WAR ON RAGWORT

Poverty Bay Herald, Volume LV, Issue 17238, 19 April 1930, Page 16

WAR ON RAGWORT

LIBERATION OF MOTHS NEXT SEASON'S PLANS When ragwort makes it appearance next spring the young plants will be attacked by cinnabar moths which the Department of Scientific and Industrial Research is arranging to have liberated in those parts of the Dominion where the weed lias a hold. Ragwort is perhaps the greatest pest the farmer lias to contend with, and' the forthcoming drive against it will be one of the .most comprehensive of iis kind ever undertaken in this country.

Groat care is taken to ensure that importations of tyria jacobea (Cinnabar moths) are free from parasites. They are at first liberated in a special wire insectry at the €awthron Institute, in which there are a number of ragwort plants encased by means of gauze. By this means the parasites attacking the cinnabar moth are eliminated and so are not liberated with subsequent' issues of the moth. Last season the consignments were heavily parasiteised, and in one lot of 19,000 pupae 127!) were found to be so affected. DISTRIBUTION OF EGGS

The moths emerging from the pupae deposit eggs upon the leaves of the ragwort plants enclosed i» the insectry. During the past season some 190,000 eggs have been distributed as fol-

lows.—Hamilton, 4280; To Puke, 0318; Kotoruo, 1)805.; Te Kuiti, 17.7(H); West Coast, 8440; Dunedin, 19,350; Inverciirgill, 0530; Gore, 7245; Blenheim, olCo; Auckland, 2890; Hicks Bay, 2485"; Tokoma.ru Bay, 4390; New Plymouth, 1975; Palmerston North, 4690; Masteriim, 1830; llawera, 2930; Gisborne, lifiOo: Wakefield, 2,14."); Putaruru, 1845, NEXT SKAS-ON'S PLANS The season for distribution of the eggs has now past, and numerous inquiries for supplies have had to be declined pending the appearance of the fresh growth of ragwort in the coming spring months, when an organisation will •arrange for wholesale distribution. It is stated that unless something untoward happens there uliould be abundant supplies of eggs available for almost every ragwort infested area in the Dominion. Distributing stationsthroughout the country are now being arranged for, together with plans for liberation. Pull instructions will be issued to fanners who ajiply for eggs."* Owing to the pest being so widely scattered i! will lie necessary (it is stated) for fanners to assist the organisation by arranging for distribution of" moths to the various patches where farms are affected by ragwort. The moth flies only a short distance: from where it is established, and soi that it may attack promptly and be-J fore it is attacked itself by any field| parasites it is desirable that it hoi spread as rapidly as possible. j

It is not known whether the moths effectually eradicate ragwort, but it is recognised that they are a valuable ally to the farmer in other steps lie may be taking to .minimise the spread of the weed. The tyria jaeobea is a striking, easily-recognised black moth with scarlet and red markings.