Temnothorax exilis

Temnothorax exilis

Temnothorax exilis is a small, variable ant belonging to the Myrmicinae subfamily. Workers measure around 3-4mm with a dark brown to nearly black body, though coloration ranges from yellow to black depending on the population ^[1]. This species lacks the metanotal groove (the groove between the middle and rear body sections) and has a distinctive high, flat-topped petiole node ^[1]. It belongs to the Palearctic clade and the exilis species group ^[2]. The species is widespread across the Mediterranean region from Portugal to Turkey, including many islands ^[1]. Colonies are found in soil under rocks or in rock crevices in sunny, dry, open habitats often covered in phrygana (Mediterranean scrubland) ^[1][3]. This species is notable for its extreme color variation, some populations are nearly black while others are pale yellow, and this variability extends even within single nest samples ^[4][5].

Quick Summary

• Difficulty: Easy
• Origin & Habitat: Mediterranean region, found across Southern Europe from Portugal and Spain to Turkey, including Corsica, Sardinia, Sicily, Crete, Malta, and Greece. Inhabits dry, rocky, open habitats with Mediterranean scrub (phrygana), always in sunny localities ^[1][3].
• Colony Type: Facultatively polygynous, colonies can have a single queen (monogyne) or multiple queens (polygyne) ^[1][3]. Some populations show obligate single-queen structure ^[6].
  • Colony: Optionally polygyne
  • Founding: Claustral
• Size & Growth:
  • Queen: Estimated 4-5mm based on genus typical size
  • Worker: 3-4mm (HL 0.581-0.671mm, HW 0.47-0.564mm) ^[1]
  • Colony: Likely under 500 workers based on typical Temnothorax colony sizes
  • Growth: Moderate
  • Development: 6-10 weeks (estimated based on typical Temnothorax development) (Development time follows typical Temnothorax patterns, temperature dependent, faster at warmer temperatures within Mediterranean range)
• Antkeeping:
  • Temperature: Keep at 20-26°C, they naturally inhabit warm Mediterranean climates and can tolerate higher temperatures. A gradient allowing warmer and cooler areas is ideal ^[7].
  • Humidity: Low to moderate, they prefer dry, sunny nesting sites. Keep substrate moderately dry, not waterlogged. Provide a small water source in the outworld.
  • Diapause: Yes, a winter rest period of 2-3 months at 10-15°C is recommended to simulate Mediterranean seasonal cycles ^[8].
  • Nesting: Naturalistic setups work best, they nest under stones or in rock crevices in the wild. Use a flat stone setup, Y-tong nest with narrow chambers, or a plaster nest with dry conditions. They prefer tight chambers scaled to their small size.
• Behavior: Generally peaceful and non-aggressive. Workers are small and active, foraging for nectar and small prey. They are known to be pollinator ants, documented pollinating Neotinea maculata orchids in Spain ^[9]. They can be escape risks due to their tiny size, use fine mesh barriers. They are known hosts for the parasitic ant Chalepoxenus sp. ^[10] and the fungus Myrmicinosporidium durum ^[11].
• Common Issues: escape prevention is critical due to their tiny 3mm size, use fine mesh and tight-fitting lids, colonies may fail if kept too humid, they prefer dry Mediterranean conditions, wild-caught colonies may carry parasites like Myrmicinosporidium durum that can affect survival ^[11], slow founding phase, claustral queens may take months before first workers appear, color variation in captive colonies is normal, wild populations range from yellow to black

Housing and Nest Setup

Temnothorax exilis is a tiny ant that needs appropriately scaled housing. In the wild, they nest in soil under medium-sized rocks or in rock crevices, always in sunny locations ^[1][3]. For captivity, naturalistic setups with flat stones work well, place the nest section under a flat stone on a layer of soil or plaster. Y-tong (AAC) nests with narrow chambers are also suitable. The key is providing dry to moderately humid conditions with a temperature gradient. Because of their tiny 3mm size, escape prevention must be excellent, use fine mesh on any ventilation and ensure all lids fit tightly. A small outworld for foraging completes the setup ^[7].

Feeding and Diet

Like most Temnothorax species, T. exilis is omnivorous. They accept sugar sources (honey water, sugar water) and protein (small insects like fruit flies, pinhead crickets, mealworms). In Spain, they have been documented as pollinators of orchids, visiting flowers for nectar ^[9]. Feed them a few times per week, offer protein once or twice weekly and keep a sugar source available in the outworld. Remove uneaten prey after 24 hours to prevent mold. Given their small size, prey items should be appropriately sized, very small insects or crushed insects work well.

Temperature and Seasonal Care

This is a Mediterranean species that naturally inhabits warm, dry, sunny habitats ^[4]. Keep them at room temperature (20-26°C) with a slight gradient if possible. They can tolerate warmer conditions than many temperate ants. During winter, provide a diapause (winter rest) period of 2-3 months at 10-15°C to simulate their natural seasonal cycle, this helps maintain colony health and may trigger reproductive behavior in spring ^[8]. The diapause mimics the cooler Mediterranean winter they experience in their native range.

Colony Founding

Queens are claustral, they seal themselves in a small chamber and raise their first workers without leaving to forage. The founding process follows typical Temnothorax patterns: the queen lays eggs, which develop through larvae and pupae to become workers (nanitics, first workers are typically smaller). This takes approximately 6-10 weeks at optimal temperatures. Founding colonies need quiet conditions and should not be disturbed. The queen will seal the founding chamber and rely on her stored fat reserves. Once the first workers emerge, they will begin foraging in the outworld. Colonies can be monogyne (single queen) or polygynous (multiple queens) in the wild ^[1][3].

Health and Common Problems

Watch for the fungal parasite Myrmicinosporidium durum, which has been documented infecting this species in Italy ^[11]. Infected workers may appear normal but carry spores visible through the body wall. The fungus typically affects colonies in late summer and fall, and infected workers often die after hibernation ^[11]. Due to their tiny size, escape prevention is critical, they can squeeze through remarkably small gaps. They prefer dry conditions, so avoid over-humidifying the nest. Color variation in captive colonies is completely normal, wild populations range from nearly yellow to completely black, and this variability exists even within single populations ^[4][5].

Behavior and Temperament

Temnothorax exilis is a peaceful, non-aggressive species. Workers are small and active, typically foraging individually for nectar and small prey. They are known to be pollinators, research in Spain documented them visiting and pollinating Neotinea maculata orchids ^[9]. They do not have a functional stinger (Myrmicinae subfamily uses chemical defenses instead). Colonies are relatively calm and do not exhibit aggressive swarming behavior when disturbed. They are known hosts for the socially parasitic ant Chalepoxenus species ^[10], which is a natural part of their ecology in the wild.

Frequently Asked Questions

References