Sericomyrmex scrobifer

Quick Summary

• Difficulty: Hard
• Origin & Habitat: Brazil and Paraguay, primarily in cerrado vegetation (campo cerrado, cerrado sensu stricto, cerradão) at elevations of 240-910 m (mean 666 m) ^[1]. A single record also exists from Colombia (Amazon region) ^[4]. The species is a cerrado specialist, preferring forested areas over open grassland ^[1].
• Colony Type: Colonies typically contain 1-2 queens, making them facultatively polygyne (able to have one or more queens) ^[1]. This is unusual among Attini, which are often strictly monogyne.
• Size & Growth:
  • Queen: Not documented
  • Worker: Body length not reported, only head width (HWe 0.83-1.12 mm) and mesosoma length (WL 1.12-1.40 mm) recorded in literature ^[2]
  • Colony: Unknown, no direct colony size estimates available, nest-mound volume correlates with colony size in related species ^[1]
  • Growth: Unknown, not studied
  • Development: Unknown, not documented for this species (Based on related fungus-farming ants, development likely takes several months under warm, stable conditions, but this is unconfirmed.)
• Antkeeping:
  • Temperature: Based on cerrado habitat, aim for 24-28°C (warm and stable) ^[1]. The fungus garden is sensitive to temperature swings.
  • Humidity: Keep the substrate consistently moist but not waterlogged, especially the fungus garden. Provide good drainage and a humidity gradient (e.g., moisten one side of the nest). In their natural habitat, humidity varies between wet and dry seasons ^[1].
  • Diapause: Unknown, cerrado winters are mild, so they may only slow activity rather than undergo true diapause. No studies confirm this.
  • Nesting: Deep soil nests with chambers up to 79 cm deep and 1-7 chambers ^[1]. In captivity, use a deep soil-based or plaster formicarium that allows chamber construction. Provide at least 30 cm of substrate depth. A large outworld is needed because foragers travel far ^[1].
• Behavior: Fungus-farming ants that are not particularly aggressive but will defend their garden. Foragers travel up to 7.2 m from the nest to collect plant material ^[1]. Workers are small (~4-5 mm inferred), so use fine mesh (0.5 mm or smaller) to prevent escape. They are ground-nesting and prefer to forage in the soil layer.
• Common Issues: Fungus garden collapse is the primary risk, these ants depend entirely on their fungal symbiont, which requires consistent moisture, warmth, and ventilation to survive, Improper nutrition, they cannot survive on typical ant foods (sugar, insects) alone, they need a living fungus culture that must be maintained, Overwatering or drying out, both kill the fungus, which kills the colony, Limited availability of proper substrate and starter fungus culture for this species, most keepers cannot obtain it, Small, slow-growing colonies, losses have a bigger impact because colonies cannot recover quickly

Fungus Farming, The Key to Their Care

Like all Attini, Sericomyrmex scrobifer cultivates a fungus as its primary food source ^[3]. The ants collect plant material (leaf fragments, flower petals, etc.) and feed it to the fungus. In return, the fungus produces gongylidia, specialized nutrient-filled structures that the ants harvest and eat ^[5]. This symbiosis is so tight that the ants cannot survive without the fungus.

Keeping this species means keeping the fungus alive. The fungus requires steady warmth (24-28°C), consistently moist (but not waterlogged) conditions, and good ventilation to prevent mold. Any disturbance to the fungus garden, temperature shock, drying out, or flooding, can quickly kill the colony. This is the central challenge of keeping Sericomyrmex scrobifer and is why it is not a beginner species.

Nest Preferences and Housing

In the wild, nests are underground with chambers reaching 79 cm deep ^[1]. Historical records show 1-7 chambers per colony ^[1]. The ants prefer forested cerrado (cerradão) over open areas ^[1].

For captive housing, you need a deep, soil-based setup that allows the ants to dig and build chambers. A naturalistic formicarium with compacted soil (at least 30 cm deep) works well. You can also use a large plaster nest with deep cavities. Avoid shallow setups, these ants need vertical space to replicate their natural nest architecture and to accommodate the fungus garden alongside brood chambers.

The outworld should be spacious (at least 30×20 cm) because foragers travel up to 7.2 m from the nest in the wild ^[1]. Provide leaf litter or other substrate that mimics the cerrado forest floor.

Temperature and Environmental Conditions

S. scrobifer is a cerrado specialist, so it is adapted to warm conditions with a distinct wet-dry season cycle ^[1]. Aim for 24-28°C year-round. Avoid sudden temperature changes.

Humidity is critical, not directly for the ants, but for their fungus. The fungus needs constant moisture. Keep the substrate consistently damp but not wet. Water when the top layer begins to dry, but never let it dry out completely. Provide good ventilation to prevent mold while keeping humidity high. A gradient (wetter in one area, drier in another) can help the colony choose the optimal spot for the fungus.

Feeding and Nutrition

This is the most critical aspect of keeping S. scrobifer. Unlike typical ants, they cannot eat standard ant foods (sugar water, honeydew, insects). They depend entirely on their cultivated fungus ^[3][5]. The ants gather plant material (leaves, flower petals, dead plant matter) and feed it to the fungus. In turn, they harvest gongylidia, protein- and sugar-rich structures produced by the fungus.

To keep a colony, you must maintain a viable fungus culture. This requires a continuous supply of fresh plant material. Suitable options include young leaves of bramble, rose, or oak, as well as non-toxic flower petals. Avoid leaves with high tannin or pesticide residue. Since specific dietary needs for Sericomyrmex fungus are not well-studied, experimentation with different plant matter may be needed. The fungus is sensitive to improper food, wilting leaves or unsuitable species can cause it to die.

Behavior and Colony Dynamics

Wild colonies have 1-2 queens ^[1]. This suggests the species is facultatively polygyne, established colonies may have one or multiple queens. It is unclear whether new queens found together (pleometrosis) or join existing colonies later.

Foraging is an individual activity. Workers travel up to 7.2 m from the nest to collect plant material for the fungus ^[1]. They are not aggressive but will sting if the nest is disturbed. As a myrmicine ant, S. scrobifer has a functional sting, though it is not medically significant.

The species is rarely collected, likely due to low population densities ^[6]. This, combined with its specialized lifestyle, makes colonies hard to obtain and establish in captivity.

Distribution and Habitat

S. scrobifer is known from Brazil and Paraguay ^[1][2]. A single record also exists from the Colombian Amazon, possibly extending the range ^[4]. It is a cerrado specialist, found almost exclusively in Brazilian savanna habitats (campo cerrado, cerrado sensu stricto, cerradão) ^[1]. Within cerrado, it prefers forested areas over open grasslands ^[1].

Elevation records range from 240 to 910 m above sea level (mean 666 m) ^[1]. The ancestral range of the scrobifer clade (S. scrobifer and its sister S. maravalhas) is estimated as the Chaco-Brazilian region with 88.5% support ^[6]. This indicates a long evolutionary history in the savannas of central South America.

Frequently Asked Questions

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References