326 Transactions. — Zoology. 



The Queensland fly was, I believe, first recognised in that 

 colony in 1887, but it was not described until 1897, the date of 

 the report prepared by Mr. W. W. Froggatt for the Government 

 of New South Wales. This insect in Australia does not appear 

 to breed further south than Newcastle, New South Wales — about 

 our 33rd parallel of latitude ; but it has been plentifully found 

 here in fruit imported from the tropical islands situated north- 

 east of New Zealand. 



Before proceeding further it may be stated that, relying 

 solely on the results of the inspection of fruit landed at Auck- 

 land, the Mediterranean fly has not been reared here except 

 from maggots found in fruit imported from Sydney, none at all 

 having been bred from " island " fruit. As this species thrives 

 in comparatively cold climates, and attacks almost all kinds of 

 fruit, we must carefully guard against its introduction. 



When dealing with importations of fruit infested with dif- 

 ferent kinds of insects an Inspector must apply special methods 

 for their destruction before delivering such fruit to importers. 

 In the case of scale insects, which are exposed on the outside of 

 the fruit, the whole consignment is subjected to the action of 

 hydrocyanic-acid gas within an air-tight chamber for an hour. 

 This treatment destroys the insects, but does not remove their 

 scales or waxy coverings. The fly-maggots, on the other hand, 

 cannot be destroyed by artificial means, unless by burning the 

 fruit itself, as the maggot until mature or full-fed is secure within 

 the fruit, there being only a minute hole through its skin formed 

 by the ovipositor of the female fly whilst inserting her egg. When 

 an Inspector detects the presence of these maggots in a case of 

 fruit, all the other cases forming that particular consignment 

 and branded with the same mark are soon afterwards burned 

 in a furnace. As many as 450 cases belonging to one lot and 

 consigned to one importer have been destroyed in that way, 

 thereby causing a serious loss to the importer or shipper. The 

 only exception to this rule applies to the islands of the Cook 

 Group, recently annexed to New Zealand. In this instance only 

 a consignment found to be infested with these maggots may 

 be picked over under the Inspector's supervision. Each fruit is 

 examined separately : if infested it is put aside for burning, but 

 those found to be free from this pest are handed over to the im- 

 porter, who therefore only loses the infected fruit. 



During the year from 1st April, 1902, to the 31st March. 1903, 

 there were ninety-one different lots, comprising 4,119 cases, of 

 fruit condemned at Auckland alone on account of these maggots. 

 All these consisted of " island " fruit. 



The maggot of the uew species (Dacus xanthodes) does not 

 differ materially from those of the other flies specially alluded to. 



