Lasiophanes picinus

Lasiophanes picinus

Lasiophanes picinus is a small to medium-sized ant native to southern South America, one of the southernmost ant species known to science. Workers are dark chestnut brown with lighter appendages, and they closely resemble the common Lasius niger but belong to a different genus within the Formicinae subfamily. This species inhabits the cool temperate forests of Patagonia and Tierra del Fuego, ranging from central Chile and Argentina down to the islands near Cape Horn at approximately 55°S latitude ^[1]. They are associated with Nothofagus forests and coniferous trees in their native range ^[2]. The colony structure and exact founding behavior of this species remain poorly documented in scientific literature.

Quick Summary

• Difficulty: Unknown, likely Medium to Hard due to limited availability and specific cold-climate requirements
• Origin & Habitat: Southern South America, Chile (Valparaíso to Magallanes) and Argentina (Neuquén to Santa Cruz), including Tierra del Fuego and Isla Navarino near Cape Horn. Inhabits Nothofagus forests and coniferous areas in western Patagonia and Tierra del Fuego ^[2][3].
• Colony Type: Colony structure is unconfirmed. Based on related Formicinae like Lasius, likely single-queen (monogyne) colonies, though this requires confirmation.
• Size & Growth:
  • Queen: Unconfirmed, no direct measurements available. Estimated 5-7mm based on genus-level patterns for related Formicinae.
  • Worker: Unconfirmed for workers. Males measured at 2.34-2.53mm ^[3]. Workers likely 3-5mm.
  • Colony: Unconfirmed. Based on similar temperate forest ants, likely several hundred workers at maturity.
  • Growth: Unknown, likely moderate, consistent with temperate climate species
  • Development: Unconfirmed. Based on related Lasius species, estimated 6-10 weeks at optimal temperature. (Development time is estimated from related temperate Formicinae species. Direct observations of this species are lacking.)
• Antkeeping:
  • Temperature: Keep cool, this is one of the southernmost ant species and requires cool conditions. Aim for 12-18°C, with room temperature (18-22°C) acceptable. Avoid overheating.]
  • Humidity: Moderate to high, forest-dwelling species. Keep nest substrate moist but not waterlogged. Provide a humidity gradient with a damp area and a drier area for choice.]
  • Diapause: Yes, based on temperate to cold Patagonian distribution, a winter dormancy period is likely required. Keep at 5-10°C for 2-3 months during winter.
  • Nesting: In nature they nest in forest floor soil and decaying wood. In captivity, a test tube setup works for founding colonies. For established colonies, a Y-tong or plaster nest with some moisture retention works well. Avoid dry, desert-style nests.]
• Behavior: Workers are likely generalist foragers, similar to related Lasius species. They probably collect honeydew from aphids and small insects. The species is not known to be aggressive. Escape risk is moderate, workers of typical size (3-5mm) can be contained with standard barriers, but fine mesh is recommended.
• Common Issues: limited availability, this species is rarely available in the antkeeping hobby, cold requirements may be difficult to maintain in warm climates without cooling, wild-caught colonies may not adapt well to captive conditions, specific humidity needs may lead to mold issues if overwatered, diapause requirements are not fully understood and may cause colony loss if not provided

Natural History and Distribution

Lasiophanes picinus is one of the most southerly distributed ant species in the world, found throughout Patagonia from central Chile and Argentina down to Tierra del Fuego and Isla Navarino near Cape Horn at approximately 55°S latitude ^[1]. This makes it one of the southernmost ant species known to science. The species was originally described from Chile by Julius Roger in 1863 and has been recorded throughout the Andes region from Valparaíso in central Chile to Magallanes in the far south ^[3]. In Argentina, they are found in Neuquén, Río Negro, Chubut, Santa Cruz, and La Pampa provinces ^[3]. They inhabit Nothofagus (southern beech) forests as well as areas with conifers like araucaria and cipreses de las guaitecas, and are also found near alerce and mañio trees in western Patagonia and Tierra del Fuego ^[2]. The climate in their range is cool temperate to subpolar, with cold winters and mild summers.

Appearance and Identification

Workers of Lasiophanes picinus are dark chestnut brown with lighter colored appendages, making them visually similar to the common Lasius niger but belonging to a different genus within the Formicinae subfamily ^[1]. Males have been described in detail, measuring 2.34-2.53mm in total length with very large compound eyes that occupy the lower half of the head sides and protrude from the lateral margins ^[3]. The antennae are 13-segmented with a very short scape approximately half the length of the third antennal segment. The head is subglobose in shape, and the body has short pilosity throughout. Workers would be expected to measure approximately 3-5mm, though exact worker measurements are not available in the literature. The species can be distinguished from similar Formicinae by the combination of its southern distribution, dark chestnut coloration, and the characteristic large eyes of the male caste.

Temperature and Seasonal Care

This species requires cool conditions unlike most commonly kept ants. Being one of the southernmost ant species on Earth, they have evolved to thrive in the cool temperate to subpolar climates of Patagonia and Tierra del Fuego ^[1]. Keep the nest area at 12-18°C year-round. Room temperature (18-22°C) may be acceptable but avoid temperatures above 22°C, as overheating can be fatal. During winter, provide a diapause period of 2-3 months at 5-10°C, simulating the harsh Patagonian winter. This species is poorly suited for warm climates without access to cooling. A thermoelectric cooler or placement in a cool basement may be necessary in warmer regions. Monitor colony behavior, if workers consistently avoid the heated areas of the nest, the temperature is too high. The cool requirement makes this species challenging for beginners or those in warm climates.

Nesting and Habitat Setup

In their natural habitat, Lasiophanes picinus nests in forest floor soil and decaying wood within Nothofagus forests and coniferous areas ^[2]. For captive care, use a test tube setup for founding colonies, a standard test tube with a water reservoir cotton-plugged at one end provides appropriate humidity. For established colonies, a Y-tong (acrylic) nest or plaster nest works well, as these materials can hold some moisture without becoming waterlogged. Avoid dry, desert-style formicaria. The nest should have a moisture gradient, some chambers damp, others drier, so the ants can self-regulate. Provide a shallow water dish in the outworld and occasional misting of the nest (only if it appears dry). Good ventilation is essential to prevent mold while maintaining humidity.

Feeding and Diet

Like other Formicinae, Lasiophanes picinus is likely a generalist omnivore. In nature, they probably forage for honeydew from aphids and scale insects, as well as small insects and nectar. In captivity, offer sugar water or honey water as a constant energy source. For protein, provide small insects like fruit flies, small crickets, or mealworms. Given their small to medium size, prey items should be appropriately sized. They likely accept a wide variety of foods similar to related Lasius species. Feed protein 2-3 times per week, and ensure sugar water is always available. Fresh water should also be accessible at all times.

Colony Establishment and Growth

The founding behavior of Lasiophanes picinus has not been directly documented, but based on its placement in the Formicinae subfamily, it likely follows the claustral pattern where the queen seals herself in a chamber and raises the first workers entirely on stored fat reserves without foraging. Expect the founding colony to remain sealed in for several weeks to months while the queen lays eggs and raises the first brood. Once workers emerge (nanitics), they will be small and should begin foraging. Growth rate is estimated as moderate, similar to related temperate ants. A mature colony likely reaches several hundred workers. Colonies appear to be single-queen based on related species patterns, though this requires confirmation. Patience is essential during the founding phase, as the colony establishes itself slowly.

Frequently Asked Questions

References