3 o R. 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); 

 (J 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 0-2 (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 stpl 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 i? 4+5 ; mid tibia usually with v submedian 

 seta (absent in some Phasiini) ; hind tibia with or without pv apical seta ; suprasquamal ridge 

 bare; abdomen with Ti -f- 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, 1969). 



Key to Australian Tribes of PHASIINAE 



Wing with bend of vein M forming a gentle even curve and without trace of an M 2 

 appendix (Text-figs 74-75). Abdomen dorsoventrally flattened (except in Saralba 

 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 pv 



