


REVISIONARY CLASSIFICATION OF RUTILIINI 105 
shorter and more quadrate than the outer pair). The abdomen is metallic greenish 
or bluish in ground colour except for the hind margins of the tergites which are 
brownish black, and the paler bases of T3-T5 have an overlay of silvery or yellowish 
white pollinosity which gives the abdomen a transversely banded appearance. 
Paramonov (1968) drew attention to the great variability of Chrysopasta elegans, 
and presuming that all the specimens so far available are truly conspecific then 
elegans is the most variable species in the Rutiliini. Paramonov did not mention 
the male genitalia, but these too differ greatly in different specimens (Text-figs g1— 
94). This casts considerable doubt on whether elegans and its supposed synonyms 
(zabirna and versicolor) are really one species, and suggests the possibility that a 
species-complex is involved. In general it does not seem likely that several distinct 
species occur within the relatively circumscribed area of south-west Western 
Australia (where Chrysopasta is apparently confined) yet, on the other hand, it 
would be very exceptional for a single species of Rutiliini (or any Tachinid) to mani- 
fest the diversity in the male genitalia that is to be found amongst specimens of 
Chrysopasta. The diversity in the male genitalia affects not only the size and shape 
of the cerci and surstyli, but also the size of the epandrium (which in some specimens 
is much bigger in relation to the cerci and surstyli than in other specimens). The 
Text-figs 91-94 exemplify the diversity amongst different male specimens: Text-fig. 
gi shows an enlarged epandrium, very sharply pointed surstylus and very long 
tapering cerci found in a specimen from Newdegate, W.A.; Text-fig. 92 shows very 
broad foliaceous surstyli and unusually small cerci found in a specimen from 6 miles 
north of Watheroo, W.A.; Text-fig. 93 shows the shape of the surstyli and cerci in 
the holotype of elegans (exact locality unknown); and Text-fig. 94 shows the shape 
of the surstyli and cerci in the lectotype and paralectotype of zabirna from Perth, 
W.A. 
Differences in male genital form of this order in other Rutiliini would normally 
imply distinct species and would normally be correlated with some constant, if 
minor, external differences. In the case of Chrysopasta, however, there is not at 
present nearly sufficient material available to determine whether the four distinct 
forms of male genitalia so far detected are discrete entities or whether they represent 
points along a range of variability (for example, when enough material is to hand it 
might prove that there is every gradation in surstylus shape from the sharp-pointed 
form of Text-fig. 91 to the broad rounded form of Text-fig. 92). The male genitalia 
do not, on the basis of present knowledge, provide adequate evidence as to whether 
elegans is one highly variable species or a complex of species; it therefore appears 
best to retain the names zabirna and versicolor in synonymy with elegans, and to 
consider all available material as conspecific, until more evidence can be adduced. 
Variability exists in many external characteristics as well as in male genitalia. 
_ It is possible that some of the external differences may be found to correlate with the 
_ genital differences when sufficient material is studied, but no convincing correlation 
has so far been discovered. Most of the variable external features show a fairly 
_ complete gradation, e.g. the legs range from all reddish yellow to all brownish black 
and the prosternum and prosternal membrane show all conditions from bare to very 
_ strongly haired (or even bristled). Some specimens have mainly yellow pleural 
