Linepithema micans

Linepithema micans

Linepithema micans is a small Dolichoderine ant native to South America, ranging from central Argentina to eastern Brazil. Workers measure 2.5-4mm with a variable color scheme ranging from light brown to dark brown, featuring dense pubescence and distinctive standing hairs on the first two abdominal segments. This species is closely related to the infamous Argentine ant (Linepithema humile) but is a distinct species that has often been confused with it in scientific literature. Queens are moderately large at 1.55-2.38mm mesosomal length and colonies typically contain multiple queens. In their native range, these ants are significant agricultural pests in vineyards where they mutually associate with a soil scale insect (Eurhizococcus brasiliensis) that damages grapevines, the ants protect and disperse this harmful scale insect in exchange for honeydew. Colonies are ground-nesting and forage primarily from dusk through morning, avoiding the hottest hours of the day.

Quick Summary

• Difficulty: Easy
• Origin & Habitat: South America, from central Argentina to eastern Brazil, found in pastures, grasslands, wet montane forests, and second-growth riparian areas from sea level to 2300m elevation ^[1][2]
• Colony Type: Multi-queen colonies with documented colonies containing approximately 10 queens and 1,500 workers ^[3][4]
  • Colony: Polygyne
• Size & Growth:
  • Queen: MML 1.55-2.38mm ^[1]
  • Worker: 2.5-4mm (HL 0.50-0.84mm) ^[1]
  • Colony: Up to 3,000+ workers in established colonies ^[3]
  • Growth: Moderate
  • Development: Approximately 6-8 weeks (estimated from related Linepithema species) (Eggs: 0.22-0.40mm, three larval instars, pupae develop without cocoons ^[5])
• Antkeeping:
  • Temperature: Keep around 20-26°C. Foraging activity is positively correlated with temperature, with peak activity in warmer months (November-February) and reduced activity during cooler months ^[6][4]
  • Humidity: Moderate humidity preferred. Colonies avoid desiccation risk, foraging activity decreases during hot, dry afternoon hours and increases with higher humidity ^[6][4]
  • Diapause: Partial winter slowdown. Foraging activity reduces significantly from July through September but continues year-round. Colonies remain active but with reduced activity during Southern Hemisphere winter (June-August) ^[6][7]
  • Nesting: Subterranean nesters. In captivity, use test tubes or formicaria with moist soil substrate. Provide a moisture gradient so ants can self-regulate. They nest under stones, in rotting wood, and sandy soil in the wild ^[1][2]
• Behavior: Generally non-aggressive toward humans but competitive with other ant species. Workers are small and quick-moving, foragers primarily active from dusk through morning. They show seasonal shifts in food preference, protein-heavy in winter/spring, carbohydrate-heavy in autumn. Colonies are polydomous (multiple nest sites) and highly adaptable to different habitats. Escape risk is moderate due to small size, use standard barrier methods ^[6][4]
• Common Issues: small size means escapes are possible without fine mesh barriers, colonies may decline if humidity drops too low, they avoid desiccation, wild-caught colonies may carry parasites from vineyards, multi-queen colonies can be difficult to establish if queens fight during founding, foraging stops during hottest afternoon hours, don't mistake this for illness

Housing and Nest Setup

Linepithema micans is a ground-nesting ant that prefers moist soil environments. In captivity, standard test tubes work well for founding colonies, while larger colonies do well in formicaria with soil or plaster nests. Provide a water reservoir connected to the nest chamber to maintain humidity, these ants are sensitive to desiccation and will avoid dry areas. Create a humidity gradient by keeping one end moister than the other, allowing the colony to self-regulate. The outworld should be simple and easy to clean, as these ants are small and can be lost in elaborate setups. Use a test tube bridge or simple foraging area connected to the nest. Because of their small size, ensure all connections are snug, gaps as small as 1mm can allow escapes. ^[1][2][7]

Feeding and Diet

Like their relatives the Argentine ants, Linepithema micans are generalist feeders with interesting seasonal preferences. In captivity, offer both protein and carbohydrate sources. Protein foods like small insects (fruit flies, pinhead crickets, mealworm pieces) should be offered more frequently during winter and spring months. Carbohydrate sources like sugar water, honey, or inverted sugar solutions are preferred in autumn. Keep a constant supply of sugar water or honey, and offer protein 2-3 times per week. In the wild, they heavily associate with sap-sucking insects for honeydew, so they readily accept sweet liquids. Their small size means even tiny prey items are appreciated, they cannot take down large insects. Remove uneaten protein within 24-48 hours to prevent mold. ^[6][4]

Temperature and Seasonal Care

Maintain temperatures between 20-26°C for optimal colony health. These ants are native to temperate and subtropical South America and tolerate a range of conditions. Foraging activity correlates strongly with temperature, they become most active in the warmest months (November-February in the Southern Hemisphere) and reduce activity during winter. During the cooler months (June-August), expect reduced foraging and more time spent in the nest. They do not require true hibernation but will slow down significantly when temperatures drop. Room temperature (around 20-24°C) is typically suitable. Avoid temperatures above 30°C as this causes stress and increased mortality. Heating cables can be used on one side of the nest to create a temperature gradient, but always provide unheated areas so ants can escape excess heat. ^[6][4][7]

Foraging Patterns and Activity

Understanding their activity patterns helps with feeding schedules. Workers are primarily nocturnal/diurnal crepuscular, most active at dusk and dawn, with peaks in the morning hours. Activity drops significantly during the hottest and driest hours of afternoon. This is an adaptation to avoid desiccation, as their small body size makes them vulnerable to drying out. In captivity, you'll notice most foraging activity happens in the evening and morning hours. During winter months (June-August in their range), foraging shifts more to nighttime. This natural rhythm means you should time protein feeding to coincide with their active periods, offering food in the evening typically yields better results than morning feedings. ^[6][4]

Colony Structure and Multi-Queen Care

Linepithema micans is polygynous, meaning colonies naturally have multiple queens. Research shows colonies can contain around 10 queens and 1,500-3,000 workers ^[3][4]. Unlike single-queen species, these colonies don't have the same territorial aggression between founding queens. When keeping this species, you may receive colonies with multiple queens, this is normal and they typically coexist peacefully. The presence of multiple egg-laying queens contributes to faster colony growth once established. However, this also means colonies can become quite large, so plan for an expanding setup. Queens are not aggressive toward each other in established colonies, but when introducing new queens to an existing colony, monitor for initial aggression.

Common Problems and Solutions

The most common issues with Linepithema micans in captivity relate to their small size and humidity requirements. Escape prevention is important, these tiny ants can squeeze through surprisingly small gaps. Use fine mesh on any ventilation and ensure all connections are tight. Humidity management is critical, too dry and colonies will decline, with workers becoming sluggish. Too wet can lead to mold. Aim for consistently moist (not waterlogged) nest material. Another issue is overfeeding, their small size means they can't consume large prey items. Remove uneaten food promptly. Finally, if collecting from the wild in vineyard areas, be aware these ants may carry parasites or be associated with the harmful vine scale insect, quarantine new colonies before introducing to established setups. ^[6]

Frequently Asked Questions

References