Jonathan Reisking and Herbert W. Levi.
Anatea an Ant-mimicking Theridiid Spider from New Caledonia (Araneae: Theridiidae).
Psyche 74(1):20-23, 1967.

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AiVATEA, AN ANT-MIMICKING THERIDIID SPIDER FROM NEW CALEDONIA (ARANEAE: THERIDIIDAE) BY JONATHAN REISKIND AND HERBERT W. LEVY* Museum of Comparative Zoolqg
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 Gnaohosidae Zo~ia~iidae and Eresi- dae. In addition the bizarre charactekiLics d 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 AIicarii:iae of the Cli-ibionidse) and the Aphantochilidae (a group of highly modified Thomisidae that mimic cephalotine ants). Walckenaer ( 1841 ) included in the genus Mvrnn'cia members of both the Clubionidae and the Salticidae. all good myrmecomorphs. This tendency to be biased by the outward modifications associated with ant mimici> resulted in the placing of Anatea formicaria Bei-land in the sub-Limily Alicariinae (Clubioni- dae) when it was flist described (Berlai-id, 1927). Belland based his placement on general shape and male genitalia. The latter resembles the male genitalia of Micaria, but only in that both ace quite simple and have a central sclerotized process.
'Inatea 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 Euryofiis the abdomen is sclerotized with - A
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 flavoi/uzculata 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 spicier 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. l's~rhe 74:20.23 (1967). hup Ylpsychc enlclub nrgffU74-020 html



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19671 Reiskind and Levi - Theridiid Spider 21 There are four or five other known theridiid ant mimics: Cero- cida strigosa Simon, Helvibis brasiliana (Keyserling) and H. chilensis (Keysei-ling) , the male of Coleosonia floridanurn Banks, and perhaps Hetschkia p-acilis Keyserling. All except the Colcosoina create the impression of a petiole by a posterior elongation of the cephalothorax, most highly perfected in Cerocida where the "petiole" is rugose and sharply delimited from the rest of the carapace. Coleoso~tza #oridanu7n has a highly constricted abdomen. But in Coleoswa only the males resemble ants, the females are characteristic sedentary theridiids hanging in a web.
Anatea formicaria, unlike any other tlieridiid, produces its "petiole" by an elongation of the pedicel. In addition the dorsum of the "petiole" is rugose and has a distinct "node" as is typical in most ants. The abdomen is globose and highly shiny - very much like an ant's gaster.
Anatea formicaria is an accurate mimic of the small myrmicine ant Chplaner croceivcntre (Emery), 2.6 mrn long, which has been collected at the same locality as the spider. The color pattern (dark brown anterior and light, yellow-brown posterior) of both is quite rare in ants and is also found in specimens of XIpho7nyrma tenuierms Emery, 2.9 mm long, and a species of Lordotttyrma, 4.8 mm long, two myrnicine ants found in the same area of rain forest (E. 0. Wilson, pers. comm.) . Myrmicine ants have large and well-developed stings and are therefore quite objectionable to most potential preda- tors. Such a pattern may represent a mimetic complex with the ants being 3ldlerian mimics and the spider a Batesian mimic of one or more ants.
The genus Anatea will presumably key out to Eziryopis in the key to theridiid genera (Levi and Levi 1962) but differs from Ez~ryopis in having a simpler palpus (Figs. 3-6) and from all theridiid genera in the extraordinary development of the pedicel, and the strong first legs. Berland indicates that the female resembles the male. dnatca fonmcmk Berland 1927
Figs. 1-6
Description: Male. Carapace, sternum brown and sclerotized, legs lighter brown. Dorsum of abdomen light brown with four darker areas and a polished, shiny surface. Eyes subequal in size.
Anterior median eyes about one-half diameter apart, a little more than one diameter from laterals. Posterior median eyes their radius apart, one and one-quarter diameters from laterals. The pedicel is
unusually long with a joint at each end. The chelicerae are weak



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22 Psyche [March
with fang longer than basal segment. Abdomen has a dorsal shield wrapped around it, partly covering venter (Figs. I, 2). Tracheal spiracle far anterior (Fig. 2). Legs almost equal in length; first tarsi and metatarsi thicker than tibiae. Tarsal comb on fourth legs reduced 01- absent. Total length 2.5 mm. Carapace 0.84 mm; pedicel 0.62 rnm ; abdomen 1.04 mm long. First femur, 0.63 mm; patella and tibia, 0.67 mm; metatarsus, 0.36 mm; tarsus, 0.28 mm. Second patella and tibia, 0.63 mm; third patella and tibia, 0.60 mm. Fourth femur, 0.63 mm; patella and tibia, 0.75 mm; metatarsus, 0.42 mm; tarsus, 0.34 mm.
The palpus is very simple (Fig. 3-6). Using the nomenclature of palpal sclerites used in the theridiid revisions, the median apophysis Figs. 1-6. Anatea formicaria Berland. Fig. 1. Dorsal view of male. Fig. 2. Ventral view of pedicel and abdomen.
Figs. 3-6. Left palpus. 3. Expanded,
mesoventral view. 4. Mesa1 view. 5. Ventral view. 6. Ectal view. Abbre- viations. C, conductor ; E, embolus ; S, subtegulum ; T, tegulum ; Y cymbium.



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19 671 Reiskind and Lev's - Theridiid Spider 23 is broadly joined to the embolus and the radix is absent. (It has
since been found that the "radix" of rheridiid spiders is homologous to the median apophysis of araneid spiders and the "median apophysis" to the radix).
Record:
Male from rainforest at Ciu, near Mt. Canala, 300 m, New Caledonia, 3 I Dec. 19 54 - I Jan. 19 55 (E. 0. Wilson) in the Museum of Comparative Zoology.
BERLAND, L.
1927. Sur une Araignie myrmicomorphe de Nouvelle-Caledonie. Bull. Soc. Entomol. France 95: 52-55.
KOCH, C. L.
1851. Uebersicht des Arachiden - Systems. Heft 5 : 41. LEVI, H. W. and L. R. LEVI
1962.
The Genera of the Spider Family Theridiidae. Bull. Mus. Comp. 2001. 127 (1) :1-71.
WALCKENAER, C. A.
1841. Histoire Naturelle des Insectes, Aptkres. 2: 461-4-63. Paris.



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