32 
Records of the Australian Museum (2009) Vol. 61 
group of Drosophila s.str. There is no indication in these 
studies that Patterson & Wheeler (1942,1949) examined the 
D. setifemur holotype or paratype held in Sydney or either of 
the two paratypes held in the USNM (Lee et al., 1956) before 
they included it in the immigrans species group. 
Species of the immigrans group are collected at fruit and 
breed easily under culture making them ideal for genetic 
studies. The University of Melbourne geneticist, A.M. 
Clark, reported that between Malloch’s 1924 publication 
and 1951 no further reports or collections of D. setifemur 
“seem to have been made” (Clark, 1957). If Clark was 
guided by the classification of Patterson & Wheeler (1949), 
and there is no reason to suspect otherwise, he would have 
been looking for a species differing only slightly from 
the cosmopolitan species D. immigrans ; no such species 
exists in southeastern Australia (a region where the major 
cities are Melbourne, Sydney and Brisbane). In northern 
Australia, however, several species of the immigrans 
species group are abundant. Clark wrote (1957) that, in 
July 1951, he was able to obtain a few individuals of 
“ D. setifemur ” from Drosophila collections made with 
fermenting banana bait in the vicinity of Cairns, northern 
Queensland. His determination of these tropical Australian 
flies as D. setifemur was a mistake. The flies were most 
probably D. sulfurigaster, a fruit-breeding species now 
known to be very common in Cairns but a species then 
not reported from Australia. (It is important to note that, in 
1957, very little had been published about Drosophilidae 
from tropical Australia.) The consequences of Clark’s mis- 
identification were further compounded by his decision 
to re-describe D. setifemur based on these newly collected 
specimens (Clark, 1957). With hindsight it is not surprising 
that Clark’s redescription of D. setifemur closely matches 
D. sulfurigaster not D. setifemur s.str. Clark nominated no 
voucher specimens and appears not to have examined the D. 
setifemur type in Sydney. It is also apparent that he had not 
noticed a list, published by Mather just several years earlier 
in 1955, of species collected in northern Queensland; the 
list included D. spinofemora (= D. sulfurigaster ) from sites 
near Cairns, not D. setifemur s.str. 
Clark (1957) found that the strain he determined to be 
D. setifemur (but which was probably D. sulfurigaster ), 
hybridized freely with D. spinofemora (later shown to 
be a synonym of sulfurigaster ), and so he considered it 
a useful model for comparative genetics. Twelve years 
later, in a wide-ranging study, the two were both placed 
in synonymy (Wilson et al., 1969) with a third species D. 
sulfurigaster (type locality Madang, Papua New Guinea), 
which is widely distributed throughout the Pacific, tropical 
Australasian and Oriental Regions. Once again the holotype 
of D. setifemur appears not to have been examined. Rather, 
it seems likely that Wilson et al. (1969) relied too heavily on 
Clark’s redescription and hybridization experiments which 
incorrectly concluded that “D. setifemur ” was a species 
morphologically indistinguishable from D. sulfurigaster 
and one that hybridized freely with it. Wilson et al. (1969) 
may also have accepted, at face value, Mather’s line of 
argument. In reference to the northern Queensland records 
of “D. setifemur” (see Clark, 1957) and “D. spinofemora” 
(see Mather 1953,1955), Mather (1960:237) wrote: “In view 
of the fact that D. setifemur and D. spinofemora have been 
shown to be sibling species (Clark, 1957) and D. setifemur 
is here shown to be abundant in northern Queensland, it 
seems likely that what was previously referred to as D. 
spinofemora was indeed D. setifemur ”. And finally, Wilson et 
al. (1969) may have been aware of, and influenced by, a then 
contemporaneous study by Mather, Baimai and Bock (1969) 
in which D. setifemur was incorrectly reported as common 
at fruit baits at five localities in Papua New Guinea. 
The resulting confusion about the true identity of D. 
setifemur can be attributed firstly, to the false assumption 
that it had not, after 1924, been re-collected near Sydney; 
secondly, to its incorrect classification in the immigrans 
species group; thirdly, to its redescription based on specimens 
of D. sulfurigaster, fourthly, to incorrect records of its 
frequent occurrence at fruit bait in the Australasian tropics; 
and finally, to the fact that Malloch had described only 
females and had not reported the very distinctive sexual 
dimorphism in this species. 
When Bock (Bock, 1976) undertook a major review 
of Australian Drosophila species he followed Wheeler 
(in Wilson et al., 1969, see above) and accepted that 
D. setifemur was a junior synonym of D. sulfurigaster. 
However, he and other Australian Drosophila biologists— 
particularly Mather, Barker and Parsons—had accumulated 
extensive biogeographic data showing conclusively that D. 
sulfurigaster occurred neither in New South Wales (Bock 
& Parsons, 1978) nor in southern Queensland (Mather, 
1955; but see van Klinken, 1996: 101). It therefore puzzled 
Bock (1976: 10) that Malloch had apparently described a 
common tropical species—one never found south of 20°S 
latitude—from four specimens collected in Sydney at 
34°S. Had D. sulfurigaster once occurred in Sydney? Had 
there been an error in application of label-data? Or was D. 
setifemur not actually a synonym of D. sulfurigaster, was it a 
species known to be common in eastern temperate Australia 
under a different name? 
Recent re-examination of certain type specimens in 
the Australian Museum, Sydney, curation of several 
hundred ex-SPHTM specimens accessioned in 1987 and 
assimilation of tens of thousands of eastern Australian field 
records (author’s collections 1980 to present), has led to 
a re-assessment of D. setifemur. Among the ex-SPHTM 
material were additional specimens that had, around 1924, 
been classified, probably by Malloch or by F. H. Taylor, 
as being conspecific with D. setifemur. Such information, 
together with a better understanding of the biogeography 
and composition of the eastern Australian drosophilid fauna 
and examination of the setifemur holotype, has answered the 
questions posed above. Drosophila setifemur Malloch, 1924 
is not a junior synonym of D. sulfurigaster, it is a senior 
synonym of D. dispar Mather, 1955. 
Specimens referred to in this study are held in the following 
museums: 
AMS 
Australian Museum, Sydney. 
ANIC 
Australian National Insect Collection, CSIRO, 
Canberra. 
BMNH 
The Natural History Museum, London. 
BPBM 
Bernice P. Bishop Museum, Honolulu. 
QM 
Queensland Museum, Brisbane. 
SPHTM 
former School of Public Health and Tropical 
Medicine, University of Sydney, acalyptrate 
flies now incorporated in AMS. 
USNM 
United States National Museum (Smithsonian 
Institution), Washington. 
