Neivamyrmex andrei

Neivamyrmex andrei

Neivamyrmex andrei is one of the most mysterious army ant species in North America, it is known only from the male caste, meaning we have never observed a queen or worker in this species ^[1]. Males are relatively large at 10-11mm, with distinctive broad front coxae that set them apart from most other US Neivamyrmex species (except N. swainsonii) ^[2]. The species ranges from Arizona and New Mexico south through western Mexico (Chihuahua, Colima, Nayarit, Sinaloa, Sonora, Veracruz, Jalisco) ^[3]. Males have been collected from late June through August, typically in forested areas with damp (mesic) conditions ^[4].

This species presents a unique challenge for antkeepers: it may actually represent the male form of Neivamyrmex agilis, and since no colony (queen + workers) has ever been documented, it cannot be kept in captivity ^[2]. This makes N. andrei more of a scientific curiosity than a viable keeping project.

Quick Summary

• Difficulty: Not Keepable
• Origin & Habitat: Arizona and New Mexico in the United States, extending south through western Mexico (Chihuahua, Colima, Nayarit, Sinaloa, Sonora, Veracruz, Jalisco). Found in forested areas, typically in damp (mesic) sites ^[2][3][4].
• Colony Type: Unknown, only the male caste has ever been documented. The species may represent the male of N. agilis, but no colony structure has been observed ^[2][1].
• Size & Growth:
  • Queen: Unknown, queens have never been described
  • Worker: Unknown, workers have never been described
  • Colony: Unknown, no colonies have been documented
  • Growth: Unknown
  • Development: Unknown, no colony data exists (This species is only known from males, no brood or colony development has ever been observed)
• Antkeeping:
  • Temperature: Unknown, no colony has been kept to determine requirements
  • Humidity: Unknown, no colony observations exist
  • Diapause: Unknown
  • Nesting: Unknown, no nesting behavior has been documented
• Behavior: Behavior is unstudied since only males have been collected. As an army ant, related Neivamyrmex species are nomadic predators that conduct raids, but specific behavior for N. andrei is unknown ^[4]. Escape risk cannot be assessed without worker observations.
• Common Issues: This species cannot be kept, only males are known to science, No queen or worker descriptions exist, making captive establishment impossible, The species identity is uncertain, may be males of N. agilis, No captive care research exists for this species

Why This Species Cannot Be Kept

Neivamyrmex andrei represents one of the most significant gaps in ant keeping knowledge. This species is only known from male specimens collected in the early 1900s, no queen or worker has ever been documented ^[1]. In the ant world, males are the reproductive caste that emerge from established colonies solely for mating flights. Without queens and workers, there is no way to establish a captive colony.

The situation is further complicated by the possibility that N. andrei may actually be the male caste of Neivamyrmex agilis ^[2]. If this is the case, then what we call N. andrei is simply the male form of an already-described species. Even if you could locate and identify N. andrei males, they would have no value in establishing a colony.

For antkeepers interested in army ants, consider keeping documented Neivamyrmex species where the full colony (queen, workers, brood) has been observed and described. Many army ant species are challenging to keep due to their nomadic nature and specific dietary needs, but at least their care requirements are known.

Distribution and Habitat

Neivamyrmex andrei is found across the southwestern United States and western Mexico. In the US, it has been recorded in Arizona (including the type locality at Nogales) and New Mexico ^[2]. In Mexico, it has been documented in Chihuahua, Colima, Nayarit, Sinaloa, Sonora, Veracruz, and Jalisco states ^[3].

The species appears to prefer forested habitats in damp (mesic) locations ^[4]. Males have been collected from late June through August, which likely represents the nuptial flight period ^[4]. The broad distribution across western Mexico suggests the species can handle a range of conditions, but without colony observations, we cannot determine what specific temperature and humidity preferences it might have.

Identification and Related Species

Male N. andrei can be identified by a distinctive feature: broad front coxae (the upper leg segments near where the legs attach to the body). In most US Neivamyrmex species, these are longer than broad, but N. andrei and the similar N. swainsonii have distinctly broader coxae ^[2].

Males measure 10-11mm in length, making them relatively large among US army ants. They have very large eyes and ocelli (simple eyes), a slender thorax, and distinctive genitalia. The body is reddish-brown with the head and thorax often darker, and wings are grayish with brownish-black veins ^[4].

The species was originally described as Neivamyrmex andrei by Emery in 1901,with Neivamyrmex oslari (described from an Arizona specimen) later synonymized under N. andrei ^[4].

Frequently Asked Questions

References