ECOLOGY AND LIFE HISTORY OF THE 
RHYTIDOPONERA IMPRESS A GROUP 
(HYMENOPTERA:FORMICIDAE) 
II. COLONY ORIGIN, SEASONAL CYCLES, 
AND REPRODUCTION 
By Philip S. Ward 1 
Department of Zoology, University of Sydney, 
N.S.W. 2006, Australia 
Introduction 
This paper is concerned with colony foundation and with 
seasonal cycles in brood composition and alate production in the 
Rhytidoponera impressa group, a species complex of ponerine ants 
restricted to rainforest and other mesic habitats in eastern Australia 
and New Guinea. 
Life cycle information is most complete for confusa and chaly- 
baea, and most of what follows refers to those species. Relevant 
data on the other three members of the impressa group ( enigmatica , 
impressa, and purpurea ) are given where available. When pertinent 
to the discussion, some observations on related Rhytidoponera 
species outside the impressa group are also included. 
Methods 
Collection methods are described in Ward (1981). Most of the 
data are based on field observations and collections. Where ap- 
propriate, suspected reproductive females were dissected to ascer- 
tain the condition of the ovaries and spermatheca. 
Results 
Colony origin 
In the Rhytidoponera impressa group there are two methods by 
which colonies can originate: 
(i) from lone, colony-founding winged females (queens), in the 
manner characteristic of many ants; or 
‘Present address: Department of Entomology, University of California, Davis, 
California 95616 
Manuscript received by the editor April 15, 1981. 
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