79 



The members of this genus have a very wide range through Africa, India, 

 the Malay Archipelago, Australia, and some of the Pacific Islands ; a few 

 have been described from South America ; and one, the olive fly, has a wide 

 range over the Mediterranean region of southern Europe. 



The Queensland Fruit Fly. 



(PI. I, fig. 1, and PL VI.) 



Dacus tryoni, Froggatt. 



(TcpJirites Iryoni, Agricultural Gazette of New South Wale?, June, 1897, 

 p. 410, pi. 8, fig. 1. Miscellaneous publications, No. 163, 1897, 

 Dep. Agriculture N.S.W. (reprint). Agr. Gaz. N. S. W., June, 1899. 

 Reprint Misc. Pub. 303, Dep. Agr.) 



Though the maggot of this fruit-fly had been known for many years in 

 Queensland and New South Wales (it is stated as far back as 1852) as a 

 pest to fruit growers, it was not identified until Try on published his admir- 

 able observations on economic entomology (" Report on Insect and Fungus 

 Pests, No. 1, 1889,'' for the Queensland Government). He identified it as 

 the larva of a dipterous insect of the family Trypetidse and though he did 

 not give it a specific name, placed it in the genus Tephrilis, under which 

 genus I placed it when giving it specific rank under the name of Tephritis 

 tryoni , in recognition of Mr. Tryon's valuable investigations into its life 

 history and habits, contained in the above report. At this time in southern 

 Queensland it was recognised more as a peach and nectarine pest from a 

 commercial point of view, though it had been bred from nearly every kind of 

 fruit except grapes and passion-fruit. 



Since Tryon wrote, this fruit-fly has become a very much more serious pest, 

 probably partly from the extension, particularly of banana orchards, into the 

 northern parts of his State, and also from the growth of the interstate 

 fruit export trade. During the last ten years the interstate export and 

 import fruit regulations and Vegetation Diseases Acts have come into force, 

 and much more attention has been called to this fruit pest from the natural 

 anxiety of the southern States to keep it out of their orchards and to protect 

 their fruit growers. 



From observations extending over a number of years, it seems fairly evident 

 that the natural or permanent southern limit of the Queensland fiuit-ily is 

 about Gosford, in the rich brushes that extend within 50 miles of Sydney. 

 We often get this species much nearer Sydney, but it is an accidental or 

 isolated case of infestation that can be readily traced ; and unlike the 

 more cosmopolitan Mediterranean fruit-fly, I do not think that Dacus tryoni 

 will ever thrive and become a fruit-pest south of Sydney. In all the years 

 that bananas have been imported (for years without any restrictions), it has 

 had every chance of getting all over Tasmania, Victoria, and South Australia, 

 but it has never taken hold of any district south of Sydney. 



A gnat number of general reports have been written and compiled by our 

 economic entomologists on this species, but no fresh conclusions have been 

 arrived at regarding the best means of checking its ravages. Though several 

 hymenopterous parasites have been bred from the pupse, they have no 

 effect upon the increase of the pest on account of their rarity, and can only 

 be regarded as interesting from an entomological point of view. 



