WAR AGAINST RAGWORT

Sun (Auckland), Volume III, Issue 927, 21 March 1930, Page 6

WAR AGAINST RAGWORT

SCIENTIFIC RESEARCH

DEPARTMENT MOTHS TO ATTACK PEST Special to THR SUN WELLINGTON, Today. A mass attack against the ragwort menace is promised by the Department of Scientific and Industrial Research for the summer of this year. This, the most comprehensive drive against one of the most serious pests in the country and the trouble of every cattle farmer, is likely to provide farreaching results. For the purpose of providing the necessary ammunition against the ragwort, distributing stations are now being arranged all over the country. The drive against tho pest will be made by use of tyria jacobia, a strik-ingly-marked moth. These moths, black, witii scarlet and red markings, are easy to recognise and have been breeding in the proper surroundings at Cawthron Institute for some time. It was hoped that they would be used this past season, but the scientists have been forced to place them in a period of isolation in order to ensure that no parasites were introduced along with the moths.

Shipments from England have proved to contain a high percentage of parasites, so high that the moths have not been available in the necessary numbers. The year lias been a low one for moths in England, as breeding proceeds in a series of waves, and 1927 having been a “peak year,” we are now in the trough of the wave. The farmers will be supplied with eggs of the moths to place in their patches of ragwort. The range of the moth is •about half a mile, so that it is capable of excellent control. There have now been several generations of it raised in New Zealand, and it was originally hoped that it would breed twice in the year. This is now doubtful. There is no danger to other plants from liberation of tho tyria jacobia.

Plans for liberation are now being finalised, and farmers will receive full instructions when applying at the stations from which the eggs will be had.