Myrmica incompleta

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Cold climates across Canada and the northern United States, from the Maritime Provinces west to Alaska, with a southern extension down the Rocky Mountains to New Mexico. Found in moist, open or semi-open habitats including bog edges, fens, wet meadows, and deciduous forests ^[3][4].
• Colony Type: Polygynous (multi-queen) colonies with monomorphic workers. Colonies can become very large and sometimes appear unicolonial over wide areas. Polydomous – nests spread across multiple connected locations ^[3][8][4].
• Size & Growth:
  • Queen: Size data unavailable – inferred from Myrmica genus (~5–7 mm)
  • Worker: 3.5–5.0 mm ^[1]
  • Colony: Very large colonies possible, polygynous colonies can develop large populations ^[3][4]
  • Growth: Moderate (estimated based on typical Myrmica development)
  • Development: 6–10 weeks at optimal temperature (estimated from related Myrmica species) (Exact timeline for this species is not confirmed in the literature.)
• Antkeeping:
  • Temperature: Keep cool, around 18–22°C. Avoid temperatures above 25°C, which can be fatal. This cold-climate species does best at room temperature or slightly cooler ^[3][4].
  • Humidity: Requires high humidity – keep the nest substrate consistently damp but not waterlogged. In nature they inhabit bogs and wet meadows, so moisture is critical ^[3][2].
  • Diapause: Yes – requires winter hibernation. Provide a 3–4 month cold period at 5–10°C to simulate winter conditions ^[3].
  • Nesting: Natural nests are built in moist soil, under stones, and in moss hummocks. In captivity, use test tubes with a water reservoir, plaster nests, or Y‑tong formicaria. Keep the nest material consistently moist ^[3][2].
• Behavior: Workers are generally sluggish and non-aggressive, but they can sting if handled ^[5]. They are cold-climate specialists that remain active at cooler temperatures. Escape risk is moderate – standard containment is sufficient for this size of ant (3.5–5 mm) ^[3].
• Common Issues: overheating – temperatures above 25°C can kill the colony, so keep the nest in a cool spot, low humidity – colonies may fail if the substrate dries out, check moisture levels regularly, hibernation failure – a proper cold period is essential, without it colonies weaken and die, large polygynous colonies can become difficult to manage – plan for expansion in advance, wild‑caught colonies may carry the social parasite Formicoxenus provancheri

Housing and Nest Setup

Myrmica incompleta does well in test tube setups or plaster nests that retain moisture. Since they naturally nest in moist soil and moss ^[3][2], keep the nest material consistently damp but not waterlogged. A test tube with a water reservoir works well – fill about one‑third with water, stuff cotton to create a chamber, and place your queen or colony inside. Cover the tube with a dark cloth for the first week to reduce stress. For larger colonies, a Y‑tong or plaster formicarium with a water chamber maintains humidity. Avoid acrylic nests, natural materials are better. Simple setups are fine as long as moisture levels are maintained.

Feeding and Diet

In the wild, Myrmica incompleta feeds heavily on honeydew from root‑feeding aphids and coccids, and also scavenges small insects ^[7][2]. In captivity, offer sugar water or honey as a constant energy source, and provide protein (small crickets, mealworms, or fruit flies) twice a week. They associate with over 20 aphid species, so they have a broad diet ^[7]. Drop food directly into the outworld or near the nest entrance. Remove uneaten protein within 24–48 hours to prevent mold.

Temperature and Seasonal Care

This is a cold‑climate species – keep temperatures between 18–22°C ^[3][4]. They can tolerate cooler conditions better than heat, avoid temperatures above 25°C. During winter, they require a true diapause (hibernation) of 3–4 months at 5–10°C. To hibernate, move the colony to an unheated garage or refrigerator (not freezer) from late fall through early spring. Gradually warm them back up in spring. Failure to provide proper hibernation often leads to colony decline.

Colony Structure and Growth

Myrmica incompleta forms polygynous colonies with multiple reproductive queens working together ^[3][8]. Colonies can become very large, sometimes appearing unicolonial over large areas. Workers are monomorphic (all similar in size), though this species shows more size variation than typical Myrmica ^[3]. Growth is moderate – expect 6–10 weeks from egg to first worker at optimal temperature. Once established, colonies grow steadily and can reach thousands of workers ^[3][4]. The presence of multiple queens makes colonies resilient to queen loss, but do not combine unrelated colonies as they may not integrate peacefully.

Frequently Asked Questions

Report an Issue

The current care sheet is based fully on literature. See inconsistencies, or something that's incorrect? Please report here, it will be resolved after review from an admin. Contributing to the blogs tab also helps providing information, to make us be able to further improve the caresheets. Thank you for your support!

References