Temnothorax andrei

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Western North America, found in Washington, Oregon, California, Nevada, Arizona, New Mexico (USA), Baja California Norte and Baja California Sur (Mexico), also recorded from Colorado and Sonora ^{[2][11][4][12]}. Inhabits dry habitats: oak woodland, dry coniferous forest, laurel forest, pinyon-juniper woodland, and cool deserts ^[5][7]. Common at low to medium elevations from 0-1800 m ^[1]. Also found on serpentine soils and in urban parks ^[8][10].
• Colony Type: Facultatively polygynous, some populations have multiple queens, while others have a single queen. Colonies remain small, usually under 109 workers ^[3][5].
• Size & Growth:
  • Queen: Size data unavailable, inferred from Temnothorax genus (~5-6 mm)
  • Worker: ~2.25 mm total length ^[5]
  • Colony: Up to 109 workers (based on Cole 1958,though sample size was small) ^[5]
  • Growth: Slow to moderate
  • Development: Estimated 6-10 weeks (based on related Temnothorax species, specific timing not documented for T. andrei) (Development time depends on temperature, founding queens brood alone.)
• Antkeeping:
  • Temperature: Keep at room temperature, roughly 18-24 °C. This species is a cold-climate specialist in parts of its range ^[13], so avoid overheating. A temperature gradient allows workers to choose their preferred zone ^[1].
  • 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 waterlogging.
  • Diapause: Yes, as a temperate species with a wide elevation range ^[1], they likely need a winter rest period. Reduce temperature to around 10-15 °C for 2-3 months during winter. This can be achieved by moving the colony to a cooler location (above freezing). Reduce feeding during this period.
  • Nesting: Use a naturalistic setup with flat stones or a Y‑tong/plaster nest with narrow chambers. In the wild they nest under stones or in rock crevices ^[5][7]. Tight chambers scaled to their tiny size work well.
• Behavior: These ants are relatively docile and not aggressive. Their primary defense is smearing venom from a modified stinger (subfamily Myrmicinae, tribe Crematogastrini). Workers are small but active foragers, ground‑dwelling, and often cryptic ^[10]. They are generalist foragers and can persist alongside invasive Argentine ants due to their small size and hidden nesting habits ^[10]. Their tiny size means escape prevention is critical, they can squeeze through small gaps.
• Common Issues: escape prevention is critical due to very small size, use fine mesh and tight-fitting lids, small colony size makes them vulnerable to setbacks and growth is slow, overheating can be fatal, keep away from direct heat sources, excess moisture is harmful, their natural habitat is dry, wild-caught colonies may carry parasites that can cause collapse

Housing and Nest Setup

Temnothorax andrei needs appropriately scaled housing. In the wild, they nest under stones or in small gaps between rocks ^[5][7]. For captivity, a Y‑tong (AAC) 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. 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 accepts a variety of foods ^[10]. Offer sugar water or honey as an energy source, and protein like small insects (fruit flies, small mealworms, pinhead crickets). In the wild, they forage for honeydew and small arthropods. Feed them small prey items they can subdue, tiny workers can't tackle large insects. Offer a small drop of honey or sugar water 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 (up to 109 workers), don't overfeed, excess food can cause mold.

Temperature and Seasonal Care

This species is documented as a cold-climate specialist in parts of its range ^[13], and occurs from 0 to 1800 m elevation ^[1]. Keep the nest area at 18-24 °C, room temperature is usually fine. Avoid placing nests near heat sources. During winter, they need a diapause period. Reduce temperatures to 10-15 °C for 2-3 months, mimicking natural seasonal cycles. You can move 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.

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 ^[3]. This means your colony might start with more than one queen if you acquire a wild colony. Colonies remain small, typically up to 109 workers ^[5]. If you have a polygynous colony, multiple egg‑laying queens can help the colony survive if one queen dies. However, this also means growth is spread among multiple reproductives. When starting from a single founding queen, expect slow growth as she raises her first nanitic workers alone. Be patient, these ants won't 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 ^[9][10]. This resilience comes from their small size and cryptobiotic (hidden) nesting, they compete for less nesting space and food ^[10]. If you're keeping this species, this tells you they're adaptable and can handle some competition. In captivity, keep them isolated from other ant species to prevent stress or predation.

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) ^[14]. They've also been documented living within Camponotus and Formica nests ^[5]. This flexibility suggests they're adaptable to different nest environments. In captivity, provide them with tight, enclosed spaces under stones or in rock crevices. They don't require host colonies.

Reproduction and Nuptial Flights

Sexuals (alates) have been found in nests during June and July (Cole 1958,reported in AntWiki) ^[5]. The exact timing of nuptial flights is not well documented, but likely occurs during summer (June-August) based on this observation. Founding behavior is unconfirmed, no studies report whether queens found colonies independently (claustral) or by other means. Captive colonies started from a single queen may show claustral founding, but this has not been verified for this species.

Frequently Asked Questions

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References