FEEDING BEHAVIOR IN THE ANT 
RHOPALOTHRIX BIROI SZABo 
By Edward 0. Wilson 
Biological Laboratories, Harvard University 
Through recent work on the biology of the tribe 
Dacetini 1 , it is now known that the members of this large, 
cosmopolitan group are generally predators which feed pri- 
marily on collembolans and secondarily on other soft- 
bodied arthropods. Most are slow-moving and rely on 
stealth and the trap-like action of their mandibles in 
securing their prey. It has been an open question whether 
other groups of ants morphologically convergent to the 
dacetines, such as the tribe Basicerotini and genera 
Myrmoteras and Stegomyrmex, show similar feeding be- 
havior. Exclusively tropical distributions, scarceness, and 
small colony size have made the study of living material 
in these groups prohibitively difficult in the past. I was 
fortunate, therefore, during a recent visit to New Guinea 
to be able to find and study in life the basicerotine species 
Rhopalothrix biroi. 
This species was encountered in lowland rainforest in 
the vicinity of the lower Busu River, near Lae. Here it 
is relatively common, turning up regularly in soil-litter 
berlesates and as strays under rotting logs on the ground. 
As in other Rhopalothrix species I have collected, colonies 
were exceedingly difficult to locate. I found only one 
(my accession no. 987), occupying indistinct chambers 
about a quarter-inch below the surface in loose soil under 
a rotting log. The colony was uncovered and partly 
scattered by random scraping of the soil surface in search 
for other ants. Thirty-four workers, two males, and a 
quantity of pupae and all stages of larvae were retrieved. 
Colony cohesion was good, and there was no trouble in 
^ee Brown, W. L., 1953, Ann. Ent. Soc. Amer., 46 ’> 465-471; and 
Wilson, E. 0., op. cit: 479-495. 
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