R. W. CROSSKEY 



parafrontals. Lower parts of the parafrontals (outside of the fine frontal setulae) 

 and the parafacials totally bare. Wing with petiole as long as m-cu and about 

 three times or more as long as r-m (Text-fig. 87). [Small species, length under 

 5 mm, with generally blackish coloration and with the vestiture of the thorax 

 entirely black] .... subgenus HYALOMYA Robineau-Desvoidy 



Tribe CYLINDROMYIINI 



The Cylindromyiini are a nearly cosmopolitan group of long-bodied tachinids 

 that, like other phasiines, attack Hemiptera. The tribe includes the largest Phasii- 

 nae, some forms attaining a length of 17-18 mm, and is specially well represented 

 in the Oriental Region, where the fauna is composed mainly of species of Cylindromyia 

 Meigen, Hermya Robineau-Desvoidy, and - most notably - Lophosia Meigen. 

 The last-named genus, in the widened sense here adopted for it, contains a fascinating 

 array of species, some still undescribed, that show some unusual colours and patterns. 

 Despite the unusually rich regional fauna, however, the hosts of Oriental Cylin- 

 dromyiini remain almost wholly unrecorded: the pentatomid Eysarcoris inconspicuus 

 Herrich-Schaffer is a known host for two species of Cylindromyia in Pakistan, but 

 there are no records of hosts for the Oriental Region proper. 



The tribe is specially notable for including some of the most perfect mimics of 

 Hymenoptera. Mimetic forms are found mostly in the Indo-Malayan subregion, 

 in New Guinea and South America, and some species show such strong petiolation 

 of the abdomen, patterning of wings and reduction of the lower calypter, that their 

 mimetic resemblance to a recognizable model attains a high degree of precision. 

 The Oriental Formicophania elegans Townsend mimics Ropalidia binghami Vecht, 

 and some apparently unnamed Brazilian cylindromyiines are also modelled on 

 social Vespidae, apparently on species of Stelopolybia Ducke (one species mimicking 

 S. vicina Saussure and another apparently mimicking S. angulata Fabricius). 



As used in this work the tribe Cylindromyiini equates with Townsend's (1936a; 

 1938) sense of the tribe. I therefore include in it not only Cylindromyia and its 

 immediate allies, that lack palpi and have the posteroventral declivity of the thorax 

 closed, but also the forms that possess palpi and have the posteroventral declivity 

 of the thorax either open (Hermya and allies) or closed (Lophosia and allies). Some 

 authors have recognized named subtribes (Lophosiina, Hermyina) within the 

 Cylindromyiini, but I see no value in these as the tribe as a whole has a natural 

 homogeneity that prevents the so-called subtribes from being usefully defined if 

 the world fauna is considered. Some little known tropical forms possess characters 

 that would prevent their satisfactory placement if subtribes were recognized; 

 Penthosiosoma Townsend, for instance, has palpi and a closed metathorax like 

 Lophosia but has the abdominal conformation of Hermya, and Catapariprosopa 

 Townsend has the head form like Cylindromyia but possesses palpi. These, and 

 other cases of intermediates, show plainly that the subtribal classification cannot 

 be maintained. Even the 'classical' characters of open or closed posteroventral 

 declivity of the thorax and presence or absence of palpi are not as hard and fast 

 as they seem if only an incomplete series of forms is studied. In Hermya and 



