TACHINIDAE OF AUSTRALIA 167 



positively to provide hosts, and these same orders provide the hosts for the 

 overwhelming majority of world forms: the Lepidoptera and Coleoptera, as elsewhere, 

 provide the greatest number of different host species, and the Orthoptera, 

 Hemiptera-Heteroptera and Hymenoptera are regularly parasitized by particular 

 groups of Australian tachinids; a few species of stick-insects (Phasmatodea) and 

 mantids (Mantodea) also provide hosts. The rather well developed fauna of 

 Embioptera in Australia is not known to have tachinid parasites, but may be found 

 to do so (as the tachinid genus Rossimyiops Mesnil is parasitic on an embiopteran 

 in South Africa). There is one remarkable record of an Australian tachinid 

 parasitizing adult Tabanidae (Diptera) (Spratt & Wolf, 1972). 



Tachinids are presumed to play an important role in the natural regulation 

 of the numbers of their hosts, but this is difficult to quantify. In Australia many 

 of the economically important insect pests are attacked by tachinid parasites, 

 and some parasite species are regularly reared in numbers from their host pest 

 species. Particular tachinid groups may be confined to particular host groups 

 (e.g. the Phasiinae only attack Hemiptera and the Acemyini only attack 

 Orthoptera) but true host-specificity in the sense of a single species of parasite 

 confined to a single host-species is apparently rare in the Australian fauna (and 

 the apparent instances where host-specificity occurs are probably mainly due to 

 insufficient knowledge). Certainly several of the main injurious pests are attacked 

 by several species of tachinid, and many of the tachinids attacking these pests 

 also have other hosts (as is evident from the accompanying parasite-host and 

 host-parasite lists). 



The range of economically important Australian insect pests that are attacked 

 by Tachinidae is very diverse, and includes pests of agricultural crops (sugar-cane, 

 cotton, maize, cucurbits) and many serious defoliators of forest timbers. Some 

 of the most important pests, with their parasite-groups, are: the cotton bollworm 

 (Heliothis armigera), the army-worm (Persectania, Pseudaletia, Spodoptera spp.) 

 and cutworm (Agrotis) pests of cotton and other crops that are attacked by many 

 species of Tachininae and Goniinae; the sugar-cane borer weevil (Khabdoscelus 

 obscurus) attacked by Lixophaga sphenophori; the white-grub larvae of melolonthine 

 beetles, especially the sugar-cane white-grub (Dermolepida albohirta) of the 

 Queensland canefields, attacked by species of Palpostoma and of Rutiliini; the 

 introduced scarabaeid beetle Heteronychus arator, a pest of maize in New South 

 Wales, that is attacked by species of Palpostoma; the chrysomelid beetle 

 Atdacophora hilaris that destroys the foliage and flowers of cucurbitaceous crops, 

 attacked by a species of Blondeliini; the cotton-stainer bug (Dysdercus sidae) of 

 Queensland, attacked by species of Phasiinae; the pergid sawfly defoliators of 

 Eucalyptus, attacked by several species of the Anagonia-Froggattimyia complex 

 (Blondeliini); the chrysomelid beetle Paropsis atomaria, a pest of Eucalyptus, 

 attacked by several species of Blondeliini; and the stick-insect Didymuria violescens, 

 a serious defoliator of Eucalyptus in New South Wales, that is attacked by an 

 undescribed tachinid of very uncertain systematic position. 



Despite the diversity of economically important insect pests, and the extent 

 of work undertaken on them by Australian departments of agriculture and 



