Melissotarsus emeryi - "Bee-legged boring ant"
Melissotarsus emeryi is a fascinating and highly specialized ant species from the Afrotropical and Malagasy regions, known for its cryptic lifestyle. These ants are small, typically yellowish-brown, with workers ranging from 2.75 to 3.5 mm. They possess a unique morphology, including flattened, six-segmented antennae with a strong two-segmented club, and remarkably adapted legs. Their middle and hind coxae are greatly enlarged, as are the hind femurs, giving them a 'bee-legged' appearance. Uniquely, their second pair of legs projects upward, an adaptation for bracing themselves against tunnel roofs while chewing through live wood. This unusual leg structure means workers cannot walk normally on flat surfaces and are almost exclusively confined to their arboreal nests. A defining characteristic is the ability of adult workers to produce silk from glands in their heads, which they use to line their tunnels and seal cracks, a trait uncommon among adult ants. Their mandibles are also strongly adapted for wood-boring. Colonies live in obligate mutualism with armored scale insects (Diaspididae), which they keep within their chewed galleries for sustenance, as these scale insects provide proteins and wax rather than honeydew.
- Difficulty: Expert
- Origin & Habitat: Africa and Madagascar (Afrotropical and Malagasy regions), specifically recorded in countries like Ethiopia, Kenya, Tanzania, South Africa (Western and Northern Cape, KwaZulu-Natal, Mpumalanga), Zimbabwe, Mozambique, Ghana, Cameroon, and Namibia. in Arboreal; they tunnel and nest in the healthy wood of living trees and shrubs, beneath the bark. Host trees belong to over 20 families..
- Colony Type: Polygyne (multiple queens), claustral (queens establish colonies in isolation but need to acquire scale insect crawlers during founding) founding.
- Size & Growth:
- Queen: Not specified
- Worker: 2.5-3.5mm
- Colony: Large (tens of thousands, potentially up to 43,000 individuals including larvae). Medium to Fast, considering large colony sizes reported and year-round sexual production in some related species. growth.
- Antkeeping:
- Temperature: Specific temperature ranges are not widely documented for direct antkeeping, but given their natural habitat in African and Malagasy regions, a stable warm environment is implied. Temperatures around 24-28°C might be suitable, mimicking tropical to subtropical conditions..
- Humidity: High humidity is likely crucial due to their cryptic, wood-dwelling lifestyle. Maintaining high ambient humidity, especially within the nest material, would be important to prevent desiccation and support their symbiotic scale insects. During the day, their activity has been positively correlated with relative humidity..
- Diapause: Not required. Not specified at Not specified.
- Nesting: Requires a setup that simulates living wood, such as a specialized formicarium made from or containing live wood sections, or a material that can be chewed into intricate galleries. Given their reliance on symbiotic armored scale insects, the chosen nesting material must be able to host and sustain these scale insects..
- Behavior: Low (towards handler, as they are rarely outside the nest; however, workers are vulnerable to other ant species) aggressiveness.
- Common Issues: Maintaining host scale insect colony, Providing suitable living wood for tunneling, Humidity fluctuations, Fungal growth within nest (despite silk lining, if conditions are poor), Invasion by other ant species if nest is compromised, Obtaining and sustaining a viable symbiotic relationship.
Keeping Melissotarsus emeryi is an endeavor for truly dedicated antkeepers due to their unique and highly specialized lifestyle. These ants are absolute homebodies, rarely if ever venturing out of their tree tunnels, except for nuptial flights. This means a standard outworld setup is essentially useless for them. The entire colony, including their food source-armored scale insects-must be housed within the nesting material itself. Successful long-term keeping would necessitate a deep understanding of their mutualistic relationship with Diaspididae scale insects and the ability to cultivate these specific scale insects within the ants' living wood environment. It's not just about providing a nest; it's about providing an entire self-sustaining micro-ecosystem.
One of the most remarkable adaptations of Melissotarsus emeryi workers is their silk production. Unlike most ants where only larvae spin silk, adult workers of this genus can produce silk from glands in their heads. They use this silk, combined with chewed wood particles, to reinforce their tunnels and seal off any breaches, offering protection from invaders and potentially regulating humidity and fungal growth within the nest. This is a crucial aspect of their nest integrity and health, and any captive setup would need to account for this behavior, perhaps by providing chewable wood that encourages silk-spinning activity.
The feeding habits of Melissotarsus emeryi are truly unique among ant species. They don't collect honeydew, a common food source for many ant-scale insect mutualisms. Instead, they appear to consume the wax and protein secretions that Diaspididae scale insects typically use to build their protective shields. Inside the ant nests, these scale insects are often found 'naked' without their shields, benefiting from the ants' protection while providing direct nutritional benefits to the colony. Some research even suggests the possibility of the ants 'culling' scale insects for consumption, implying a form of ant husbandry. This complex nutritional relationship presents a significant challenge for antkeepers, requiring a viable and sustainable population of their specific symbiotic scale insect partners.
Their peculiar leg morphology, with the middle pair projecting upwards, is an extreme adaptation for tunnelling through living wood. This makes them highly inefficient, almost incapable, of walking on flat, open surfaces. If workers are ever exposed outside their tunnels, they quickly fall over and struggle to right themselves. This further emphasizes their absolute reliance on their intricate network of tunnels within the wood and highlights why an open outworld for foraging is entirely inappropriate for this species. Any necessary observation or intervention would need to be done with extreme care to prevent workers from being exposed to flat, untextured surfaces.
