[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 of Salticidae: Agorius]

Salticidae: Diagnostic Drawings Library

by Jerzy Proszynski 1997

Genus  Agorius  Thorell, 1877 

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: Agorius (6-8; 6-7), PI. 31.6. See also Koh, p. 133. The redescription and drawings of the type female in Proszynski, 1968 and the photograph in Koh, 1989 are the only recent references to this genus. For A. constrictus the cephalothorax is oblong, about twice as long as wide, slightly converging to the rear. The cephalus is raised and convex, with its posterior edge forming a transverse depression just behind the rear eyes. The basic colour is orange-brown and, on the cephalus, there is some darkening. The abdomen is very long consisting of a small oval anterior, smoothly joined to a large oval posterior by a long slender waist - a familiar shape of some ants. The oval ends are dark and the long waist is whitish. The surface is covered with sparse, erect, black hairs. The legs are long and thin. Ventrally on the slightly curved metatarsi of legs I, there is a characteristic cluster of stout spines in the apical half. The legs are lightish orange with legs IV somewhat darker and carrying hairs similar to those on the abdomen. Other species differ slightly in shape and colour. They are to be found in leaf litter in rain forest. Agorius is similar in appearance to Myrmarachne, both being particularly good ant mimics. In the field, the long, large, forward-projecting chelicerae, especially those on the males of Myrmarachne, readily distinguish this genus from Agorius. Furthermore, Myrmarachne is often to be found on vegetation above the ground.
Distribution: Agorius is known from Singapore, Sumatra, Java, Lombok, Philippines and Sulawesi. We have found undescribed species in P. Malaysia and Sabah. Murphy & Murphy 2000: 301. By courtesy of the Authors' and the Malaysian Nature Society.

Copyright © for the page by J. Proszynski, 2000.