AN ATE A, AN ANT-MIMICKING THERIDIID SPIDER 
FROM NEW CALEDONIA (ARANEAE: THERIDIIDAE) 
By Jonathan Reiskind and Herbert W. Levi* 
Museum of Comparative Zoology 
The morphological and behavioral adaptations necessary for ant 
mimicry have arisen independently many, many times in spiders. Ant 
mimicry has originated at least four times in the Clubionidae, three 
times in the Salticidae, several times in the Theridiidae, Araneidae 
and Thomisidae, and also in the Gnaphosidae^ Zodariidae and Eresi- 
dae. In addition the bizarre characteristics of these spiders have led 
spider specialists to group some of the stranger species into families 
— such as the Myrmecidae C. L. Koch 1851 (mainly including ant- 
mimicking genera from the Micariinae of the Clubionidae) and the 
Aphantochilidae (a group of highly modified Thomisidae that mimic 
cephalotine ants). Walckenaer (1841) included in the genus 
Myrmecia members of both the Clubionidae and the Salticidae, all 
good myrmecomorphs. This tendency to be biased by the outward 
modifications associated with ant mimicry resulted in the placing of 
Anatea formicaria Berland in the sub-family Micariinae (Clubioni- 
dae) when it was first described (Berland, 1927). Berland based his 
placement on general shape and male genitalia. The latter resembles 
the male genitalia of Micaria, but only in that both are quite simple 
and have a central sclerotized process. 
Anatea formicaria Berland should be in the family Theridiidae. 
Closely related to Euryopis and possibly to Achaearanea , it lacks a 
colulus and has toothless cheliceral margins. The palpus, which lacks 
a radix, is simpler than in either Euryopis or Achaearanea but is defi- 
nitely related. As in some Euryopis the abdomen is sclerotized with 
scuta and the chelicerae are very small with huge sickle-shaped fangs, 
possibly indicating that Anatea feeds on ants as do members of 
Euryopis and related Dipoena. The function of the sickle-shaped 
fang is not known although the unusual method used to catch ants 
by Euryopis flavomaculata C. L. Koch has been observed (D. Hirsch- 
berg in manuscr.). While it is unlikely that the mimicry would 
deceive an ant, the occurrence of the spider near the ants (a prey- 
predator relationship) could account for strong selection pressure 
applied by predators of the spider. 
*This investigation was supported in part by Public Health Service 
Research Grant AI-01944 from the National Institute of Allergy and 
Infectious Diseases. 
Manuscript received by the editor April 3, 1967. 
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