Temnothorax andrei

Temnothorax andrei

Temnothorax andrei is a small, light yellow to brown ant native to western North America, ranging from Washington down through California, Nevada, Arizona, New Mexico, and into Mexico's Baja California ^[1][2]. Workers are tiny at around 2-3mm, with a 12-segmented antenna and distinctive striated head sculpture ^[3]. This species belongs to the andrei-clade, which is exclusively western and southwestern North American ^[4]. They inhabit relatively dry environments including oak woodland, coniferous forest, pinyon-juniper, and cool desert areas ^[3][5]. Colonies are small, typically containing fewer than 100 workers, and nest under stones or in the interstitial spaces between rocks ^[3]. One of the most remarkable traits of this species is its ability to persist even when invasive Argentine ants have invaded, it's one of only two native ant species documented surviving after Argentine ant invasion in California ^[6][7].

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Western North America, found in Washington, California, Nevada, Arizona, New Mexico (USA) and Baja California Norte (Mexico) ^[2][8]. Inhabits dry habitats including oak woodland, dry coniferous forest, laurel forest, pinyon-juniper woodland, and cool deserts ^[3][5]. Common at low to medium elevations from 0-1800m ^[1].
• Colony Type: Small colonies with typically fewer than 100 workers ^[3]. Polygynous colony structure has been documented in some populations, meaning multiple queens can coexist in a single colony ^[9]. Colonies are often found nesting under stones or in rock crevices.
  • Colony: Optionally polygyne
  • Founding: Claustral
• Size & Growth:
  • Queen: Estimated 5-6mm based on genus typical sizes
  • Worker: Approximately 2-3mm ^[3]
  • Colony: Up to 100 workers ^[3]
  • Growth: Slow to moderate, small colonies grow gradually
  • Development: Estimated 6-10 weeks based on typical Temnothorax development (Development time is inferred from related Temnothorax species as specific timing has not been documented for T. andrei)
• Antkeeping:
  • Temperature: Keep at room temperature around 18-24°C. This species is documented as a cold-climate specialist in some parts of its range ^[10], so avoid overheating. A temperature gradient allows workers to choose their preferred zone.
  • Humidity: Prefers dry to moderate conditions, their natural habitats are relatively dry. Keep nest substrate lightly moist but allow it to dry out partially between waterings. Avoid overly damp conditions that would cause mold.
  • Diapause: Yes, as a temperate species from higher elevations and latitudes, they need a winter rest period. Reduce temperature to around 10-15°C for 2-3 months during winter.
  • Nesting: Use a naturalistic setup with flat stones or a Y-tong/plaster nest with narrow chambers. They naturally nest under stones or in rock crevices ^[3]. Tight chambers scaled to their tiny size work well.
• Behavior: These ants are relatively docile and not aggressive. Workers are small but active foragers. They are ground-dwelling and prefer to nest in tight spaces under stones or in rock gaps ^[11]. Their tiny size means escape prevention is critical, they can squeeze through small gaps. They are generalist foragers and can coexist with invasive species due to their small size and cryptobiotic nature ^[7].
• Common Issues: escape prevention is critical due to their very small size, use fine mesh and tight-fitting lids, small colony size means slow growth, don't expect rapid population increases, overheating can be fatal, keep away from direct heat sources, wild-caught colonies may have parasites that can cause colony failure, dry habitats mean they are sensitive to excess moisture, avoid waterlogging the nest

Housing and Nest Setup

Temnothorax andrei is a tiny ant that needs appropriately scaled housing. In the wild, they nest under stones or in the small gaps between rocks ^[3][5]. For captivity, a Y-tong (AAC) nest or plaster nest with narrow chambers works well. The chambers should be tight, these ants feel secure in snug spaces. A naturalistic setup with flat stones placed on moist substrate can also work, but you'll need excellent escape prevention since they can slip through the tiniest gaps. Test tube setups are suitable for founding colonies, but monitor water levels as these dry-habitat ants are sensitive to flooding. Whatever nest type you choose, ensure the outworld has good escape prevention, a barrier of fluon on the rim and fine mesh covering any ventilation holes.

Feeding and Diet

Temnothorax andrei is a generalist forager that will accept a variety of foods. Offer sugar water or honey as an energy source, and protein sources like small insects (fruit flies, small mealworms, pinhead crickets). In the wild, they forage for honeydew and small arthropods. Feed them small prey items that they can subdue, their tiny workers can't tackle large insects. A small drop of honey or sugar water should be offered 2-3 times per week, with protein prey once or twice weekly. Remove any uneaten prey after 24 hours to prevent mold. Because colonies stay small (under 100 workers), don't overfeed, excess food can mold and harm the colony. ^[7]

Temperature and Seasonal Care

This species is documented as a cold-climate specialist in parts of its range ^[10], so moderate temperatures are ideal. Keep the nest area at 18-24°C, room temperature is usually fine. Avoid placing nests near heat sources that could cause overheating. During winter, they need a diapause period. Reduce temperatures to 10-15°C for 2-3 months, mimicking natural seasonal cycles. You can accomplish this by moving the colony to a cooler location like a garage or basement (as long as it stays above freezing). Reduce feeding during this period. In summer, ensure the colony isn't exposed to direct sunlight or hot conditions. The elevation range of 0-1800m in California suggests they can handle a range of conditions but prefer cooler temperatures than many tropical ants.

Colony Structure and Multi-Queen Behavior

Temnothorax andrei has documented polygynous colony structure in some populations, meaning multiple queens can coexist in a single colony ^[9]. This is unusual among ants and means your colony might start with more than one queen if you acquire a wild colony. Colonies remain small, typically under 100 workers ^[3]. If you have a polygynous colony, the presence of multiple egg-laying queens can help the colony survive if one queen dies. However, this also means growth is spread among multiple reproductives rather than concentrated. When starting from a single founding queen, expect slow growth as she raises her first nanitic workers alone. The small colony size means you'll need patience, these aren't ants that will rapidly fill a large formicarium.

Dealing with Invasive Ants

One of the most interesting traits of Temnothorax andrei is its ability to persist even when invasive Argentine ants (Linepithema humile) have invaded an area. Studies show it's one of only two native ant species that remained after Argentine ant invasion in California ^[6][7]. This resilience comes from their small size and cryptobiotic (hidden) nature, they compete with the invasive species for less nesting space and food resources ^[7]. If you're keeping this species, this tells you they're adaptable and can handle some competition. However, in captivity, you should still keep them isolated from other ant species to prevent stress or predation on their small workers.

Unique Nesting Associations

In the wild, Temnothorax andrei sometimes exhibits plesiobiosis, a nesting association where two species nest in close proximity without direct interdependence. They've been found living alongside Camponotus yogi, using the same plant stems (chaparral, in living stems of Haplopappus pinifolius) ^[12]. They've also been documented living within Camponotus and Formica nests ^[3]. This flexibility in nesting associations suggests they're adaptable to different nest environments. In captivity, provide them with the tight, enclosed spaces they naturally prefer, under stones or in rock crevices. They don't require host colonies, but this information explains why they can sometimes be found in unusual nesting situations in the wild.

Frequently Asked Questions

References