Mycetophylax occultus

Mycetophylax occultus
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Myrmicinae
Tribe:	Attini
Genus:	Mycetophylax
Species:	M. occultus
Binomial name
	Mycetophylax occultus; (Kempf, 1964)

This species is only known from reproductives.

Identification

See the description section below.

Distribution

Distribution based on Regional Taxon Lists

Neotropical Region: Brazil (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.

occultus. Cyphomyrmex occultus Kempf, 1964d: 41, figs. 37-39 (q.m.) BRAZIL.
- Combination in Mycetophylax: Sosa-Calvo et al., 2017: 9.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Description

On account of the reticulate-punctate and somewhat shining antennal scrobe, occultus belongs to the olitor-subgroup. The female differs from Mycetophylax olitor and allies in the large eyes; in the relatively large and prominent ocelli; in the long antennal scape that noticeably surpasses the distinctly drawn out occipital lobes; in the markedly angular anterior corner of pronotum, which is also laterally marginate, its laterotergite bearing a large subcircular impression; in the slender, ventrally ecarinate femora, the hind femora not being ventrally angular nor visibly incrassate at basal third; in the elongate petiolar node that bears dorsally a pair of prominent teeth.

Worker

Queen

(holotype) Total length 4.0 mm; head length 0.88 mm; head width 0.72 mm; scape length 0.77 mm; eye length 0.25 mm; thorax length 1.28 mm; hind femur length 1.06 mm. Ferruginous; funiculi and legs more yellowish-brown; ocellar triangle fuscous. Integument opaque, granular; sides of head and gaster finely and sharply reticulate-punctate; antennal scrobe more coarsely reticulate-punctate and somewhat shining; dorsum of head between frontal carinae and tergum I of gaster with minute piliferous tubercles.

Head (fig 37, 38). Mandibles finely reticulate-punctate and vestigially striolate; chewing border with 7-8 teeth. Clypeus with the anterior border strongly convex in middle, not notched; a small tooth on each side at origin of the moderately expanded, somewhat unevenly and broadly rounded frontal lobes. Frontal area impressed, reticulate-punctate. Posterior portion of frontal carinae gently diverging and straight. Occipital lobes prominent both in dorsal and lateral view. Preocular carina well developed, reaching the occipital lobe. Supraocular tubercle distinct. Eyes comparatively huge, their greatest diameter nearly one third of head length. Ocelli also large, the posterior ones situated on lateral face of prominent tumuli. Inferior border of head marginate. Scape in repose projecting beyond occipital angle by a distance that exceeds its maximum width. Funicular segments II-VII slightly longer than broad.

Thorax (fig 37). Pronotum: midpronotal tubercle absent, lateral borders marginate, anterior corner bluntly tubercular, posterior corner with a prominent stout tooth; latero-tergite with a large subcircular impression; antero-inferior corner subdentate. Mesonotum: Scutum dorsally flat, Mayrian furrows very shallow to vestigial in the rear. Scutellum posteriorly bluntly and weakly bidentate. Basal face of epinotum oblique, laterally carinate; epinotal teeth subtriangular, compressed. Legs long: femora slender, not noticeably incrassate towards basal third, ventral borders carinate, lacking a prominent flange on hind femora.

Pedicel (fig 37, 39). Petiole in dorsal view elongate, its anterior corners marked and bluntly dentate; its dorsum posteriorly with a pair of prominent teeth; posterior border without a prominent, thin, transverse laminule. Postpetiole nearly twice as broad as long, subtrapezoidal, longitudinally traversed by two pairs of carinae, the mesial pair sharp, the lateral pair blunt; dorsum deeply impressed between mesial carinae, more shallowly between mesial and lateral carinae. Gaster antero-laterally marginate; tergum I with a median longitudinal furrow, which is rather faint and fades out before reaching the midlength of the segment.

Wings slightly infumated, venation as in the other known species (fig 43).

Body and appendages with very small, strongly curved, subdecumbent hairs.

Male

I have 14 specimens of this caste, but forego a detailed diagnosis at this time. They are at once recognized by their huge eyes and elongate petiole, similar to that of the female.

Type Material

5 females (holotype and paratypes) and 8 males, taken by Fritz Plaumann at Nova Teutônia, Santa Catarina State, Brazil, in October 1960 (WWK n. 3918); 6 females (paratypes) and 6 males taken by Karol Lenko at Barueri, São Paulo State, on October 17 and November 14, 1958 (n. 662 and 698), more specimens of the same series in DZSP.

References

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 41, figs. 37-39 queen, male 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. 1978. A preliminary zoogeographical analysis of a regional ant fauna in Latin America. 114. Studia Entomologica 20: 43-62.
Ulyssea M.A., C. E. Cereto, F. B. Rosumek, R. R. Silva, and B. C. Lopes. 2011. Updated list of ant species (Hymenoptera, Formicidae) recorded in Santa Catarina State, southern Brazil, with a discussion of research advances and priorities. Revista Brasileira de Entomologia 55(4): 603-611.