THE DACETINE ANT GENUS 
PENTASTRUMA (HYMENOPTERA: FORMICIDAE) 1 
By William L. Brown, Jr. and Ronald G. Boisvert 
Department of Entomology 
Cornell University, Ithaca, New York 14853 
The genus Pentastruma was established by Forel ( loc . cit. infra) 
on the basis of a single Taiwanese worker specimen that he 
described (P. sauteri ) as having 5 antennal segments, a very unusual 
number even for a member of the Dacetini, to which tribe he 
indicated that it belonged. In several ways, the description read as 
though based on a depilated species of Smithistruma, and when, 
several years ago, Dr. Masao Kubota sent specimens of a nearly 
hairless short-mandibulate dacetine from Japan, WLB suspected 
that it might be close to Pentastruma sauteri, despite the fact that its 
antennae displayed the 6-merous condition usual in strumigenite 
dacetines. 
Now we have finally discovered the location of the Hans Sauter 
Collection of Taiwanese ants, in the Institiit fur Pflanzenschutz- 
forschung (BZA) der Akademie der Landwirtschaftswissenschaften 
der Deutsche Demokratik Republic in Eberswalde. Through the 
kind offices of Dr. G. Morge we have been able to borrow some 
critical formicid types from the Sauter material, among them the 
unique specimen of Pentastruma sauteri. This worker proves to be 
close to the Japanese species received from Dr. Kubota, but it is 
specifically distinct. It does also have 6 antennoineres, with the 
normal strumigenite proportions, and not 5 as stated by Forel. In its 
general form, P. sauteri is a rather typical Smithistruma, except for 
its complete lack of standing or other conspicuous hairs on head, 
trunk and petiole, and the new Japanese species matches it in these 
respects. 
It seems logical that Pentastruma should eventually be merged 
with Smithistruma, but the latter genus is itself not stable at this 
*A report of Research from the Cornell University Agricultural Experiment 
Station, New York State College of Agriculture and Life Sciences. The research was 
supported by National Science Foundation Grant GB-31662. 
Manuscript received by the editor September 15, 1978. 
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