Pheidole calimana

Pheidole calimana

Pheidole calimana is a tiny Neotropical ant native to the lowland rainforests of Colombia's Pacific coast. The species belongs to the diligens group and is known only from the Bajo Calima region in Valle del Cauca department. Majors are small at just under 1mm in head width, with a slender body, smooth shiny pronotum, and reduced propodeal spines appearing as small denticles. The gaster is light to medium brown while the rest of the body and appendages are brownish yellow. Minors are even smaller at around 0.44mm head width, uniformly dark yellow, with foveolate (pitted) head sculpturing and a dentate propodeum. In the wild, they nest in rotten sticks and dead wood on the forest floor, a typical nesting preference for many Pheidole species in rainforest environments ^[1][2].

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Pacific lowland rainforest of Colombia, specifically the Bajo Calima region in Valle del Cauca department. They nest in rotten sticks and dead wood on the forest floor ^[1][2].
• Colony Type: Unconfirmed, colony structure (single-queen or multi-queen) has not been documented for this species. Most Pheidole species are monogyne (single queen) but some can form multi-queen colonies.
• Size & Growth:
  • Queen: Not documented for this species, typical Pheidole queens are 5-8mm
  • Worker: Major: 0.92mm head width, Minor: 0.44mm head width ^[2]
  • Colony: Unknown, likely similar to other small Pheidole species in the diligens group, possibly several hundred workers
  • Growth: Unknown, likely moderate based on typical Pheidole patterns
  • Development: Estimated 6-8 weeks based on typical Pheidole development at warm temperatures (Development time is unconfirmed for this specific species. Most Pheidole species develop from egg to worker in 6-8 weeks at optimal temperatures (24-28°C).)
• Antkeeping:
  • Temperature: Aim for 24-28°C, warm tropical conditions. A heating cable on one side of the nest creates a temperature gradient that allows ants to regulate their own exposure.
  • Humidity: Keep substrate moderately moist. Since they nest in rotten wood in rainforest habitats, they prefer damp but not waterlogged conditions. Provide a water tube and mist occasionally, allowing the nest to dry slightly between waterings.
  • Diapause: Unknown, being a tropical species from lowland Colombia, they likely do not require a true hibernation period. However, a slight cool-down during the dry season may be beneficial.
  • Nesting: Provide rotting wood pieces, cork bark, or a Y-tong/plaster nest with wood-like texture. They naturally nest in dead wood, so substrates that mimic this will be appreciated. Avoid completely dry nests.
• Behavior: These ants are small but active foragers. Pheidole species typically have well-developed major workers (soldiers) that assist with seed processing and colony defense. They are not aggressive toward keepers but majors may bite if threatened. Minor workers forage for food while majors typically remain in the nest. Their very small size means escape prevention must be excellent, they can squeeze through surprisingly small gaps. Expect active foraging behavior, particularly for protein sources.
• Common Issues: escape prevention is critical due to their very small size, use fine mesh and tight-fitting lids, humidity control can be tricky, too wet causes mold, too dry causes brood death, wild-caught colonies may harbor parasites that can decimate the colony in captivity, slow growth can lead to keeper impatience and overfeeding, which causes mold problems, rotten wood nesting substrate can develop mold if not properly managed

Nest Preferences and Housing

Pheidole calimana naturally nests in rotten sticks and dead wood on the rainforest floor. For captive care, you have several good options. A Y-tong (acrylic) nest works well, choose one with narrow chambers scaled to their tiny size. Alternatively, a plaster or soil nest with pieces of rotting wood embedded provides a more naturalistic setup that mimics their natural environment. Some keepers successfully keep them in test tube setups with a small piece of cork or wood as shelter. Regardless of nest type, ensure the substrate or nest material can hold some moisture, these ants come from a damp rainforest environment. Avoid completely dry setups. ^[2]

Feeding and Diet

Pheidole species are generalist omnivores that readily accept both protein and carbohydrate sources. Offer protein foods such as small insects (fruit flies, small crickets, mealworms), and minor workers will readily scavenge these. Sugar sources like honey water or sugar water are typically accepted. In the wild, they likely forage for honeydew from aphids and other small invertebrates. Feed every 2-3 days, removing uneaten prey to prevent mold. A constant supply of sugar water is recommended. Because of their very small size, portion sizes should be tiny, a drop of sugar water or a fragment of insect no larger than the ants themselves.

Temperature and Seasonal Care

As a tropical lowland rainforest species from Colombia, Pheidole calimana requires warm conditions. Maintain nest temperatures between 24-28°C. A heating cable placed on one side of the nest creates a gradient allowing ants to self-regulate. Room temperature may be sufficient if your home stays in this range, but monitor with a thermometer. Unlike temperate species, they do not require a true hibernation period. However, slight temperature fluctuations mimicking seasonal changes in their native habitat may be beneficial. Avoid temperatures below 20°C for extended periods. High humidity is important, aim for 60-80% relative humidity in the nest area. ^[1]

Behavior and Colony Dynamics

Pheidole calimana exhibits the typical Pheidole caste system with distinct minor and major workers. Minor workers are the foragers and care for brood, while major workers (soldiers) assist with food processing and colony defense. Majors have the characteristic enlarged heads of Pheidole majors but are small even for this genus. Colonies likely grow gradually, expect slow but steady growth over the first year. Workers are active foragers that will emerge quickly when food is introduced. They are not particularly aggressive but may bite if the nest is disturbed. The major workers' reduced propodeal spines (appearing as small denticles) indicate they rely more on biting than stinging for defense. ^[2]

Frequently Asked Questions

References