Strongylognathus silvestrii

Strongylognathus silvestrii

Strongylognathus silvestrii is a small Myrmicinae ant native to the eastern Mediterranean, found in Greece (Rhodes, Crete, Dodecanese) and Turkey ^[1][2][3]. Workers are tiny, measuring around 0.7mm in head width, with a slimmer build compared to related species and relatively small propodeal spines ^[4]. The head sculpturing is minimal with only faint striae near the eyes, and the petiole and postpetiole are mostly smooth and shiny ^[4]. This species is a social parasite, a slave-maker that invades nests of Tetramorium ants (particularly T. semilaeve and T. diomedeum) and uses the host workers to raise its own brood ^[5][6]. The species was described from Rhodes Island in 1936 and shows considerable variation across its limited range ^[7].

Quick Summary

• Difficulty: Expert
• Origin & Habitat: Eastern Mediterranean region, Greece (Rhodes, Crete, Dodecanese) and Turkey. Found in dry, rocky Mediterranean habitats at elevations from sea level to 1100m ^[2][7].
• Colony Type: Social parasite (dulosis/slave-making). This species cannot found colonies independently, it requires a host Tetramorium colony to survive. The parasite queen invades a host nest, kills or replaces the host queen, and uses the host workers to raise her brood ^[6].
  • Colony: Monogyne
  • Queen: Socially parasitic
  • Special: Slave-making
• Size & Growth:
  • Queen: Unconfirmed, estimated similar to other Strongylognathus species at 4-5mm based on genus patterns
  • Worker: Approximately 2.5-3mm total length (HL ~0.77mm, HW ~0.67mm) ^[4]
  • Colony: Unknown for established colonies, likely small given parasitic lifestyle
  • Growth: Unknown, dependent on host colony success
  • Development: Unconfirmed, no direct data available (Development is entirely dependent on host colony resources. Strongylognathus workers emerge from the host nest alongside host workers.)
• Antkeeping:
  • Temperature: Mediterranean species, keep at 22-26°C range. Provide a temperature gradient allowing the colony to self-regulate.
  • Humidity: Low to moderate, dry Mediterranean conditions. Keep nest substrate moderately dry, similar to typical Tetramorium habitat.
  • Diapause: Likely yes, Mediterranean species typically require a mild winter rest period of 2-3 months at 10-15°C. This aligns with the seasonal cycle of their Tetramorium hosts.
  • Nesting: This is a parasitic species that must be kept WITH a host Tetramorium colony. The two colonies should be connected via a tube or bridge, allowing host workers to move between nests. Use test tubes or small acrylic nests scaled to the tiny worker size.
• Behavior: Slave-making ant. S. silvestrii workers cannot survive without host workers, they do not forage for themselves but rely on host workers to feed them and tend to their brood ^[6]. The parasite colony is typically smaller than the host component. Workers are not aggressive but the colony depends on the parasitic relationship for survival. Escape risk is low given their tiny size, but they remain within the nest area dominated by host workers.
• Common Issues: Cannot establish colony without live host, you must maintain both S. silvestrii and a Tetramorium host colony simultaneously, Host colony health is critical, if the Tetramorium colony dies, the parasite colony will also die, Finding a legal host species, T. semilaeve or similar species may not be readily available, Colony balance, parasite colonies are typically smaller and may be outcompeted if host colony grows too large, Specialized care requirements, this is not a beginner species and requires understanding of parasitic ant biology

Understanding the Parasitic Lifestyle

Strongylognathus silvestrii is a dulotic ant, a slave-maker that cannot survive independently. Unlike typical ants where workers forage for food and tend their own brood, S. silvestrii relies entirely on workers from its host species (Tetramorium semilaeve and related species) to survive ^[6]. The parasite queen enters a host nest, typically kills or displaces the host queen, and then uses the host workers to raise her own offspring. This means keeping S. silvestrii is fundamentally different from keeping most ant species, you are actually maintaining two colonies that must coexist. The S. silvestrii workers cannot feed themselves and depend on host workers for nutrition and brood care. This relationship has been stable evolutionarily, but it makes captive husbandry significantly more challenging than standard ant species ^[5].

Housing Requirements - The Dual Colony System

Keeping S. silvestrii requires maintaining both the parasite colony AND a healthy host Tetramorium colony. The two nests should be connected via tubing that allows host workers to move freely between them. This mimics the natural situation where both species share a single nest. For the Tetramorium host, use standard Myrmicinae setup, test tubes with water reservoirs work well, or small acrylic nests. The S. silvestrii portion can be in a separate connected chamber, but they will remain mostly within the host nest area. Both colonies need appropriate humidity (low to moderate, Mediterranean conditions) and temperature (22-26°C). The key principle is that the HOST colony's needs come first, if the host colony thrives, the parasite will thrive alongside it. Do not separate the colonies permanently as S. silvestrii workers cannot survive independently. ^[5][7]

Feeding and Nutrition

Feeding S. silvestrii is indirect, you feed the host Tetramorium colony, and the host workers then feed the parasite workers and brood. Offer the host colony standard Tetramorium foods: small protein sources (fruit flies, small crickets, mealworms) and sugar sources (honey water, sugar water). The host workers will distribute food to both their own brood and the S. silvestrii brood, and will also feed the parasite workers directly through trophallaxis (mouth-to-mouth food sharing). Do not expect to see S. silvestrii workers foraging, they typically remain in the nest area while host workers handle all external activities. Ensure food is offered in the host portion of the setup and that the host colony has constant access to a sugar source. ^[6]

Temperature and Seasonal Care

As a Mediterranean species from Greece and Turkey, S. silvestrii and its host prefer warm, relatively dry conditions. Maintain temperatures in the 22-26°C range, with a slight gradient if possible. During the winter months (roughly November through February in the northern hemisphere), both colonies will benefit from a cooling period at 10-15°C to simulate Mediterranean winter conditions. This diapause period is important for the health of both species and aligns with their natural seasonal cycle. Reduce feeding during this period and minimize disturbance. In summer, ensure the setup is not exposed to direct sunlight or excessive heat that could dry out the nests. ^[7][1]

Obtaining and Establishing a Colony

S. silvestrii colonies are not commonly available in the antkeeping hobby due to their parasitic nature. If available, they typically come as an established mixed colony with host workers. When establishing a new colony, you need both the parasite queen with her workers AND a healthy Tetramorium host colony. The two components should be introduced carefully, ideally, introduce the parasite queen to an established host colony rather than the reverse. The parasite queen may need to kill the host queen to take over the nest. This process can be stressful and success is not guaranteed. Wild-colony collection is difficult as S. silvestrii is rare and localized. Always ensure any host species used is legally and ethically obtained, avoid collecting from protected areas. ^[6][7]

Frequently Asked Questions

References