Sericomyrmex saramama

Sericomyrmex saramama
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Myrmicinae
Tribe:	Attini
Genus:	Sericomyrmex
Species:	S. saramama
Binomial name
Sericomyrmex saramama Ješovnik & Schultz, 2017

The fungal cultivar associated with this species, at least where it was collected in Peru, is a member of the diverse clade of generalized higher-attine fungi grown by species of Sericomyrmex and Trachymyrmex, but it occupies a long, separate branch from all other higher-attine cultivars (Ješovnik et al. 2017b). S. saramama grows this cultivar species even when other cultivars are readily available; it was collected at the same locality in which two Sericomyrmex mayri and two S. parvulus nests were growing a different fungal species, the “amabilis-mayri” species, that is widely cultivated by Sericomyrmex species across the range of the genus.

Identification

Ješovnik & Schultz (2017) - Small species; mandibles dorsally smooth and glossy; frontal lobe triangular, weakly directed anterad, with short posterior margin; frontal carina complete; eye without white layer; mesosomal tubercles low; gaster with lateral carinae moderately developed, dorsal carinae weakly to strongly developed.

Sericomyrmex saramama can be separated from the similar Sericomyrmex parvulus and Sericomyrmex opacus by its larger size, complete frontal carinae, larger eyes that lack a white layer, and frontal lobe shape and size. The queen of S. saramama is similar in size to S. opacus and S. parvulus queens, but it can be separated from them by its striate mandibles (smooth in parvulus and opacus).

Within-species variation includes the dorsal gastral carinae, which are robust in the Peru population but hardly visible in the Ecuador population. Sericomyrmex saramama is the sister species of a clade containing Sericomyrmex maravalhas + Sericomyrmex scrobifer, Brazilian cerrado species that are also rarely collected. Together, S. saramama + (S. maravalhas + S. scrobifer) form a clade that is the sister to all remaining Sericomyrmex species. Morphologically, S. saramama resembles opacus more than its sister species.

Keys including this Species

• Key to Sericomyrmex

Distribution

Ješovnik & Schultz (2017) - Colombia, Ecuador, Peru. Sericomyrmex saramama occurs in forested habitats in Peru, Colombia, and Ecuador, but has never been collected in Amazonian Brazil. No other Sericomyrmex species has a similar distribution, although the known distribution could easily be an artifact of undersampling.

Latitudinal Distribution Pattern

Latitudinal Range: -0.6382° to -12.819°.

North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

• Source: AntMaps

Distribution based on Regional Taxon Lists

Neotropical Region: Brazil, Ecuador, Peru (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

Expand 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. some Apterostigma Cyatta (1 species) some Cyphomyrmex Kalathomyrmex (1 species) Mycocepurus (6 species) Myrmicocrypta (31 species) Mycetarotes (4 species) Mycetosoritis (2 species) Mycetophylax (21 species) Paramycetophylax (1 species) Xerolitor (1 species) 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. Mycetomoellerius (33 species) Paratrachymyrmex (9 species) Sericomyrmex (11 species) Trachymyrmex (9 species) 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. Acromyrmex (51 species) Amoimyrmex (3 species) Atta (20 species) 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

Figure 53bdf.

Figure 54.

Jesovnik and Schultz 2017. Figure 53bdf. Queen (USNMENT00924065). Figure 54. S. saramama worker (USNMENT01125262), SEM images. a Head, full-face view b mandibles c metasoma, lateral view d eye.

Figure 55.

Jesovnik and Schultz 2017. Figure 55. S. saramama larva (USNMENT01125266), SEM images. a Lateral view b ventral view c head, frontodorsal view d head, lateral view e mouthparts f anal setae.

Nomenclature

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

• saramama. Sericomyrmex saramama Ješovnik & Schultz, 2017a: 86, figs. 53-55 (w.q.l.) PERU.
  • Type-material: holotype worker, 11 paratype workers, 1 paratype queen.
  • Type-locality: holotype Peru: Madre de Dios, Tambopata Reserve, -12.8187, -69.3636, 224 m., AJ 120729-03, primary forest (A. Ješovnik); paratypes with same data.
  • Type-depositories: MUSM (holotype); BMNH, CASC, MCZC, MHNG, MSNG, MZSP, USNM (paratypes).
  • Status as species: Fernández & Serna, 2019: 874.
  • Distribution: Colombia, Ecuador, Peru.

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

Description

Worker

(holotype): HWe 0.9–1.13 (1) HW 0.9–1.13 (0.98) HW1 0.6–1.05 (0.93) HW2 0.9–1.16 (1.02) HW3 0.53–0.76 (0.65) IFW1 0.58–0.78 (0.65) IFW2 0.22–0.35 (0.31) HL1 0.84–1.1 (0.96) HL2 0.78–0.98 (0.87) SL 0.65–0.8 (0.72) EL 0.11–0.18 (0.16) Om 7–9 (8) WL 1.12–1.4 (1.3) PL 0.22–0.38 (0.28) PPL 0.19–0.3 (0.25) GL 0.78–0.98 (0.86) HFL 0.95–1.2 (1.13) PW 0.54–0.74 (0.65) CI 97–109 (104) FLI 61–82 (65) SI 68–78 (72) OI 12–17 (16) CEI 7–12 (9) [N=25]

Pilosity. Pubescence dense, lighter than integument, appressed to decumbent. Hairs curved, darker in color at base, appressed to suberect, mostly decumbent.

Head. In full-face view slightly broader than long (CI=103 ± 3), posterior corner smoothly rounded to acute, lateral margin of head slightly convex, posterior cephalic emargination distinct (CEI=10 ± 2), gradually impressed. Vertexal impression usually distinct, frontal tumuli faint. Mandible with 7–8 teeth, dorsally smooth and glossy, finely transversely striate only along masticatory margin. Eye medium-sized (OI =15 ± 1), slightly convex, without white layer, 7–9 ommatidia across largest diameter. Frontal lobe moderately wide (FLI=67 ± 3), triangular, weakly directed anterad, posterior margin shorter than medial. Frontal carina not very robust, usually complete, reaching posterior cephalic corner. Antennal scape moderately long (SI=72 ± 3), sometimes almost reaching posterior cephalic corner.

Mesosoma. Mesosomal tubercles low and obtuse. Propodeal carinae low, rarely with posterodorsal denticles.

Metasoma. Petiole with two low, reduced dorsal denticles; node of postpetiole with two faint, short dorsal carinae, both best seen in dorsolateral view. First gastral tergite with lateral carinae relatively weak, dorsal carinae from barely visible to well developed.

Queen

HWe 1.35 HW 1.4 HW1 1.4 HW2 1.5 HW3 0.95 IFW1 0.93 IFW2 0.38 HL1 1.32 HL2 1.16 SL 0.88 EL 0.22 Om 15 EW 0.11 WL 1.92 PL 0.48 PPL 0.36 GL 1.82 HFL 1.48 PW 1.08 CI 102.27 FLI 68.89 SI 64.81 OI 16 [N=1]

Head. Mandible with 8 teeth, dorsally striate, differing from worker. Preocular carina fading posterior to eye. Eye large, slightly convex, 15 ommatidia across largest diameter. Frontal lobe slightly more robust than in worker.

Mesosoma. Scutum in dorsal view with notauli very reduced, median mesoscutal line absent. Parapsidal lines thin, slightly curved. Scutellum in dorsal view narrowing posteriorly, posterior notch shallow. Propodeal denticles blunt and low, directed posterolaterad.

Metasoma. First gastral tergite with lateral carinae weakly to moderately developed, dorsal carinae absent, anteromedian dorsal groove visible.

Larva

Setae on dorsal and lateral body surfaces and supra-antennal setae absent. Four genal setae on each side. Mandibular apical tooth divided. Labial denticles absent. First thoracic segment ventrally with multiple multidentate spinules, arranged in transverse rows. Numbers of ventral setae: six on each thoracic segment, two on the abdomen (not including anal setae). Single pair of papilliform setae anterior to anal opening.

Type Material

Holotype worker: Peru: Madre de Dios, Tambopata Reserve, -12.8187, -69.3636, 224m, A. Ješovnik, AJ120729-03, primary forest, nest on forest trail. (Museo de Historia Natural: 1w, USNMENT00924064). Paratypes: same data as holotype (National Museum of Natural History: 1q, USNMENT00924065; 1w, USNMENT00924070) (Museu de Zoologia da Universidade de Sao Paulo: 1w, USNMENT00924068; 1w, USNMENT00924069) (Museum of Comparative Zoology: 1w, USNMENT00924071; 1w, USNMENT00924080), (California Academy of Sciences: 1w, USNMENT00924072; 1w, USNMENT00924073) (Musee d'Histoire Naturelle Genève, 1w, USNMENT00924074) (The Natural History Museum: 1w, USNMENT00924077) (Museo Civico di Storia Naturale, Genoa: 1w, USNMENT00924078; 1w, USNMENT00924079).

Etymology

This species is named after the Incan goddess of grain, Saramama, because the type locality is in the former Incan Empire (modern-day Peru) and because Sericomyrmex is an ant that practices agriculture. The species name is a noun in apposition.

References

• Ješovnik, A., Schultz, T.R. 2017. Revision of the fungus-farming ant genus Sericomyrmex Mayr (Hymenoptera, Formicidae, Myrmicinae). ZooKeys 670, 1–109 (doi:10.3897/zookeys.670.11839).
• Ješovnik A, Sosa-Calvo J, Lloyd M, Branstetter M, Fernández F, Schultz TR. 2017b. Phylogenomic species delimitation and host-symbiont coevolution in the fungus-farming ant genus Sericomyrmex Mayr (Hymenoptera: Formicidae): Ultraconserved elements (UCEs) resolve a recent radiation. Systematic Entomology. doi:10.1111/syen.12228

References based on Global Ant Biodiversity Informatics

• Jesovnik A., J. Chaul, and T. Schultz. 2018. Natural history and nest architecture of the fungus-farming ant genus Sericomyrmex (Hymenoptera: Formicidae). Myrmecological News 26: 65-80.