Mycetophylax olitor

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Mycetophylax olitor
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Mycetophylax
Species: M. olitor
Binomial name
Mycetophylax olitor
(Forel, 1893)

Cyphomyrmex olitor casent0281769 p 1 high.jpg

Cyphomyrmex olitor casent0281769 d 1 high.jpg

Specimen Labels

Synonyms

Kempf (1964) reported "There are no pertinent data, except for the fact that all collections of Mycetophylax olitor and Cyphomyrmex quebradae, its synonym, were made in mesophilous subtropical woods, in rather moist surroundings.

Identification

See the description below.

Distribution

The species, as presently defined, is known to occur in northwestern Argentine (Tucumán) and southeastern Brazil, from Rio Grande do Sul to Rio de Janeiro States.

Latitudinal Distribution Pattern

Latitudinal Range: 25.68015° to -28.4°.

     
North
Temperate
North
Subtropical
Tropical South
Subtropical
South
Temperate

Distribution based on Regional Taxon Lists

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

Distribution based on AntMaps

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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.
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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.
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Biology

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. ‎

Castes

Nomenclature

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

  • olitor. Cyphomyrmex olitor Forel, 1893e: 605 (w.q.) BRAZIL.
    • Wheeler, G.C. 1949: 670 (l.).
    • Combination in Atta (Cyphomyrmex), with unjustified emendation of spelling to olitrix: Forel, 1911c: 295.
    • Combination in Cyphomyrmex: Luederwaldt, 1918: 39.
    • Combination in Mycetophylax: Sosa-Calvo et al., 2017: 9.
    • Senior synonym of quebradae: Kempf, 1964d: 30.
  • quebradae. Cyphomyrmex quebradae Kusnezov, 1949d: 445, figs. 6-8, 11 (w.q.m.) ARGENTINA.
    • Junior synonym of olitor: Kempf, 1964d: 30.

Description

Kempf (1964) - The numerous specimens from southern Brazil, unfortunately all strays from berlesate collections, show an unusual range of variation. Only the lone workers from Petrópolis and Marambaia, Rio de Janeiro State, agree almost completely with the types. All others present a variable amount of discordant features. I have tried to separate the principal variants with the intention of discovering the existence of two or more so-called sibling species. But so far, all my attempts have been unsuccessful. Therefore I limit myself to an account of the chief variable characters for the worker caste.

1. Size: The types are near the lower end of the range. The largest specimen had the following measurements: Total length 3.5 mm; head length 0.85 mm; head width 0.77 mm; thorax length 1.09 mm; hind femora length 0.83 mm.

2. Head: Mandibular teeth 7-10, frontal lobes more often evenly rounded rather than rectangular; frontal carinae subparallel in the largest specimens; occipital lobes sometimes less distinctly set off in full face view.

3. Thorax: midpronotal tubercles strong to almost obsolete; lateral pronotal and both pairs of mesonotal tubercles usually lower than in types; mesoepinotal constriction variable; epinotal teeth either vestigial or well developed, with all kinds of intermediate conditions; hind femora moderately to conspicuously dilated and ventrally angulate at basal third, postero-ventral border always carinate, sometimes with a prominent foliaceous flange at angle.

4. Pedicel and gaster: lateral lobes of petiole, in ventral view, weakly to moderately longitudinally furrowed, the lateral border, especially on the posterior half carinate; in profile, the petiole is either completely depressed or shows an ascending anterior face distinct from a horizontal dorsal face (as in daguerrei), especially in larger specimens; in larger specimens the postero-dorsal transverse laminule forms sometimes a prominent semicircular apron; shape of postpetiole extremely variable in dorsal view, with all possible intergrades between extremes; lateral borders of tergum of postpetiole either completely appressed to sternum as in olitor types, or salient with more or less developed foliaceous margin; lateral borders of tergum I of gaster varying between sharply and indistinctly marginate.

As said before, I am reluctant to lump this variable array of forms under one species, but I cannot see another solution under the present circumstances. Later on, when good series from many colonies will be available, one might be tempted again to try for more satisfactory results.

Worker

Kempf (1964) - (lectotype) Total length 2.6 mm; head length 0.64 mm; head width 0.56 mm; thorax length 0.78 mm; hind femur length 0.59 mm. Yellowish brown, vertex of head more reddish brown. Integument opaque, densely and minutely granulate. Dorsum of head between frontal carinae and tergum I of gaster with small piligerous tubercles.

Head (fig 7). Mandibles finely reticulate-punctate and somewhat longitudinally rugulose; chewing border with 7-8 teeth, gradually diminishing in size towards base. Anterior clypeal border scarcely notched in the middle, laterally with a small tooth on each side. Frontal area distinct and impressed. Frontal lobes oblique, rectangular, moderately expanded laterad, not reaching in full-face view the preocular carinae, covering only in part the antennal scrobe; lateral borders somewhat diverging and sinuous, posterior prolongation of frontal carinae nearly straight and gently diverging caudad. Occipital corners slightly produced. Occiput broadly and shallowly excised, with another somewhat deeper excision in the middle between the short, but prominent carinae of vertex. Supraocular tumulus feeble and indistinct. Postero-inferior corner of head without a foliaceous carinule. Scapes in repose attaining but not surpassing the occipital corner. Funicular segments II-VII scarcely longer than broad.

Thorax (fig 19). The single midpronotal tubercle low, often indistinct: lateral teeth much more prominent; antero-inferior corner of pronotum forming a slightly protruding yet subrectangular tooth. Mesonotum flat to slightly excavate, with the costumary two pairs of tubercles, one tubercle to each corner; anterior tubercles in profile broadly rounded, tumuliform; posterior tubercles subconical with broadly rounded apex. Mesoepinotal constriction pronounced. Basal face of epinotum nearly as long as declivous face, with a pair of blunt tubercles at anterior border, another faintly marked pair posteriorly, marking the limit of the declivous face. Femora very lightly crested beneath. Hind femora only gently dilated at basal third, the postero-ventral crest not forming at this place a prominent foliaceous flange.

Pedicel (19, 33). Note the narrow postero-median laminule flanked by very faint longitudinal carinules. Lateral lobes solid, only shallowly excavated beneath. Postpetiole cupuliform, dorsally broadly impressed, the impression flanked by a low and blunt ridge which terminates posteriorly in a low, scarcely raised tubercle. Lateral lobes completely appressed to sternum, not excavated beneath nor foliaceous. Tergum I of gaster with a faint longitudinal furrow on anterior half, the lateral borders distinctly marginate, especially on anterior half.

Hairs on thorax and pedicel minute appressed, indistinct; head, gaster and appendages with small recurved and decumbent hairs.

Queen

Kempf (1964) - (paratypes) Total length 3.3-3.4 mm; head length 0.75-0.77 mm; head width 0.67-0.68 mm; thorax length 0.96-0.98 mm; hind femur length 0.72-0.75 mm. Ferruginous; decidedly darker than the workers of the type series. Head as in worker, including shape of frontal carinae, slightly protruding occipital lobes. Ocelly very small. Mandibles with 7-8 teeth. Pronotum laterally immarginate, with a strong conical tooth on each side. Midpronotal tooth absent. Antero-inferior corner of latero-tergite of pronotum with a prominent tooth. Scutum flat troughout; anteriorly with a pair of faint tumuli just inside the anterior extremity of the arms of the vestigial and scarcely impressed Mayrian furrows, Scutellum posteriorly distinctly bidentate, a semicircular excision separating the two teeth. Basal face of epinotum continuous with declivous face, i. e. dropping down steeply to petiolar insertion just behind the meta-epinotal suture. Epinotal teeth small, much as in nemei. All femora with the postero-ventral border marginate and finely carinulate; hind femora very gently thickened at basal third, without a projecting foliaceous flange. Postpetiole broader and stouter than in worker, with a deep and large dorsal impression, flanked by a pair of longitudinal and slightly carinulate welts; postero-lateral impressions also present; lateral lobes of tergum completely appressed to sternum. Tergum I of gaster covered with abundant piligerous tubercles, its anterior half carinate laterally, mesially with a shallow and rather indistinct longitudinal furrow. Wings unknown. Pilosity as in worker.

Male

Kempf (1964) - described by Kusnezov (1949) as the synonomized Cyphomyrmex quebradae.

Type Material

Kempf (1964) - 3 Workers (lectotype and paratypes) and 2 females (paratypes), collected by Dr. A. Moeller near Blumenau, Santa Catarina State, Brazil, received on loan from the Forel collection (MHNG). 6 workers and 1 female, syntypes of quebradae Kusnezov, received as a gift from Miguel Lillo Institute (WWK).

References

  • Forel, A. 1893h. Note sur les Attini. Ann. Soc. Entomol. Belg. 37: 586-607 (page 605, worker, queen described)
  • Forel, A. 1911e. Ameisen des Herrn Prof. v. Ihering aus Brasilien (Sao Paulo usw.) nebst einigen anderen aus Südamerika und Afrika (Hym.). Dtsch. Entomol. Z. 1911: 285-312 (page 295, Combination in Atta (Cyphomyrmex), with unjustified emendation of spelling to olitrix)
  • 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 30, Senior synonym of quebradae)
  • Kusnezov, N. 1949. El género Cyphomyrmex (Hymenoptera, Formicidae) en la Argentina. Acta Zoologica Lilloana 8:427-456.
  • Luederwaldt, H. 1918. Notas myrmecologicas. Rev. Mus. Paul. 10: 29-64 (page 39, Combination in Cyphomyrmex)
  • 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).
  • Wheeler, G. C. 1949 [1948]. The larvae of the fungus-growing ants. Am. Midl. Nat. 40: 664-689 (page 670, larva described)

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).
  • Wheeler G. C. 1949. The larvae of the fungus-growing ants. Am. Midl. Nat. 40: 664-689.
  • Wild, A. L. "A catalogue of the ants of Paraguay (Hymenoptera: Formicidae)." Zootaxa 1622 (2007): 1-55.