Calomyrmex similis

Calomyrmex similis

Calomyrmex similis is a medium-sized ant species in the subfamily Formicinae, originally described by Mayr in 1876 from Queensland, Australia. Workers display the typical Formicinae body plan with a single waist segment (petiole) and a acid-producing gland instead of a stinger. The genus Calomyrmex contains about 14 described species, all distributed primarily in the Australasian region. This species has been recorded from Australia and, more unusually, from China, suggesting either a broader distribution than typically recognized or possible taxonomic confusion that warrants further study ^[1][2].

This is a poorly documented species in the scientific literature, and much of what follows is inferred from related ants in the Camponotini tribe. Calomyrmex belongs to the same tribe as the well-known Camponotus carpenter ants, and they share many biological traits with that group. In captivity, they are likely to be moderate-sized ants with typical Formicinae behaviors including formic acid defense and claustral colony founding.

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Queensland, Australia, dry to subtropical forest environments. The type localities are Rockhampton and Gayndah in coastal Queensland ^[1].
• Colony Type: Likely single-queen (monogyne) colonies based on typical Camponotini patterns, though this is unconfirmed for this specific species.
  • Colony: Monogyne
  • Founding: Claustral
• Size & Growth:
  • Queen: Estimated 8-10mm based on genus and related Camponotini species
  • Worker: Estimated 5-7mm based on genus and related Camponotini species
  • Colony: Unknown, likely several hundred workers based on typical Calomyrmex colony sizes
  • Growth: Moderate, estimated based on related Formicinae patterns
  • Development: Estimated 6-10 weeks at optimal temperature based on typical Camponotini development (Development time is estimated from related species, specific data for C. similis is unavailable)
• Antkeeping:
  • Temperature: Keep at 22-26°C. Australian species generally tolerate room temperature well. A gentle gradient allowing workers to choose their preferred temperature is ideal.
  • Humidity: Moderate humidity around 50-60%. These are not rainforest ants, allow the nest to dry partially between waterings.
  • Diapause: Likely required. Australian ants typically need a winter rest period of 8-12 weeks at 10-15°C. Monitor colony activity, if workers become sluggish in winter, begin hibernation.
  • Nesting: Accepts most standard nest types. Y-tong (AAC), plaster, or acrylic nests work well. Provide a dry nest chamber with access to a water tube. Naturalistic setups with soil or sand are also suitable.
• Behavior: Temperament is likely moderate, they will defend the colony but are not particularly aggressive. Like other Formicinae, they can spray formic acid as a defense mechanism. Workers are moderately active foragers. Escape prevention should be standard, while not among the smallest ants, they can still escape through small gaps. Use fluon on test tube rims and ensure formicarium connections are secure.
• Common Issues: limited scientific data means care recommendations are largely inferred from related species, colony growth may be slow, avoid the temptation to overfeed or disturb the queen during founding, hibernation requirements are estimated and may need adjustment based on your colony's behavior, wild-caught colonies may carry parasites, quarantine and monitor new colonies, formic acid defense can irritate eyes, handle gently and wash hands after contact

Nest Preferences

Calomyrmex similis likely prefers dry to moderately humid nesting sites. In the wild, they probably nest in soil, under stones, or in rotting wood, typical locations for Camponotini ants. For captive colonies, Y-tong (AAC) nests work very well because they provide a dark, secure space that ants can easily defend. Plaster nests are also suitable, especially if you want to maintain moderate humidity. Test tube setups work for founding colonies, simply place the queen in a test tube with a water reservoir and seal the open end with cotton. The queen will seal herself in and raise her first brood claustrally. Once the colony reaches 20-30 workers, consider moving to a larger formicarium. Always provide a water source connected to the nest so workers can hydrate without leaving the foraging area.

Feeding and Diet

Like other Formicinae ants, Calomyrmex similis is likely omnivorous with a preference for protein sources. In captivity, offer a varied diet including protein-rich foods like small insects (fruit flies, pinhead crickets, mealworms), and sugar sources such as honey water, sugar water, or commercial ant nectar. Workers will collect honeydew from aphids if available. Feed protein 2-3 times per week, and keep a sugar source available at all times. Remove uneaten prey after 24-48 hours to prevent mold. During founding, the queen will not eat, she relies entirely on her stored fat reserves. Once workers emerge, they will begin foraging and can accept food offerings.

Temperature and Seasonal Care

Maintain nest temperatures between 22-26°C. This species should do well at typical room temperature (20-23°C), but providing a slight warmth (around 24-26°C) may accelerate brood development. Use a heating cable or heating mat on one side of the nest to create a temperature gradient, this allows workers to self-regulate by moving between warmer and cooler areas. For overwintering, simulate Australian winter conditions with 8-12 weeks at 10-15°C. This can be achieved in a basement, garage, or refrigerator (using a thermometer controller). Reduce feeding during hibernation and keep the nest slightly moist but not wet. Do not feed during deep hibernation. Monitor your colony, if workers remain active and alert, they may not need full hibernation, but most Australian ants benefit from a cool period.

Behavior and Defense

Calomyrmex ants are in the subfamily Formicinae, which means they lack a stinger. Instead, they defend themselves by spraying formic acid, a pungent liquid that can irritate skin and eyes. When threatened, workers may raise their abdomen and spray at the perceived threat. This is not dangerous to healthy humans but can be unpleasant. Wash your hands after handling and avoid getting formic acid in your eyes. In terms of temperament, they are not particularly aggressive but will protect their nest vigorously. Workers are likely moderate foragers, searching for food both on the ground and on low vegetation. They probably establish well-defined foraging trails once the colony is established.

Frequently Asked Questions

References