lo July, 191 2.] TJie Olive. 



405 



]'robably the worst pest in the countries referred to is the Olive Fly 

 {Dacus oleae). This insert attacks the matured and partially matured 

 fruit. In some years it works enormous damage. The Olives in Aus- 

 tralia appear, so far, to be free from its attack ; yet it is possible, nay 

 [probable, that in the warmer districts one or the other of the fruit flies 

 will take its place. Plantation owners and prospective growers must look 

 with serious concern at the possibilitv of the introduction of this fly. For 

 when once established under genial conditions, it is one of the most diffi- 

 cult to suppress. 



A closely related species, " The (Queensland Fruit Fly '' {Dacus 

 {Tephritis) Tryoni Frogg), is one of the most formidable pests with which 

 the fruitgrower in the Northern States has to contend. Any insect such 

 as this little fly, that directs its attack towards the matured or nearly 

 matured fruit, is usually most difficult to suppress. Its presence is 

 usually not suspected until it is so well established that it is difficult to 

 cope with. Although the presence of the " The Queensland Fruit Fly " 

 {Dacus {Tephritis) Tryoni Frogg.), " The Mediterranean Fruit Fly " 

 {Halterophora {Ceratitis) capitata^ Wied.), and " The Guava Fruit Fly'" 

 {Tephritis psidii) may cause serious forebodings in the Northern States 

 they are not be feared so much in Victoria. Our climatic conditions do 

 not appear to be entirely suited to their development. Doubtless many 

 of the larve were imported into Victoria in oranges and Ijananas before 

 the present system of inspection was instituted, but they do not appear 

 to have survived and multiplied. Although the Mediterranean Fruit Fly 

 has been found in several places in the Goulburn Vulle\ during the last 

 five or six years, it seems to have had a somewhat precarious existence 

 and to have done comparatively little damage. It would seem that it is 

 only in those years when the summer and autumn are especially dry that 

 its attack is to be feared. As a rule, the zone of its activity does not 

 reach so far south. The vigilance of growers should not, however, be 

 relaxed on that account, as it is possible that it may in time become 

 acclimatised. 



The three worst pests attacking the 01i\e in Australia at the 

 presenlt time are, " The Curculio Beetle." " The Olive Scale," and 

 " The Red Scale." This being so, the prospective planter has not very 

 serious cause for alarm. Providing he takes care in obtaining trees or 

 cuttings that are free from any of these pests, he is not likely to have any 

 trouble for years, unless he is adjoining an infected area. It may be 

 mentioned here, that it is the writer's intention to deal chiefly with tho.sc 

 diseases that are at present infesting the Olive groves in Australia, on'y 

 slight reference being made to those pests that have not, so far, gained a 

 foothold here. These will be dealt with separately, as they represent 

 different classes of pests and call for different methods of treatment. 



The Curculio Beetle {Ofiorhynchus crihricollis) : — This pest is 

 undoubtedly becoming one of the most serious of those attacking the Olive 

 in this country. Of late years it has been doing a considerable amount of 

 damage in the olive plantations, nurseries, and gardens of South Australia. 

 The writer has not so far met with it in the olive groves of this State, 

 although it is possible that it may be present in some places. It is to be 

 hoped that every precaution will be used against its introduction, and if 

 it gains admittance, towards its suppression, beca'.se it appears to be 

 almost omnivorous, and when once established is most difficult to sup- 

 press. When one food is not present it appears to turn its attention 

 with equal zest to another, attacking practically all kinds of fruit trees 



