Cylindromyrmex whymperi

Quick Summary

• Difficulty: Expert
• Origin & Habitat: Neotropical forests from Guatemala to Chile, including the Galapagos Islands. Found in dead branches, rotting wood, and termite galleries in forest understories ^[1][3][4].
• Colony Type: Colony structure unconfirmed. Single dealate queen observed in field collections from a raiding column with about 100 workers ^[2].
• Size & Growth:
  • Queen: 7.58-8.16 mm ^[1]
  • Worker: 5.02-7.40 mm ^[1]
  • Colony: At least 100 workers observed during field raids, larger colonies likely exist ^[2]
  • Growth: Unknown
  • Development: Unknown, development timeline has not been scientifically documented for this species. (No direct measurements available.)
• Antkeeping:
  • Temperature: Keep at 24-28°C. As a neotropical species, they require warm conditions. A heating cable on one side of the nest creates a suitable gradient ^[2].
  • Humidity: High humidity required, these forest ants need moist substrate. Keep nest material damp but not waterlogged. Provide a water tube for drinking ^[2].
  • Diapause: No, being a tropical species, they do not require hibernation. Maintain warm temperatures year-round.
  • Nesting: In captivity, provide nests in rotting wood, cork, or plaster setups that retain moisture. They naturally nest in dead branches and termite galleries, so a naturalistic setup with wood pieces works well. Ensure chambers are appropriately sized for 5-7mm workers ^[3][4].
• Behavior: Cylindromyrmex whymperi is an aggressive predator specializing in termite hunting. Workers display mass trail recruitment, when a forager finds prey, it returns to the nest and recruits large numbers of nestmates using pheromone trails ^[2]. They are not aggressive toward keepers but will sting if threatened. Workers continuously drag their abdomen while walking, depositing trail pheromones. They are moderately active and will establish visible foraging trails. Escape risk is moderate, use standard barrier methods ^[2].
• Common Issues: specialized diet makes them difficult to feed, they strongly prefer termites and may refuse other prey, small colony sizes in captivity can be fragile and sensitive to disturbance, high humidity requirements can lead to mold if ventilation is poor, limited availability in the antkeeping hobby makes establishing colonies challenging, wild-caught colonies may carry parasites that can devastate captive populations

Housing and Nest Setup

Cylindromyrmex whymperi requires a naturalistic setup that mimics their natural habitat in rotting wood and termite galleries. Use a formicarium with wood pieces, cork, or a plaster nest that retains moisture. The chambers should be appropriately sized for workers that are 5-7mm. Connect the nest to a foraging arena where you can observe their hunting behavior. Because they frequently relocate in the wild, they may benefit from having multiple potential nest sites available ^[3][4]. Keep the nest humid but ensure adequate ventilation to prevent mold. A water tube should always be available.

Feeding and Diet - Critical

This is the most challenging aspect of keeping C. whymperi. Laboratory studies show they are highly specialized termite predators. Workers readily recruited to dead termites but showed NO interest in crickets, cockroaches, or sugar water, they refused these foods entirely even when placed directly in the nest ^[2]. You must provide live or freshly killed termites for successful keeping. Termites from the genus Reticulitermes or Cryptotermes work well. Other small insects may be accepted experimentally, but do not rely on them. This specialized diet makes C. whymperi unsuitable for beginners ^[2]. Feed termites every few days and remove uneaten prey promptly.

Mass Recruitment Behavior

One of the most fascinating aspects of C. whymperi is their sophisticated recruitment system. When a single worker discovers a termite colony, it returns to the nest and recruits nestmates by laying a pheromone trail. The trail pheromone comes from a unique gland between abdominal sternites 6 and 7, each worker has its own individual reservoir chamber for storing this chemical, a structure not found in any other ant species ^[2]. Workers drag their abdomen continuously while walking, depositing the pheromone. Within 10 minutes of discovering prey, dozens of workers will exit the nest and follow the trail ^[2]. In captivity, you can observe this dramatic behavior by providing termites as prey.

Temperature and Seasonal Care

As a neotropical species from Central and South America, C. whymperi requires warm temperatures year-round. Keep the nest at 24-28°C. A small heating cable placed on one side of the nest creates a temperature gradient allowing workers to regulate their own exposure. They do not require hibernation or diapause, maintain consistent tropical conditions throughout the year. The Galapagos Islands population experiences warm, relatively stable temperatures, so avoid temperature drops below 22°C. Monitor with a thermometer placed near the nest ^[2].

Defense and Handling

Cylindromyrmex whymperi workers possess a functional stinger and will use it if threatened. While the sting is not dangerous to healthy humans, it can be painful and may cause localized irritation. These ants are not aggressive toward keepers and will focus on their hunting activities rather than investigating disturbances. Standard escape prevention methods work well, their medium size means they cannot squeeze through typical barrier gaps. Always handle colonies gently as they are sensitive to vibration and disturbance, especially smaller colonies ^[2].

Galapagos Distribution Note

C. whymperi is found on several Galapagos Islands including Baltra, Fernandina, Isabela, Santa Cruz, and Santiago. Its origin on the islands is uncertain, it may be native or may have been introduced ^[3]. Notably, it appears to have been displaced by the invasive fire ant Wasmannia auropunctata on Santa Cruz Island ^[3][5]. If you keep this species, never release specimens in the Galapagos or similar tropical islands where they are not native, as they could become invasive.

Frequently Asked Questions

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References