Nesomyrmex anduzei

Nesomyrmex anduzei

Nesomyrmex anduzei is a small Neotropical ant belonging to the Myrmicinae subfamily. Workers are part of the larger Nesomyrmex species, measuring with a Weber's length (WL) of 1.4mm or more ^[1]. They can be identified by their dentate (toothed) humeri, rounded mesonotum without lateral projections, and antennae with 12 segments. The antennal scape extends past the posterior margin of the head when pulled back ^[1]. These ants are primarily arboreal, living in the canopy of tropical rainforests across their range.

Originally described from Venezuela in 1943 from specimens collected in a cave near Puerto Cabello, this species has since been recorded across the Neotropical region including Brazil, Colombia, Costa Rica, French Guiana, Guyana, Suriname, Venezuela, Ecuador, and Peru ^[1][2]. Ecuadorian specimens were captured by hand on wooden docks at Limoncocha lagoon and through canopy fogging in Amazon lowland rainforest, indicating they nest in elevated arboreal locations and sometimes forage at ground level near water ^[1].

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Neotropical region spanning from Central America (Costa Rica) through South America (Colombia, Venezuela, Guianas, Brazil, Peru, Ecuador). Found in Amazon lowland rainforest and associated with wooden structures near water. Arboreal nesting species ^[1][3].
• Colony Type: Colony structure is unconfirmed. No data available on whether they are single-queen (monogyne) or multi-queen (polygyne) colonies.
• Size & Growth:
  • Queen: Undocumented, queen has not been described in detail ^[2]
  • Worker: Weber's length (WL) ≥1.4mm, making them one of the larger Nesomyrmex species ^[1]. Mean mass
  • Colony: Unknown, no colony size data available
  • Growth: Unknown, no development data available
  • Development: Unconfirmed, no direct development studies. Based on typical Myrmicinae patterns from tropical regions, estimate 4-8 weeks at optimal temperature. (Development timeline is unconfirmed. Related Nesomyrmex species suggest relatively standard Myrmicinae development.)
• Antkeeping:
  • Temperature: Tropical species, keep at 24-28°C. Provide a gentle temperature gradient allowing workers to self-regulate. Room temperature in most homes may be suitable if kept in the warmer range.
  • Humidity: High humidity required, these are rainforest ants from the Amazon basin. Keep nest substrate consistently moist but not waterlogged. Provide humidity levels around 70-80% to match their natural canopy environment.
  • Diapause: No, as a tropical species, they do not require hibernation. Maintain consistent warm temperatures year-round.
  • Nesting: Arboreal species, they naturally nest in elevated locations, tree hollows, and under bark. In captivity, Y-tong (AAC) nests or plaster nests with narrow chambers work well. They may also accept test tube setups if provided with elevated positions. Avoid deep soil nests, they prefer enclosed spaces.
• Behavior: Arboreal and relatively active foragers. Workers are small (
• Common Issues: escape prevention is critical due to their very small size, use fine mesh barriers and tight-fitting lids, high humidity requirements can lead to mold if ventilation is poor, tropical species may decline if temperatures drop below 24°C, lack of documented colony founding information makes initial establishment challenging, arboreal nature means they may not accept deep soil test tube setups readily

Natural History and Distribution

Nesomyrmex anduzei is a Neotropical ant species with a broad distribution across Central and South America. Originally described from Venezuela in 1943,their range extends from Costa Rica through Colombia, Venezuela, the Guianas, Brazil, Peru, and most recently documented in Ecuador ^[1]. The species was first discovered in a cave near Puerto Cabello, Venezuela, which initially led to its classification as a troglóxeno (cave-dwelling) species, though subsequent findings confirm they are primarily arboreal rainforest ants ^[4].

In Ecuador, specimens have been collected from the Amazon lowland rainforest at elevations around 220-250 meters. They were captured both by hand on wooden docks at Limoncocha lagoon and through canopy fogging techniques, demonstrating they forage at various heights within the forest structure ^[1]. The 'Colombian variety' morphotype found in Ecuador differs slightly from the typical description in having a more uniformly colored body and different sculpture patterns on the mesosomal dorsum, though these differences were not considered sufficient for species separation ^[1].

Identification and Morphology

Nesomyrmex anduzei belongs to the larger species group within the genus Nesomyrmex, characterized by a Weber's length (WL) of 1.4mm or greater ^[1]. Workers can be identified by several key diagnostic characters: the humeri (shoulder area) are strongly angled and serrated, the mesonotum is rounded or has blunt edges without the triangular lateral projections seen in some relatives, the antennal scape extends past the posterior margin of the head when pulled back, and the antenna has 12 antennomeres (antennal segments) ^[1].

They are morphologically similar to Nesomyrmex pulcher and Nesomyrmex sculptiventris but can be distinguished by their strongly angled and serrated humeri, mesonotum without lateral projections, and obovoid (egg-shaped) petiole ^[1]. Workers are very small, with a mean mass of less than 1mg, making them among the smaller ants in the Myrmicinae subfamily despite their relatively large WL measurement ^[5].

Housing and Nest Preferences

As an arboreal species, Nesomyrmex anduzei prefers elevated nesting locations. In captivity, they do well in Y-tong (acrylic) nests or plaster nests with chambers scaled to their tiny size. The chambers should be relatively narrow and enclosed, mimicking the tree hollows and under-bark locations they use in nature. Test tube setups can work but may need to be positioned at an elevated angle or combined with other nest types to encourage acceptance.

The key requirement is maintaining high humidity while providing adequate ventilation to prevent mold. Use a moisture source that can be monitored, either a water reservoir in the nest setup or regular misting of the substrate. Since they are arboreal, avoid deep soil setups which they may not readily accept. Instead, provide them with enclosed spaces that retain humidity well. ^[1][3]

Temperature and Humidity Requirements

Being a tropical species from the Amazon basin, Nesomyrmex anduzei requires warm and humid conditions. Maintain temperatures between 24-28°C, with a gentle gradient allowing the colony to self-regulate. A heating cable on one side of the nest can help create this gradient, but ensure it does not dry out the nest too quickly.

Humidity should be kept high at approximately 70-80%. This can be achieved by keeping the nest substrate consistently moist but not waterlogged. Monitor for condensation on the nest walls, some condensation is good but excessive moisture can lead to mold problems. The combination of warmth and humidity is essential for brood development, which may stall or fail if conditions are too cool or dry.

Feeding and Diet

While specific dietary studies for Nesomyrmex anduzei are lacking, they are likely generalist omnivores like most Myrmicinae ants. In captivity, offer a varied diet including sugar sources (honey water, sugar water) and protein sources (small insects like fruit flies, pinhead crickets, or mealworms). As very small ants, prey items should be appropriately sized, tiny fruit flies and springtails are ideal.

Feed sugar water or honey regularly (every 2-3 days) and offer protein prey once or twice weekly. Remove any uneaten prey after 24 hours to prevent mold. Since they are arboreal foragers, they may prefer feeding stations positioned at elevated points within the outworld.

Behavior and Colony Care

Nesomyrmex anduzei workers are small and active foragers. They are not documented as particularly aggressive but will defend their nest if threatened. Their tiny size (under 1mg) means they can escape through remarkably small gaps, making escape prevention essential, use fine mesh barriers and ensure all connections are secure.

As an arboreal species, they may show more vertical activity than ground-nesting ants. Provide an outworld setup that allows for some climbing structure. They do not have documented swimming ability ^[5], so water features should be shallow if included. Colony founding and development details are unconfirmed, so new keepers should be prepared for a potentially slow establishment phase with careful attention to humidity and temperature stability.

Frequently Asked Questions

References