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webs and egg sacs
Myrmarachne erythrocephala (QM)|
(formerly M.simoni and M. cognata and similar to M. luctuosa)
female: 7 mm|
male: 9 mm
Any surface where ants can be found. The spiders often hide under loose bark but also run with ants along established ant pathways
Probably harmless to humans
The distinguishing feature of this species is the partial constriction of the cephalothorax and/or the
abdomen into two segments to produce an ant-like body shape. The very large porrect (forward pointing)
chelicerae on the male are another striking feature. The female's palps are long and thin with paddle-shaped
ends. At least on some Myrmarachne species the cephalothorax appears to have a helmet-like shape. Note that the colour of Myrmarachne species seems to vary, at
least partly, with the colour of the ants they are running with.
The apparent differences among the images shown on this page may indicate that more than one species is presented. It should also be pointed out that the
taxonomy of the Australian Myrmarachne genus is currently being revised, the most recent example of this being the following paper: Pekar S., Petrakiva L.,
Corcobado G., and Whyte R. (2017) "Revision of eastern Australian ant-mimicking spiders of the genus Myrmarachne (Araneae, Salticidae) reveals a complex
of species and forms" Zoological Journal of the Linnean Society, 197(3), 642-676.
Myrmarachne erythrocephala appears to have been badly named since 'erythrocephala' implies a red head region which it rarely, if ever, has. It is a species that
has been found from South Queensland through NSW and probably even into Victoria. Most early specimens collected in South Queensland and NSW were initially named
Myrmarachne simoni but a few were instead called Myrmarachne cognata. Neither of these names is now considered valid but the specimens found in Southern Queensland
have been subdivided into M. erythrocepahala daemeli and M. erythrocephala erato.
Spider(s) with a very similar appearance: Many other Myrmarachne species.
Email Ron Atkinson for more information.
Last updated 2 July 2017.