Neivamyrmex pertii - "Perty's Army Ant"
Stepping into the fascinating world of army ants, we encounter Neivamyrmex pertii, an incredibly dynamic species within the Dorylinae subfamily. These captivating ants are renowned for their truly nomadic lifestyle, completely abandoning the concept of a fixed nest. Instead, their entire colony-queen, workers, and precious brood-forms temporary living shelters, or bivouacs, constantly on the move in relentless pursuit of food resources. The workers, while varying in size from small to medium, display a subtle polymorphism, working in perfect concert. Their unique ergatoid queen, being wingless, is noticeably larger than her worker caste, while the winged males, often spotted near lights, can also be quite substantial. A key identifier for these dedicated foragers is their distinctive 12-segmented antennae and simple, un-toothed claws on their worker legs.
- Difficulty: Expert
- Origin & Habitat: Neotropical Region (Argentina, Bolivia, Brazil, Chile, Paraguay, Uruguay) in Primarily subterranean environments, including forests and grasslands, occasionally foraging above ground at night or on cloudy days. They thrive in warm, humid conditions..
- Colony Type: Monogyne (typically one queen per new colony, though the genus has exceptions), semi-claustral (new colonies are founded by a queen leaving with a portion of the workers from the parent colony; queens are wingless and do not perform nuptial flights) founding.
- Size & Growth:
- Queen: 10-15mm
- Worker: 2-7mm
- Colony: Large (tens of thousands to hundreds of thousands of workers). Fast growth.
- Antkeeping:
- Temperature: Maintain a stable temperature between 24-28°C (75-82°F). Consistency is key to supporting their active nomadic cycles..
- Humidity: High humidity is crucial, ideally ranging from 70-90% in their bivouac area, with a slight gradient for the foraging area..
- Diapause: Not required. Not specified at Not specified.
- Nesting: Due to their nomadic behavior, Neivamyrmex pertii do not use traditional nests. They require a specialized setup that allows for regular colony migration and the formation of temporary bivouacs. This often involves a 'trail' system connecting expandable chambers or foraging areas that can be regularly changed or expanded to simulate their natural movements. A dark, escape-proof, and humid bivouac chamber is essential..
- Behavior: High (towards other ants, as they are predatory) aggressiveness.
- Common Issues: Difficulty providing consistent live ant brood, Managing nomadic and statary cycles, Escape artists due to their constant movement, Maintaining high and stable humidity levels in a dynamic setup, Stress or death due to inadequate housing or diet.
Embarking on the journey of keeping Neivamyrmex pertii is a true testament to an antkeeper's dedication, placing them squarely in the 'expert' category. These remarkable army ants operate on a strict nomadic cycle, alternating between a 'nomadic phase' where the entire colony relocates nightly, and a 'statary phase' where they settle in a temporary bivouac for a few weeks to allow the queen to lay eggs and for the brood to develop. Replicating this intricate rhythm in captivity demands highly specialized formicaria designs, often involving interconnected modules or expandable outworlds that facilitate regular colony migrations and the creation of new, secure bivouac sites.
The dietary requirements of Neivamyrmex pertii are perhaps their most defining, and challenging, characteristic. As obligate predators, their sustenance comes almost exclusively from the larvae and pupae of other ant species. This means a consistent and varied supply of live ant brood is an absolute necessity to maintain a thriving colony in your setup. Unlike many other ant species that happily consume a range of insect proteins and sugar solutions, these army ants demand a specialized diet, making the logistical challenge of sourcing sufficient quantities of diverse prey ant offspring a primary concern for any aspiring Neivamyrmex keeper.
Reflecting their natural tendencies, Neivamyrmex pertii predominantly live a subterranean life. Most of their foraging expeditions and bivouac formations occur deep underground. While you might occasionally observe them in raiding columns above ground during the cooler hours of the night or on overcast days, their true nature is to operate beneath the surface. For observation in a captive ant setup, it's highly recommended to use red light, as this spectrum is less disruptive to their behavior, allowing you to witness their fascinating collective actions without causing undue stress.
A unique aspect of Neivamyrmex pertii colony dynamics centers around their queen and male alates. Unlike most ant species where queens embark on a nuptial flight, Neivamyrmex pertii queens are ergatoid, meaning they are wingless and stay with the colony. New colonies are founded not by a queen flying off to a new location, but through 'colony budding' or 'fission', where a section of the mature colony, along with a daughter queen, branches off to establish a new foraging unit. Conversely, the males of this species are fully winged and are often seen flying, particularly attracted to light sources, which is how they are sometimes inadvertently encountered by people.
