1965] 
99 
Haskins and H / helden — Rhytidoponera 
Rhytidoponera violacea 
This is an example of one of the larger species of the genus, in 
which alate females have never been observed. It is a typical inhabitant 
of rather dry country in southwest Australia, and closely resembles in 
appearance and habit the better known R. convexa of the eastern half 
of the continent. A single colony of R. violacea taken in Kings Park, 
Perth, W. A., on December 30, 1959, was maintained in an earth- 
filled modified glass Lubbock nest through January, 1965. Through- 
out this five-year period abundant broods of young workers were 
produced, together with a few males. On October 26, 1964, 3 
cocoons were extracted from this colony and opened and their con- 
tained pupae scored for caste and sex, and a second sample of 8 was 
similarly examined on October 27. All eleven pupae were of workers. 
Thus worker production from workers was continuing four years and 
ten months after the colony was taken. 
In three of the five species of Rhytidoponera investigated (R. 
metallica , R. inornata, and R. victoriae) perfect queens are repre- 
sented in collections, though with great rarity in all except R. metal- 
lica. A fourth, R. tasmaniensis, is so closely similar to R. metallica 
that it is hard to imagine that similar alate females do not occur with 
it too, and that their absence from collections does not simply reflect 
the fact that this species has not been particularly extensively taken. 
Yet in all these species (together with the fifth, R. violacea, where 
alate females have never been found and, from all the circumstantial 
evidence, probably do not occur) worker production by individuals 
themselves morphologically indistinguishable from normal workers is 
clearly the rule. Males of the species, of course, must also be derived 
from workers. The question thus is posed whether worker production 
by workers results from thelytokous parthenogeny, or whether 
fertilization of workers, in the pattern of Diacamma, is the rule. 
THE MODE OF PRODUCTION OF WORKERS BY WORKERS IN THE 
NORMALLY “QUEENLESS” SPECIES OF RHYTIDOPONERA 
In a series of careful and extensive histological studies of workers 
of Rhytidoponera metallica , R. inornata , and R. violacea collected in 
the field, R. M. Whelden ( 1 95 7 > i960, and unpublished data) has 
conclusively demonstrated that a normal fertilization mechanism is 
involved in the production of workers by “workers.” Examination of 
the spermathecae of a total of 836 workers of these three species 
yielded the results shown below: 
