Acromyrmex
Acromyrmex lundi
Care Guide
Acromyrmex lundi is a classic leafcutter ant species native to South America, known for its intricate fungus‑farming lifestyle and pronounced size polymorphism. The queen measures between 12 and 14 mm, while workers range from just 2 mm in the smallest minims up to 10 mm in the larger foragers and defenders. Like all Attini, these ants do not eat the leaves they cut; instead, they process fresh vegetation into a substrate on which they cultivate a specialised fungus – their sole colony food source. This symbiotic relationship makes them one of the most fascinating ants to keep, though it also places them firmly in the advanced category.
Care difficulty
Keeping Acromyrmex lundi is an advanced undertaking, requiring a dedicated keeper who understands the constant demands of a fungus‑feeding colony. Unlike seed‑eating species, leafcutters need a steady supply of fresh, untreated leaves (bramble, rose, or oak are reliable choices) as well as supplemental insect protein and a bit of fruit or oats for the fungus. The fungus garden itself must be kept clean; waste and old leaves must be removed regularly to prevent mould and mites. Temperature should stay between 24 and 28 °C, and humidity must be maintained at 60–80 %, with the fungus chamber kept noticeably moist but not waterlogged. These ants do not require hibernation and will remain active year‑round. Because of their large colony size (10,000 to 50,000 workers) and the need for a large, well‑ventilated formicarium with a separate foraging area, this species is best suited for experienced keepers with some space and time to dedicate.
Housing
A successful Acromyrmex lundi setup requires a nest that offers stable high humidity and good ventilation. Many keepers use a combination of a plaster or clay nest for the fungus garden connected to a larger outworld for leaf foraging. The fungus chamber should be kept dark and undisturbed, with a slightly higher humidity than the rest of the nest. A drainage layer or a water reservoir in the nest is helpful, as the fungus needs constant moisture but must not sit in standing water. Provide a garbage chamber or separate waste area – leafcutters are meticulous about removing spent substrate. The outworld should have a leaf‑cutting area where you can place fresh leaves, and a water source with low surface tension (cotton‑plugged test tube or water dispenser) to prevent drowning. Because the colony can become very populous over time, plan for expansion; modular systems work well.
First days after purchase
When your Acromyrmex lundi colony arrives, give it time to settle. Place the formicarium in a quiet, dimly lit room with stable temperature and minimal vibration. The queen and her initial workers will be stressed from shipping; avoid disturbing them for at least 48 hours. Ensure the fungus garden is visibly moist – if it looks dry, add a few drops of water near its edges (never directly on the fungus). Offer a small piece of fresh leaf (e.g., bramble) and a drop of diluted honey or sugar water to support the workers. Do not open the nest unless absolutely necessary; observe through the glass or acrylic. Over the first week, watch that workers begin exploring and cutting leaf pieces – this signals the colony has acclimated. Once you see fresh green fragments being carried into the fungus chamber, you can gradually increase the leaf supply and begin regular feeding. Patience is key – a successful leafcutter colony starts with a calm, undisturbed founding phase.
