168 R. W. CROSSKEY 



forestry, there has not up to now been any published host-list for the Australian 

 Tachinidae. The only published host records available have been scattered in 

 original tachinid descriptions or cited haphazardly in departmental reports or in 

 accounts of particular pests, and these were the main sources for the relatively few 

 entries in W. R. Thompson's A Catalogue of the Parasites and Predators of Insect 

 Pests concerned with Australian Tachinidae. Many of the earlier records existing 

 in these various publications cannot be relied upon, either because of changes 

 in the nomenclature of the hosts and parasites or because of misidentincation, 

 especially of the tachinids, and for some time an up-to-date host catalogue for the 

 Australian Tachinidae has been needed that is based so far as possible on reliablv 

 named hosts and parasites and on the latest information available. 



The host catalogue here presented may not be exhaustive, as there are probably 

 some tachinid specimens scattered in Australian collections that were reared from 

 known hosts but have not been available during the present study. Nevertheless 

 the lists of hosts and parasites are sufficiently comprehensive to form useful basic 

 lists that can be gradually augmented as more evidence on the host-relations is 

 acquired. 



A major difficulty in compiling dependable host-parasite lists is the unreliability 

 of the identifications. As a rule, material of the hosts is not kept in collections 

 with the reared Tachinidae so that confirmation of identity of both host and 

 parasite is difficult or impossible. In general, however, it is likely that the hosts 

 will have been correctly identified, since they are commonly well known pests and 

 often are conspicuous Lepidoptera whose specific identities are not in doubt (even 

 if the lepidopterists are in dispute about the generic placements). On the other 

 hand identities of tachinid parasites are likely to be wrong unless they have 

 been recently checked by a specialist on the group (and in some difficult groups 

 of tachinids even this is no gaurantee for every specimen). In preparing the 

 accompanying parasite-host and host-parasite lists it has been assumed that the 

 hosts have been correctly identified, but the tachinids have only been recorded 

 when: (i) they have been personally identified, (2) when the host record is from the 

 original type-material of the tachinid parasite, or (3) when published records, 

 other than the original descriptions, are undoubtedly based on correctly identified 

 Tachinidae. The last circumstance is relatively infrequent, and most host records 

 in the literature have been discounted because the identities cited for the tachinid 

 parasites are either wrong or suspect (for example, most of G. H. Hardy's 

 identifications of Australian Tachinidae were based on guesswork from the 

 literature and in consequence were often in error: hence his published host records 

 have usually been discounted) . 



The information for the host catalogue derives largely from specimens in the 

 collection of the British Museum (Natural History). Many of these specimens 

 have been received from time to time as duplicate specimens submitted to the 

 Commonwealth Institute of Entomology for identification, usually by Australian 

 state departments of agriculture and forestry; for this reason the BMNH collection 

 is more comprehensive than any other in Australian Tachinidae reared from known 

 hosts, and the host catalogue is almost as completely comprehensive as it is possible 



