Crematogaster acuta

Crematogaster acuta

Crematogaster acuta is a medium-sized ant known for its distinctive defensive behavior, when disturbed, workers emerge in large numbers, raise their abdomens in the air, and secrete a white frothy substance. Workers measure 0.86-0.98mm in head length and feature long, pointed propodeal spines and an acute ventral tooth on the postpetiole. Their coloration ranges from dark red-brown to black, and they have abundant long whitish setae on the face and body. This species ranges from Mexico through Central America into southern Brazil and Bolivia, making it one of the most widespread Crematogaster species in the Neotropics ^[1][2].

These ants are adapted to open, disturbed habitats and are commonly found along roadside vegetation, pasture edges, and young second-growth forests. They nest in dead wood, including hollow stems, fence posts, and the dead cores of living trees, and form large polydomous colonies that spread across multiple nest chambers. A particularly interesting trait is their association with active termite nests (Nasutitermes), where they establish colonies in the external galleries while the termites occupy internal spaces. This may represent a mutual defensive relationship ^[3]. Queens display morphological features sometimes associated with social parasitism, though the species is not confirmed as parasitic ^[1].

Quick Summary

• Difficulty: Medium
• Origin & Habitat: Neotropical region, Mexico to southern Brazil, Bolivia, and Paraguay. Found in open disturbed habitats like roadside vegetation, pasture edges, and young second-growth forest. Occurs in both wet and seasonally dry climates, typically below 500m elevation but recorded up to 1000m in Bolivia ^[1][2][4].
• Colony Type: Polydomous, colonies nest in multiple connected locations within dead wood. Colony size is very large but not high density. Exact queen count (single or multiple) is unconfirmed from research ^[1].
• Size & Growth:
  • Queen: 1.18-1.30mm head length ^[2]
  • Worker: 0.86-0.98mm head length ^[1][2]
  • Colony: Very large colonies, exact numbers not specified in research ^[1]
  • Growth: Moderate, inferred from typical Myrmicinae development patterns
  • Development: 6-10 weeks, estimate based on typical Crematogaster development at tropical temperatures (Development time not directly studied for this species. Tropical temperature range (24-28°C) likely supports faster development)
• Antkeeping:
  • Temperature: Keep at 24-28°C. As a tropical species, they prefer warmth. A heating cable on one side of the nest creates a suitable gradient. Avoid temperatures below 20°C as this species is adapted to lowland tropical conditions ^[2].
  • Humidity: Moderate to high, aim for 60-80% relative humidity. Their natural habitat includes both wet and seasonally dry forests, so they tolerate some variation. Keep the nest substrate moist but not waterlogged, with some drier areas available.
  • Diapause: No, this is a tropical species that does not experience cold winters. They remain active year-round in captivity ^[1].
  • Nesting: Provide dead wood or wood-based nesting material. In captivity, a wooden formicarium, Y-tong nest, or plaster nest with wood inclusions works well. They naturally nest in dead wood, hollow stems, and fence posts. Multiple connected chambers allow for their polydomous colony structure ^[1].
• Behavior: Workers are defensive but rarely bite. When threatened, they emerge in large numbers, raise their abdomens (the 'acrobat' behavior), and secrete a white frothy substance from the gaster tip. They are generalist foragers, active both day and night, and readily attracted to protein baits like tuna. Workers forage on the ground and in vegetation. Escape risk is moderate, use standard barrier methods but they are not particularly aggressive biters ^[1].
• Common Issues: colonies can be difficult to establish from founding queens due to unknown founding requirements, polydomous nature means they need more space than single-nest species, one chamber is not enough, larvae may be parasitized by Eulophidae wasps, wild-caught colonies can carry these parasites ^[5], tropical species will decline or die if kept too cool, maintain warmth year-round, queen morphology suggests possible social parasitism but this is unconfirmed, do not combine with other species

Nest Preferences and Housing

In the wild, Crematogaster acuta nests exclusively in dead wood, researchers have found colonies in dead Piper stems, fence posts, Cecropia branches, and the exposed dead core of living tree trunks. The colonies distribute workers evenly throughout the wood, filling spaces like a sponge rather than concentrating in large chambers ^[1]. For captive care, provide a wooden formicarium, Y-tong nest, or plaster nest with wood inclusions. The nest should have multiple connected chambers to accommodate their polydomous nature, a single small chamber will not suffice for established colonies. Ensure the wood or nest material remains moist but not saturated. These ants do well in naturalistic setups with dead wood pieces as the primary nesting material.

Feeding and Diet

Crematogaster acuta is a generalist forager that exploits various food sources. In the wild, workers have been observed foraging on the ground and in vegetation, and they are strongly attracted to protein baits like tuna and sardines ^[2]. They also tend hemipteran (aphid-scale) insects for honeydew, researchers observed them interacting with Toxoptera aurantii on cocoa trees and with Coccus viridis on coffee plants ^[5][6]. In captivity, offer protein sources like mealworms, crickets, or other small insects 2-3 times per week. Sugar water or honey can be offered occasionally, though they are primarily protein-focused foragers. Remove uneaten prey after 24-48 hours to prevent mold.

Temperature and Seasonal Care

As a tropical species from the Neotropics, Crematogaster acuta requires warm conditions year-round. They occur in both wet and seasonally dry climates, typically below 500m elevation but have been recorded up to 1000m in Bolivia ^[1][2]. Keep the nest area at 24-28°C, this matches their natural lowland tropical habitat. A heating cable placed on one side of the nest creates a temperature gradient that allows workers to self-regulate. Avoid temperatures below 20°C, as prolonged cool conditions will stress or kill colonies. Unlike temperate species, they do not require hibernation or diapause, maintain consistent warmth throughout the year.

Defense and Behavior

This species is famous for its distinctive defensive display. When nests are disturbed, workers emerge in great numbers, wave their gasters in the air (the 'acrobat' behavior that gives the genus its name), and exude copious quantities of a white frothy material from the tip of the gaster ^[1]. Despite this dramatic display, they rarely bite, the frothy secretion is their primary defense. Workers are active both day and night, and they forage individually rather than in large raiding parties. In captivity, this means you will see regular foraging activity but not aggressive swarming unless the nest is directly threatened. Their generalist foraging style makes them adaptable to various feeding schedules.

Colony Structure and Growth

Crematogaster acuta forms polydomous colonies, meaning the colony spreads across multiple nest sites rather than concentrating in one location. Researchers have observed colonies occupying dead wood with workers distributed evenly throughout, suggesting the colony expands as needed into available spaces ^[1]. The species produces very large colonies but they are not frequently encountered, indicating lower colony density compared to some other Crematogaster. Queens exhibit morphological features sometimes associated with social parasitism (like reduced size or specialized queen traits), but this species is not confirmed as actually parasitic. Growth rate is moderate, expect 6-10 weeks from egg to first worker at optimal tropical temperatures, though this is estimated from genus patterns rather than directly studied.

Frequently Asked Questions

References