Complex display behaviour during the intraspecific interactions of myrmecomorphic jumping spiders (Araneae, Salticidae)

Abstract

Jumping spiders (Salticidae) are known for their elaborate vision‐based display behaviour, and a sizeable minority of the species in this large family resemble ants. The display repertoire of two ant‐like salticid species from the Philippines is investigated. Myrmarachne assimilis is a specialist ant mimic, closely matching the appearance of the weaver ant Oecophylla smaragdina. Myrmarachne bakeri is a generalist mimic, which, although ant‐like, is not a close match to any sympatric ant species. Myrmarachne are sexually dimorphic, with males having enlarged chelicerae. The copulatory posture of Myrmarachne is unique among salticids, apparently as an adjustment for the male's elongated chelicerae. Details concerning the intraspecific behaviour of Myrmarachne appear to be adjustments to living in environments populated by numerous other animals with similar appearance (ants). However, the specialist and the generalist that were investigated have display repertoires that are broadly similar to each other and to those of more typical salticids. Generally, the display behaviour of Myrmarachne appears not to have necessitated dramatic deviation from typical salticid display and mating strategies.

Keywords:

• Arachnida
• Batesian mimicry
• communication
• conditional mating strategy
• jumping spider
• mating behaviour
• Salticidae
• signals

Acknowledgements

Work in the Philippines was generously assisted by the International Rice Research Institute. We are especially grateful to Alberto Barrion, Kong Luen Heong, and Tom W. Mew for the numerous ways in which they supported the research and to the following IRRI staff for technical assistance: Elpie Hernández, Errol Rico, Glicerio Javier, Josie Lynn Catindig and Clod Lapis. Taxonomic assistance was provided by G. B. Edwards. This research was assisted by grants to R.R.J. from the Royal Society of New Zealand (Marsden Fund and James Cook Fellowship). This study complies with the laws of the Philippines and New Zealand.