Meranoplus

Classification

Meranoplus is a unique and charismatic myrmicine genus of hairy, slow-moving, and armored ants. The genus was previously classified in its own tribe, the Meranoplini, with one fossil genus, Parameranoplus, from Baltic amber (44.1 ± 1.1 mya), but was moved to Crematogastrini by Ward et al. (2015). The historic shuffling of Meranoplus through higher taxa — Cryptoceridae, Cataulacinae, Tetramoriini, Meranoplini — reflects our poor understanding of the phylogenetic position of Meranoplus within the Formicidae. Brady et al. (2006) recovered a clade of Meranoplus and Cataulacus, although this relationship was not supported in Moreau et al. (2006).

Distribution

The extant species of Meranoplus are distributed throughout the Old World, absent only from the Palearctic and Oceania regions but with the exception of M. levellei, from New Caledonia.

Biology

Species of this genus are predominantly ground-nesting and, when disturbed, will display thanatosis enhanced by crypsis, i.e., individuals will accumulate dirt in their pilosity and play dead. With respect to diet, most species are omnivores and facultative granivores, while others, including the whole M. diversus species group, are specialist granivores. At least one species, the Malaysian rainforest-dwelling M. mucronatus is known to have a trophobiotic relationship with hemipterans. Meranoplus species are known to be active both day and night, and to recruit via pheromone trails laid from the base of the sting using secretions from their extremely large Dufour glands. The function of the spatulate sting is still unknown. The only species of Meranoplus for which mating has been reported is M. peringuiyi, in which mating swarms occurred after a rain and where males patrolled for the outnumbered females in a zig-zag manner.