Polyergus longicornis

Polyergus longicornis - "Long-horned Amazon Ant"

Polyergus longicornis is a striking red ant native to the southeastern United States, ranging from the Carolinas west to Mississippi. These medium-sized ants reach about 6.4-7.3mm in total length, with workers recognizable by their long scapes (the antennae segments extending from the head) that surpass the corners of their head, and a matte red body with darker legs and abdominal tip ^[1]. What makes this species extraordinary is its lifestyle as an obligate slave-maker, P. longicornis cannot survive without a host colony of Formica dolosa ants, which they raid to steal young brood that emerge as workers to serve the parasite colony ^[2]. This species is distinguished from similar Polyergus by its abundant vertex pilosity (20-40 erect hairs on the head) and exclusively uses F. dolosa as its host ^[3].

Quick Summary

• Difficulty: Expert
• Origin & Habitat: Southeastern United States, Carolinas, Georgia, and Mississippi. Found in open pinelands and oak-pine woodlands on sandy soils ^[1][3].
• Colony Type: Single-queen colonies (monogyne). The queen is an obligate social parasite that must invade a Formica dolosa colony, kill the host queen, and use host workers to raise her brood. Mixed colonies contain both Polyergus workers and their Formica slaves ^[2].
  • Colony: Monogyne
  • Queen: Socially parasitic
  • Special: Slave-making
• Size & Growth:
  • Queen: Weber's length approximately 3.78 mm ^[2]. Queens are similar in size to F. dolosa queens.
  • Worker: 6.44-7.32 mm total length ^[1]. HL 1.60-1.80mm, HW 1.52-1.72mm ^[1].
  • Colony: Mixed colonies can reach over 700 workers total. Polyergus workers typically comprise 12-20% of the total worker count ^[2].
  • Growth: Moderate, depends on host colony success
  • Development: Unknown, development occurs within the host colony. Related Polyergus species suggest 6-10 weeks at optimal temperature. (Development is tied to host colony brood development. The host Formica workers raise the Polyergus brood.)
• Antkeeping:
  • Temperature: Keep around 22-26°C. As a southeastern species, they prefer warm conditions similar to their native pine flatwoods habitat.
  • Humidity: Moderate humidity,50-60%. Sandy soil habitats indicate they prefer drier conditions than many ants.
  • Diapause: Likely requires winter dormancy. Southeastern US populations experience mild winters, a cool period around 10-15°C for 2-3 months is recommended.
  • Nesting: Y-tong or acrylic nests work well. The key requirement is maintaining a healthy host Formica dolosa colony alongside the Polyergus colony. Provide connections between the two nests so host workers can forage and tend to both colonies.
• Behavior: Polyergus workers are aggressive and dominate their Formica hosts. They primarily engage in self-grooming and raiding behavior, with occasional trophallaxis (food sharing) with host workers ^[2]. Workers are mildly polymorphic (varying sizes). They are not particularly escape-prone but standard barriers are still recommended. The species is obligately dulotic, they cannot survive without their host species. This is NOT a species for beginners due to the complexity of maintaining two colonies.
• Common Issues: Maintaining a host Formica dolosa colony is the critical challenge, without healthy host workers, the Polyergus colony will die, Mixed colonies require careful management to ensure both species thrive, These ants cannot be kept alone, they require a host colony to function, Escaped Polyergus without host workers will not survive, Finding Formica dolosa as host may be difficult depending on your location

Understanding the Slave-Making Lifestyle

Polyergus longicornis is an obligate dulotic ant, this means it is completely dependent on its host species (Formica dolosa) to survive. Unlike typical ants where the queen raises her first workers alone, a Polyergus queen must invade an established Formica colony, kill or replace the host queen, and use host workers to raise her brood ^[2]. The host workers then continue their normal foraging and colony maintenance behaviors, but now they serve the Polyergus queen instead of their original queen. In mixed colonies, Polyergus workers make up only 12-20% of the total worker population, the rest are enslaved Formica workers ^[2]. This makes P. longicornis one of the most challenging ant species to keep, as you must maintain two healthy colonies simultaneously.

Housing Requirements

You will need two separate but connected nest setups: one for your Polyergus longicornis colony and one for a healthy Formica dolosa host colony. Y-tong (acrylic) nests work well for both, with tubes connecting them so host workers can move between nests. This connection is critical, host workers must be able to forage for food and tend to both colonies. Keep the nests at similar temperatures (22-26°C) and provide moderate humidity. The host colony will need more space as Formica dolosa colonies can grow quite large. Ensure both colonies have access to water and protein food sources. ^[2]

Feeding Your Mixed Colony

The enslaved Formica workers do all the foraging, so food should be provided to the host colony side of your setup. Offer standard ant foods: protein sources like mealworms, crickets, and other small insects, plus sugar sources like honey water or sugar water. The Formica workers will consume these and share food through trophallaxis (mouth-to-mouth sharing) with both the Polyergus queen and workers ^[2]. Fresh water should always be available. Because the host workers do the foraging, ensure food is accessible to them, place prey items near the host nest entrance.

The Raid: How They Acquire Slaves

In the wild, Polyergus colonies conduct spectacular raids on nearby Formica dolosa nests. Workers march in a column (often around 100 individuals) toward a host colony, infiltrate it, and steal pupae and larvae ^[4]. These stolen brood are carried back to the Polyergus nest where they emerge as adult Formica workers that know no other queen, they instinctively tend the Polyergus queen and her brood as if they were their own. In captivity, you can simulate this by carefully introducing some Formica dolosa workers or brood from a separate colony to your Polyergus nest. Success requires patience and careful introduction.

Seasonal Care and Overwintering

As a southeastern US species, P. longicornis experiences mild winters but does require a cool period. Reduce temperatures to around 10-15°C for 2-3 months during winter, mimicking natural seasonal cycles. Both the Polyergus and host colonies should be cooled together. Reduce feeding during this period but ensure water is always available. In summer, the warm temperatures of their native pine flatwoods (25-30°C) can be simulated with a heating cable on one side of the nests, creating a temperature gradient the ants can choose from. ^[1][3]

Legal and Ethical Considerations

Polyergus longicornis is native to the southeastern United States. If you collect them, ensure you have permission and follow local regulations. These ants should NEVER be released outside their native range, they are obligate parasites that cannot survive without their specific host (Formica dolosa), and introducing them to new areas could harm native ant communities. If you can no longer keep your colony, contact a local ant keeper or entomology department rather than releasing them. Finding a legitimate source for both P. longicornis and F. dolosa may require connecting with experienced ant keepers or researchers. ^[3]

Frequently Asked Questions

References