PRICKLY PEAR MENACE.

Otago Daily Times, Issue 18952, 28 August 1923, Page 8

PRICKLY PEAR MENACE.

RAVAGES IN QUEENSLAND. , METHOD OF COMBATING IT. PROBLEMS FOE AGRICULTURISTS. Th© people of New Zealand have no conception of the terribly devastating effect of prickly pear on the vast region of valuable country in Queensland where this pest has strongly entrenched itself, but Mr J. A. Pond, formerly Government analyst, who baa been on a visit to the Australian State mentioned, said in Auckland a few days ago (says the New Zealand Herald) that between 40 and 50 million acres, of very fine land was in the grip of this formidable plant. Mr Pond explained that he went to Queensland expressly to study this problem, on which the ingenuity of scientists has been expended, and was willing to give his services gratuitously to the Government in the efforts being made to release the land from the prickly pear, but he was satisfied the method being followed was the only one which showed promise of achieving practical results. This consisted in the propagation ol the insect known as the wild cochineal, which attacked the plant and killed it right down to the roots, and its use on the particular variety of the pear which had spread over Queensland had resulted in a very large area being cleared. The officers in charge of the work, starting with 20 of these living creatures, had raised millions of them. Tho insects were then allowed to attack the pear in a specially prepared reservation, and sections of the plant were then distributed among the wild wastes to enable the insects to transfer their attentions to the real pest. There was danger, however, of the insects being killed out by parasites, such os one of t£e ladybird species, but great care was being taken to raise the cochineal to ensure its being distributed without carrying its own particular enemy with it. Speaking of tho many other attempts to eradicate tho pear, Mr Pond said that the Queensland authorities had experimented with arsenic acid combined with sulphuric acid, and last vear had sold 134 tons of this mixture to settlers at o price well below coat. The effect of spraying with this mixture was that the sulphuric acid burned through the outer skin and the arsenic attacked the heart, resulting in the plant dying down. The cost of this treatment, was very high, and Mr Pond was of opinion that the cochineal was more effective, ns the plant was killed right to the roots. When cleared, the land is rich, and suitable for almost any agricultural purpose, but it requires water, which has in many instances to bo brought great distances. In this connection, Mr Pond said tho whole of the State had suffered severely from the recent drought, and the effect was more pronounced than in former years by reason of the fact that greater areas of country had been brought into cultivation. Agriculturists were faced with many’ problems, for many pests were well 'established, among them the lantana, a quick-growing plant, which has also proved a serious problem in Fiji. This plant is now all over Queensland. In tho southern portion of tho State the_ banana growers are fighting bunchy top. which is spreading and killing out many plantations. Tick is also prevalent, and conditions are not improved by the serious Inroads of hookworm, in the north, particularly, and the summer attacks of the meequito.