William L. Brown, Jr.
Ctenobethylus (Bethylidae) A New Synonym of Iridomyrmex (Formicidae, Hymenoptera).
Psyche 83:213-215, 1976.

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CTENOBETHYLUS (BETHYLIDAE) A NEW SYNONYM OF ZRZDOMYRMEX (FORMICIDAE, HYMENOPTERA)' BY WILLIAM L. BROWN, JR.
Department of Entomology, Cornell University Ithaca. New York 14853
In 1939, in a paper describing several new genera and species of Baltic Amber Hymenoptera, C. T. Brues erected Ctenobethy- lus succinalis gem et sp. nov. for a single specimen of what he took to be an apterous female bethylid. I recently chanced upon this description, and was immediately struck by the ant- like habitus of the type as portrayed in Brues' fig. 7. It was also noted that the figure showed only 12 antennomeres, although Brues had made a diagnostic point of claiming "13-jointed" antennae for his genus.
My suspicion that the type of C. succinalis is actually a worker ant of the dolichoderine genus Zridomyrmex was confirmed when it was sent for my study. The specimen has the legs folded up so as to obscure the waist, which explains why Brues did not see the petiolar scale. In the preparation as it now stands, however, the scale is partly visible in a left-side view, although it is covered with a white film. The specimen also has 12-merous antennae, and in fact closely corresponds to small-sized workers of Iri- domyrmex goepperti with which I have compared it directly. Although I have not seen the type of 1. goepperti, I compared 11 worker specimens of this commonest of all Baltic Amber ants lent from the Museum of Comparative Zoology collection. (1. goepperti made up over half of the more than 10,000 Baltic Amber ants determined by W. M. Wheeler at one time or another; see Wheeler, 1914: op. cit. infra, p. 8.) These specimens and the C. succinalis type meet very well the available descriptions of 1. goep- perti. The formal synonymy is:
'A Report of Research from the Cornell University Agricultural Experiment Station. Research supported by National Science Foundation Grant DEB75-22427. Manuscript received by the editor November 16, 1976



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214 Psyche [June
Iridomyrmex goepperti
Hypoclinea gopperti Mayr, 1868, Beitr. Naturk. Preuss. 1: 56, pi. 1, fig, 3-7; pi. 3, fig. 42-46, worker, queen, male.
Iridom,vrmex goepperri: Wheeler, 1914, Schrift. Phys-okon. Ges. Koenigsberg, 55: 90-9 1, worker.
Ctenobethylus succinalis Brues, 1939, Ann. Entomol. Soc. Amer. 32: 261-263, fig. 7, Q (recte worker). Type: Museum of Comparative Zoology, Harvard University, No. 7666. NEW SYNONYM.
Brues' figure errs in omitting the spurs, present one on each tibia1 apex, and also in showing the trunk as without an impressed metanotal groove; actually, this groove is distinctly though mod- estly impressed in the type.
I. goepperti is left in Iridomyrmex for the time being, although this genus is almost surely a diphyletic assemblage. The Indo- Australian species, including the type species of Iridomyrmex, 7. purpureus (=I. detectus), differ from the New World members (7. humilisgroup) in that they lack Pavan7s apparatus (with gland) at gastric sternites IV and V. The status of the Baltic Amber Iridomyrmex with respect to this character has not been deter- mined, because the few samples available to me have the under- side of the gastric apex obscured by films. As already stressed by Wheeler, I. goepperti lacks a distinct epistomal (frontoclypeal) suture and frontal triangle, conditions atypical for Iridomyrmex (and for ants in general). It is likely also that the living species of Iridomyrmex divide further into groups on the basis of pro- ventricular anatomy, position of compound eyes, larval mor- phology, karyotype, and perhaps other characters. If some of these groups represent different genera, as seems likely, we do not know yet how the divisions will cut, or what genus-level names are available.
The "Iridomyrmex Problem" is an exceptionally complex one, calling for nothing less than a full-scale revision of the Tapinomini. Until that revision can be made, the genus Iridomyrmex is best left as it stands, and Ctenobethylus, with type and sole species C. succinalis, is its new synonym.
In recent correspondence with E. 0. Wilson and H. E. Evans, I learned that they had jointly examined Ctenobethylus succinalis several years ago, and tentatively considered it to belong to Iridomyrmex, but they did not complete the study. I am grateful



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19761 Brown - Ctenobethylus 215
for their opinions, but since the present study was made inde- pendently, they should not be held responsible for my conclu- sions. F. M. Carpenter has my thanks for the improved prepara- tion and the loan of the C. succinalis type.



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