Myrmarachne

[Title Page] [List of Genera] Comparison of Drawings] [Regional Keys to Genera] [Descriptions of New Taxa] [Geographical Distribution] [Color Photographs] See also Catalogue of Salticidae [ Title page] List of Genera - names beginning with: A BC DEFG HIJKL MN OPQ RS TUVWXYZ References: Authors beginning with: A BC DEFG HIJKL MN OPQ RS TUVWXYZ See also Catalogue: Myrmarachne]

Salticidae: Diagnostic Drawings Library

by Jerzy Proszynski 2003

Genus Myrmarachne MacLeay, 1839

COLOR PHOTOGRAPHS: assimilis by Jackson] [ bakeri by Jackson] [ plataleoides by Jackson][and by J. Koh][ formicaria Barbara Knoflach][japonica][maxillosa] [melanotarsa][3 sp. from Malaysia] [brasiliensis] [sumana] [sp. - from Amazon] [cf. chickeringi][cf. c hickeringi 2][sp. Amazon tgef02] [sp. from India: Kerala]

Diagnoses of genera of South East Asia: 51.3 Ant mimics, coloured black, brown or amber. Found on shrubs, on plants and in leaf litter. General remarks: Most, and the best, ant mimicking salticids do not prey on ants but appear to gain protection by living close to ants. These spiders are more or less coloured black, brown or amber depending on the colour of the ants they are mimicking. When running with ants, it is the movements that the spider has to make in order to avoid and keep the ants at an acceptably safe distance that signals the presence of the spider. Other, but not nearly so good, ant mimicking spiders actually prey on ants. It is fascinating and rewarding to watch one of these salticids stalking and killing an ant. Another useful clue to the presence of ant mimicking salticids is when an observer sees what appears to be an ant emerging from a silken cell!

Genus: Myrmarachne . See also Koh, pp. 127-132. Myrmarachne, with nearly 80 described species (and more to come), is by far the largest salticid genus in our area. They are good ant mimics. Typically the cephalothorax is about twice as long as wide with the cephalus raised and squarish. The join of the cephalus to the lower and narrower thorax produces a characteristic waist. The abdomen is often about as long as the cephalothorax and can be oval or long and thin, often with a noticeable waist. On Myrmarachne the pedicel is visible from above and on some species can be quite long and narrow. The overall colour varies from black, brown, yellow or even a mixture depending on the ant being mimicked. There are are often white hairs in the waists of both cephalothorax and abdomen. Professor Edmunds observed one African species of Myrmarachne whose pattern when immature mimicked one species of ant and when mature had a modified pattern which mimicked a different species of ant. The legs of Myrmarachne are long and thin, often light-coloured, with some segments of parts of segments coloured much as the body. Characteristic of Myrmarachne are the thick, long, parallel, forward projecting chelicerae of the male which can vary from about half to nearly as long as the carapace. The top of the chelicera is flat, has a keeled exterior edge and often has a formidable row of similar and equispaced teeth on the interior margin. The fangs are about as long as the chelicerae and are hooked at the tip.
Distribution: The main region for Myrmarachne is the tropical belt from Africa to Australia, but several species also occur in the warmer parts of the Old World and in the tropics and warmer parts of the New World. Murphy & Murphy 2000: 304. By courtesy of the Authors' and the Malaysian Nature Society.