74 R. W. CROSSKEY 



Phyllomya gibsonomyioides sp. n. differs from other Phyllomya species in having 

 the holoptic male head that lacks prevertical and proclinate orbital setae. In this 

 respect it resembles the genus Gibsonomyia, hence the specific name chosen for it. 

 From P. elegans Villeneuve - the only other Phyllomya species recorded from the 

 mountainous border areas between the Palaearctic and Oriental Regions - it differs 

 (in addition to the male head) by several characters as indicated in the foregoing 

 key. 



Tribe THELAIRINI 



The characteristics of typical Thelairini have been detailed elsewhere by Crosskey 

 (19736 : 63) and Mesnil (1975a : 1334) and need not be cited here. The tribe occurs 

 in all the major zoogeographical regions and its members (for which hosts are 

 known) are parasites of Lepidoptera. Ten genera occurring in the Oriental Region 

 are here placed in the Thelairini, but mainly an account of their general external 

 resemblance to Thelaira, and it is possible that more critical work in future will 

 show that certain genera would be better placed elsewhere. In particular may be 

 mentioned the genus Prosheliomyia Brauer & Bergenstamm of which the external 

 facies is very like Thelaira, but which Townsend (19366 : 74) and Verbeke (19626 : 

 126, under the synonymous name Holiday opsis Townsend) considered to be allied 

 to Thrixion Brauer & Bergenstamm. It is possible that the resemblances between 

 Thelaira and Prosheliomyia are convergent, as may be the obvious external similarity 

 between the latter genus and the genera of Acemyini (in which tribe Townsend 

 placed both Prosheliomyia and Thrixion). 



The genera Halydaia Egger and Allolhelaira Villeneuve (syn. Sisyropododexia 

 Townsend) are undoubtedly very close phyletically, as Verbeke (19626 : 100) shows, 

 and both can unequivocally be placed in the Thelairini. The correct affinities of the 

 little known genera Polygastropteryx Mesnil and Actinochaetopteryx Townsend 

 (with its apparent ally, Thryptodexia Malloch), for which the hosts are unknown, 

 are much more problematical but it seems best for present purposes to place them 

 in Thelairini. This is an interim measure, but agrees at least with Townsend's 

 treatment (for he placed Polygaster Wulp, a very close ally of Polygastropteryx, and 

 also Actinochaetopteryx in his Thelairini), and with Mesnil's (1975a) placement for 

 Actinochaetopteryx. It may well be the case, however, that the phyletic relationships 

 of Polygastropteryx lie with the acemyines as Verbeke (19626 : 126) implied. Mesnil 

 (1975a : 1346) has given a key to the species of Actinochaetopteryx. 



The curious genus Torocca Walker (which is very unusual among Tachinidae 

 in general because of the presence of median discal setae on abdominal Ti + 2) 

 so much resembles the Thelairines that it should be placed in this tribe at least 

 for the time being, despite the very different arrangement of the scutellar bristles. 

 (Here it must be mentioned that Verbeke (19626) confused Doleschalla Walker with 

 Torocca Walker; the genus referred to as Torocca throughout Verbeke's paper is 

 actually Doleschalla, a very different genus belonging to the Proseninae, and the 

 true Torocca Walker was not studied by Verbeke.) I am not convinced on evidence 

 so far available that Torocca should be placed in Doleschallini as Mesnil (1975a : 1348) 

 assigns it. 



