NO. OF ITEMS 
1981] 
Ward — Rhytidoponera impressa. I 
105 
Figure 3. Frequency distributions of the lengths of food items taken from 80 
chalybaea foragers and 19 croesus foragers (see Tables 5 and 6). Each distribution is 
based on workers from one colony only. 
size distributions are based on limited single-nest samples, and there 
is likely to be significant temporal and spatial heterogeneity within, 
as well as between, species. 
Additional studies on food item diversity and overlap in Rhy- 
tidoponera are desirable. Such studies are feasible for ants which are 
primarily lone-foraging predators and scavengers, because of the 
discrete, visible nature of most foraged items. However, difficulties 
remain in assessing the importance of honeydew and other liquid 
foods, which may be carried in the crop as well as between the 
mandibles. 
Two species in the impressa group were recorded collecting 
honeydew from homopterans. Workers of chalybaea were seen 
tending coccids on a fresh shoot emerging from the trunk of a 
camphor laurel tree ( Cinnamomum eamphora), in the Sydney 
region. R. purpurea workers were observed tending aphids on 
ginger plants ( Alpinia caerulaea ) in several places at Lake Eacham, 
Qld. 
