EVIDENCE OF WORKERS SERVING AS QUEENS 
IN THE GENUS DIACAMMA 
(Hymenoptera: Formicidae) 
By Mark W. Moffett 
Museum of Comparative Zoology, Harvard University, 
Cambridge, Massachusetts 02138 
There is no morphologically distinguishable queen caste known in 
the ponerine genus Diacamma. Wheeler and Chapman (1922) 
observed a typical Diacamma worker copulating with a normal 
male, and it has been assumed that some workers are functioning as 
reproductives. I report an experiment that supports this view. 
Ants in the D. rugosum complex at Sullia in Karnataka State, 
southern India, live in polydomous colonies; foragers move freely 
between nests within a colony, which are separated by one to several 
meters. Each nest is a blind-ended tunnel 10-25 cm deep containing 
brood and between about 50-120 workers. When individual nests 
within a colony were collected and kept in captivity, some workers 
foraged frequently, while the remainder never left the artificial nest 
tubes. 
In a preliminary experiment conducted during February and 
March, 1982, the ants taken from one nest were sorted into foraging 
and non-foraging behavioral types and then further divided into 
groups of 5-6, with eight groups of foragers (total 45 ants) and four 
groups of non-foragers (total 21 ants); every group was provided a 
separate test tube “nest” with stoppered water source and no brood. 
The foraging ants continued to come and go from their nest tubes, 
and in none of these groups were any eggs produced over a period of 
a month. Non-foraging ants continued to stay within their nest 
tubes and eventually had to be provided food within the tubes. In all 
four non-foraging groups the test tubes soon held brood, and the 
five immatures that survived to the pupal stage (three from one tube 
and two from another) were workers. 
This indicates that part of the worker population is fertilized and 
is serving as queens, as is the case with the African ponerine 
Ophthalmopone berthoudi (Peeters and Crewe, 1984, 1985), which 
also lacks winged gynes. 
I am grateful to R. Gadagkar and M. Gadgil for aid during my 
stay in India. 
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