneath and foliaceous, the absence of piligerous tubercles on gastric tergum I, separate bruchi from the highly variable olitor.

Description

Worker

Kempf (1964) - Total length 3.0 mm; head length 0.72 mm; head width 0.72 mm; maximum diameter of eyes 0.11 mm; scape length 0.56 mm; thorax length 0.93 mm; hind femur length 0.67 mm. Brown; head fuscous reddish brown. Opaque; finely reticulate-punctate; dorsum of head between frontal carinae and less conspicuously dorsum of gaster rather finely and somewhat irregularly reticulate-rugose. Tergum I of gaster without evident small, piligerous tubercles. The whole insect covered with fine, appressed, scattered and glittering short hairs. Tip of gaster (terga and sterna II-IV) with short and erect hairs.

Head (fig 10) as broad as long. Mandibles finely punctate and vestigially striolate; chewing border with more than 7 vestigial to indistinct teeth (sign of wear?); sides sharply carinate at base; apical tooth prominent. Anterior clypeal border shallowly emarginate in middle, laterally with a small tooth. Frontal area distinct. Frontal carinae anteriorly expanded into prominent subcircular lobes, posteriorly greatly removed from each other and slightly diverging and sinuous, confluent with preocular carina on occipital corner. Vertex without paired carinules. Occiput broadly and shallowly excised between prominent occipital corner (fig 53), with another deeper and narrower excision in the middle. Supraocular tumulus very broad, low and blunt. Scapes in repose not surpassing the occipital corners. Funicular segments II-VIII about as broad as long.

Thorax (fig 21). Pronotum with a pair of low and stout lateral tubercles, midpronotal tubercle practically absent; antero-inferior corner angulate and subdentate. Mesonotum without marked anterior tubercles, posterior tubercles indicated by the sharply marginate, in profile weakly raised, posterior corners. Mesoepinotal groove in the middle very shallow, laterally more deeply impressed. Sides of basal face of epinotum bluntly marginate. Epinotal teeth short and pointed. Dorsum of thorax between pronotal tubercles and epinotal spines flattened to slightly excavated on posterior half of basal face of epinotum. Hind femora ventrally dilated at basal third, the posterior border bearing there a prominent foliaceous flange.

Pedicel (fig 21, 32). Petiolar node subtrapezoidal in dorsal aspect, broader in front than in back, anterior corners rounded, posterior border dorsally with a distinct, obliquely raised, short transverse laminule, flanked by a short, longitudinal carinule. Anterior face distinct from dorsum. Postpetiole a little more than twice as broad as long (31:15), with laterally prominent rounded lobes. Tergal portions of both pedicelar segments ventro-laterally excavate with foliaceous margins, that are not appressed on sternites. Postpetiole posteriorly with a median and two lateral impressions. First gastric tergite antero-laterally submarginate.

Figs. 13-24
Figs. 25-36

Type Material

Kempf (1964) - 3 workers, collected by C. Bruch at La Plata, Buenos Aires Province, Argentina, n. 631; 2 specimens, lectotype (Coll. Santschi, NHMB) and paratype (WWK) seen.

References

Cantone S. 2017. Winged Ants, The Male, Dichotomous key to genera of winged male ants in the World, Behavioral ecology of mating flight (self-published).
Hanisch, P.E., Sosa-Calvo, J., Schultz, T.R. 2022. The last piece of the puzzle? Phylogenetic position and natural history of the monotypic fungus-farming ant genus Paramycetophylax (Formicidae: Attini). Insect Systematics and Diversity 6 (1): 11:1-17 (doi:10.1093/isd/ixab029).
Kempf, W. W. 1964d. A revision of the Neotropical fungus-growing ants of the genus Cyphomyrmex Mayr. Part I: Group of strigatus Mayr (Hym., Formicidae). Stud. Entomol. 7: 1-44 (page 34, see also)
Santschi, F. 1917f. Description de quelques nouvelles fourmis de la République Argentine. An. Soc. Cient. Argent. 84: 277-283 (page 282, worker described)
Sosa-Calvo, J., JesÏovnik, A., Vasconcelos, H.L., Bacci, M. Jr., Schultz, T.R. 2017. Rediscovery of the enigmatic fungus-farming ant "Mycetosoritis" asper Mayr (Hymenoptera: Formicidae): Implications for taxonomy, phylogeny, and the evolution of agriculture in ants. PLoS ONE 12: e0176498 (DOI 10.1371/journal.pone.0176498).

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.
Kempf, W.W. 1972. Catalago abreviado das formigas da regiao Neotropical (Hym. Formicidae) Studia Entomologica 15(1-4).
Klingenberg, C. and C.R.F. Brandao. 2005. The type specimens of fungus growing ants, Attini (Hymenoptera, Formicidae, Myrmicinae) deposited in the Museu de Zoologia da Universidade de Sao Paulo, Brazil. Papeis Avulsos de Zoologia 45(4):41-50