30 RK. W. CROSSKEY 
Tachinidae known to have hemipterous bugs as their hosts belong to the subfamily. 
In the past the group has often been treated as a separate family (Phasiidae), and 
certainly many of its members are very atypical looking tachinids — having widened 
coloured wings and reduced or almost non-existent chaetotaxy; but these less 
typical tachinids are interconnected with the more typical Tachinidae by many 
forms with intermediate characters and specialists are now mainly agreed on 
regarding the phasiines as a subfamily of Tachinidae. Some anomalous forms with 
coleopterous hosts such as the Strongygastrini and Palpostomatini are sometimes 
placed among the Phasiinae but it appears better, on the evidence so far available, 
to limit the subfamily to those forms parasitic on Hemiptera. 
The subfamily is moderately well represented in Australia, where all the principal 
tribes, except the Gymnosomatini, occur. There is an early record of a member 
of the Gymnosomatini from the Australian area, namely that of Macquart (1847 : 97 
(81)) who recorded a specimen of the European species Gymnosoma rotundatum (L.) 
from Tasmania, but it now seems certain that this record must be in error: Malloch 
(1929a : 112) doubted the occurrence of Gymnosoma in Australia as he had never 
seen the genus from this area, and no specimen has been found since to confirm 
its existence there. It now appears safe to conclude positively that the 
Gymnosomatini (certainly the genus Gymnosoma Meigen) are absent from Australia. 
The main characteristics of the Phasiinae are as follows. Head usually without a facial 
carina, sometimes with a distinct sublunular bulla between antennal bases, occasionally with 
weak median ridge, only with a strong sharp keel in Eutherini; rows of frontal setae (often 
weak and hair-like) descending to level of lunula or first antennal segment (rarely further); 
3 without reclinate orbital setae; head sometimes holoptic in both sexes and sometimes with 
greatly enlarged facets on upper parts of eyes in both sexes; eyes always bare; inner vertical 
setae if present parallel or crossing; arista short pubescent; prosternum and prosternal 
membrane bare; humeral callus most often with not more than two distinct setae; post ia 
setae almost always o-2 (except nearly always three in Eutherini); dorsocentral setae very 
varied, often much reduced; pre-alar seta present or absent, if present nearly always very 
small (strong sometimes in Cylindromyiini); one or two sa setae; postalar callus with not 
more than two setae; normally from one to three stf/ setae (four aberrantly) infrasquamal 
hairs present or absent; usually no definite pteropleural seta; scutellum typically with two 
or three pairs of marginal setae and without discal setae, sometimes only one pair of marginals 
(the basals, e.g. in some Alophora), rarely four pairs (some Leucostomatini), discals usually 
present in Eutherini; wing veins bare or at most with only a few minute hairs (long hairs 
occasionally in Cylindromyiini) on basal node of F,,;; mid tibia usually with v submedian 
seta (absent in some Phasiini); hind tibia with or without pu apical seta; suprasquamal ridge 
bare; abdomen with T1 + 2 excavate only at base, sometimes virtually no excavation (except 
in Eutherini where excavation reaches hind margin) ; sternites concealed or exposed; ¢ aedeagus 
with non-mobile union of basiphallus and distiphallus, distiphallus without longitudinal 
microstructures (‘POS’ type) (see Dugdale, 1960). 
Kery To AUSTRALIAN TRIBES OF PHASIINAE 
1 Wing with bend of vein M forming a gentle even curve and without trace of an M, 
appendix (Text-figs 74-75). Abdomen dorsoventrally flattened (except in Savalba 
with clavate abdomen) and usually devoid of strong setae. Abdominal sternites 
partially or completely exposed, ventral ends of tergites not meeting in the mid 
line. One supra-alar seta. One post ia seta or none. Hind tibia without pu 
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