WHOLE VOL. APrr.IED ENTOMOLOGY HOWARD 535 



large acres of valuable grazing land. It seems unlikely that any of 

 the insect enemies of Opuntia would attack cultivated crops of any 

 value; and therefore the Australians were quite justified in their 

 large-scale attempts to import into Australia and establish there the 

 insect enemies and diseases of the plants of this genus. 



A Prickly-Pear Board was established in Queensland, and Prof. 

 T. Harvey Johnston and Mr. Plenry Tryon were sent on a world hunt. 

 They visited Washington in 191 3, and were advised to go to Texas 

 and consult with W. D. Hunter, F. C. Pratt, and J. D. Mitchell of the 

 United States Bureau of Entomology, who had been studying cactus 

 enemies for some time. Eventually a laboratory for the Prickly-Pear 

 Board was established at Uvalde, Texas, and many important insects 

 were sent over. Cactus-feeding insects were also sent in from other 

 parts of the world. Certain species have become established and have 

 proved very effective, destroying the injurious plants over large tracts 

 of land. 



Hawaii, suffering from the increase of the Lantana weed, sent 

 agents to several countries to seek for the insect enemies of this weed. 

 A fly affecting the seed was found and introduced and multiplied to 

 such an extent that the Lantana pest was greatly reduced. 



This Lantana seed fly was introduced from Hawaii into Fiji prior 

 to 191 6 and was reported in that year by F. P. Jepson to have become 

 so thoroughly established that it was not possible to find Lantana 

 within several miles of Suva that did not display evidence of attack 

 by this insect. 



Similarly the same fly was introduced into Queensland from 

 Hawaii, as announced in the Queensland Agricultural Journal for 

 April, 1917. 



Australia is not the only part of the world to introduce enemies 

 of Opuntia. G. Pettit, in the Proceedings of the French Academy of 

 Agriculture in 1929, announced the successful introduction of Dac- 

 fylopiiis coccus into ]\Lidagascar to destroy Opuntia vulgaris. He 

 made the statement that in one large tract of 25,000 acres the cactus 

 was completely destroyed in eight months. In the review, no state- 

 ment is made as to the place from which the Dactylopius was 

 imported. 



The destruction of Opuntia on the Island of ^^lauritius by the 

 different imported insects has also been tried. 



Dr. R. J. Tillyard for several years before leaving New Zealand 

 for Australia interested himself in the importation of insect enemies 

 of the blackberry, blackberry plants having gone wild over large 

 sections of land and having become a great pest. Doctor Tillyard, 



