Myrmarachne

MacLeay, 1839

ant-mimic spiders, ant-mimicking jumping spiders

Myrmarachne is a large of -mimicking (Salticidae) first described by MacLeay in 1839. With approximately 188 described , it is the most diverse genus of jumping spider in Southeast Asia. These exhibit remarkable morphological and behavioral convergence with ants, including elongated with constricted waists, coloration matching local ant species, and foreleg waving to simulate . The genus has undergone significant taxonomic revision, with several genera split off in recent years including Helicius (2016) and the revalidation of Emertonius (2018).

Myrmarachne by (c) @dineshphotography7797, some rights reserved (CC BY), uploaded by @dineshphotography7797. Used under a CC-BY license.

Myrmarachne formicaria 92685782 by Zygy. Used under a CC0 license.

Myrmarachne formicaria 92685347 by Zygy. Used under a CC0 license.

Pronunciation

How to pronounce Myrmarachne: //mɪərˈmɑːrækniː//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Distinguished from other -mimicking by combination of elongated with distinct waist, relatively long projecting forward (especially in males), and foreleg waving to simulate ant . Males often have enlarged chelicerae that may lack glands. Coloration varies from black to depending on ant mimicked. Extremely similar to Bocus, which requires microscopic examination to distinguish.

Images

Distribution

Tropical and subtropical regions from Africa through Asia to Australia; highest diversity in Southeast Asia with approximately 80 described . Some species extend into temperate regions, including the Palearctic M. formicaria which has established in North America (first recorded in New York State).

Behavior

Waves legs in air to simulate when stationary. High-speed camera studies have shown that despite earlier assumptions, all eight legs are used for ; forelegs are raised only when stationary. Exhibits of ants to facilitate . Some change ant- targets over ontogeny—one African species was observed mimicking one ant species as and another as .

Human Relevance

M. formicaria has been to North America, where its stage has been studied using distribution models to predict spread dynamics.

Similar Taxa

BocusMorphologically indistinguishable without microscopic examination; historically confused with Myrmarachne
HeliciusFormerly included in Myrmarachne, split off as separate in 2016
PanachraestaFormerly synonymized with Myrmarachne, reinstated as in 2016
EmertoniusRevalidated in 2018 after being synonymized with Myrmarachne for nearly thirty years