BIDI-BIDI IN WOOL

Wanganui Chronicle, Volume 79, Issue 167, 19 July 1935, Page 6

BIDI-BIDI IN WOOL

ERADICATING PESTS INSECT FROM CHILI WANGANUI FARMERS INTERESTED ADDRESS BY DR. D. MILLER. The ciauication of bidi bidi (Or piri piri) in wool was the subject ut an address given to sheep farmers at Wanganui on Wednesday by Dr. H. Aliller. assistant director ut the Cawthron Institute (Nelson). Dr. Miller’s visit to Wanganui was the result of negotiations uial-e by Air. G. N. Bartrum, ol Maktrikiri, who for some time has been keenly interested in the elimination ci bidi-bidi from wool. The speaker was accorded a very attentive hearing ana at the conclusion of his address a committee of wool growers from this district was set up to endeavour to arrange some of the necessary finance for putting into operation a scheme outlined by Dr. Aliller. Dr. Miner said tnat the control ot bidi-bidi was a research problem wh'ch had a direct bearing on tne primary producer. Bidi-bidi was a weed restricted in range to New Zealand. Taimania and Chiii. In 1930 the question came up of attacking the problem by means of insects which would act a -’’ parasites. The Cawthron Institute A\as informed that.in Chili an insect occurred which played havoc with the pinpiri in that country. Dr. Miller accordingly went to Chiii, the only region in South America where the insects, which are known as saw-flies, arc procurable. No research wo-rk was being undertaken in this district and it aviis necessary for Dr. Aliller to obtain the insects himself and bring a supply back to New Zealand. beverai months of transport were tried and arrangements \%ere made with the British Consuls at Valparaiso and I’anama, and with the shipping companies, for shipment in cool store, said Dr. ADHer. After studying the P-*” ulem in Chili the speaker said he secured a large supply of the insects and conveyed them to New Zealand without a sing?? insect perishing. Preliminary researches were then carried odt and tests were made to see if the insects would perform the work required of them. It was very necessary to determine if the bugs would attack plant.-, of an economic value. I‘lofp. test.-, Wvre entirely satisfactory, said Dr. Aliller, and there was no reason whv the insects should not do in New Zealand what they do in ChiliDestruction of Plant. Dr. Miller said he would not guarantee that the saw-flies would destroy the piripiri m this Dominion, but he could paint a very rosy picture an 1 considered that their possibility of suecess in New’ Zealand was a very good gamble. Ur. Miller then briefly described the habits of the insect and told of how it sawed small pockets m between the leaves of the bidi-bidi plant, after which it laid its eggs and later attacked tho stock, nipping it through until the plant toppled over. The speaker remarked that considering the bug destroyed the burrs it was worth its weight in gold. There was another insect in Uhili which also attacked the bidi-bidi. This was a small beetle which was very ferocious in its attacks on the piripiri plant. Nothing Wils known about this beetle as yet, however, aud the Chilians were alsu ignorant of lts habits. Dr. Miller said that while on his last visit to Chili he brought several eggs back in coc-1 store, ihe grubs Were hatched in transit, a happening which he considered was the first of its kind in the history uf research. The possibilities of this grub, ,-»u far as eradicating bidi-bidi # would also be investigated. Dr. Aliller explained that lhe research. work has now reached the stage when the Chilian insect cun safely be liberated in the pui-piri areas in this Dominion. Further supplies aie required. on a large scale to allow for the normal percentage of mortality aud sufficient insects fur liberation, in order to do this, however, said Dr. Aliller, it would be ’necessary tor him lu attend to the work himself. This would necessitate leaving for Chili irext month. The coming season, extending frc-m Sep tender to December, was the only suitable time for collecting the insect l -. As to the result aimed at in lhe control ut piii-pni, said Dr. Miller, no absolute guarantee cgulJ be given tu advance as tu the efficiency of the Chilean parasite. “There are su many lactors about which nothing is known that influence favourably ur unfavourably an insect under field cc-nditiuns, added Dr. Aiiiler. “1. can definitely state, however, that our researches show thai this paiticular insect readily attacks the New Zealand piri piri, anti that it plays havoc, in Chui su lai as lhe plant is concerned.” Collecting the Insects. During bis previous \ isit tu- Chili, Di. Miller gained the confidence of the primitive Indians and had enlisted their aid in collecting the insects. At about September the saw-flies would start burying themselves in the ground, where remained for some months. It was essential that they be removed before they had become properly settled, otherwise the rate of mortality would be very high. Fresh earth would be used in their transportation to New Zealand, which journey, owing to there ueing no direct shipping service, was a lenglhv cue which meant crossing the equator twice. Dr. Aliller added that he. had successfully overcome these difficulties on the previous occasion, lhe trustees of the Cawthron In* si it ute were seriously handicapped by a shortage c-f funds, said Dr. Miller. The institute was privately endowed and though providing a great service for the country was run without cost to the Government or the people, if the farmers of this district were able to laise funds lor the obtaining of supplier of lhe Chilean insects, the parasites would certainly be liberated here. The matter was an urgent One and a national problem. The speaker said ho realised, however, that it. was not fair that one district should supply the cash. Tho institute, in spite ot being .short, of funds, looked upon the work as being c-f such importance toht it was willing to pay £2OO towards the cost. At the conclusion of his address, DrAliller answered several questions and explained how in Chili one would go l fop miles without seeing any piri piri plant. It was usually io l»c found J' l

patches. A parasite Mould never completely eliminate a P es t, but would reduce the trouble until it was no longer of economic importance. £•> an»wer to a further query, Dr. AiiHyr said that the insect could be reared i n New Zealand, but a long time would elapse before it was effective. The speaker was aecC'rdod a heaHy vote of thanks and a committee was sei, up with a view to endeavouring t“ raise funds for the expedition to Chil l next month.