WAR ON RAGWORT

King Country Chronicle, Volume XXIX, Issue 4762, 22 October 1935, Page 6

WAR ON RAGWORT

SUPPLIES OF SEED-FLY TO BE LIBERATED Permission has been given by the Minister of Agriculture, Hon. C. E. Macmillan, to Dr. Miller, chief of the entomological department of the Cawthorn Institute, to liberate supplies of the ragwort seed Ay (Pegohylemyia jacobaeae). Exhaustive tests have been carried out with plants other than its normal host to ensure that the insect is not likely to become injurious to economic plants. Ragwort belongs to the family Compoisitae, a group of plants among which there are no cultivated crops, with the exception of lettuce, artichokes and sunflower, and the com--posites of a flower garden. Tests with Pegohylemyia have been made on cineraria, calendula and lettuce, and on the following weeds: Groundsel, ox eye daisy, common daisy, dandelion'-and cat’s ear. The results in all cases were negative. The fly is readily attracted to ragwort in the floral disc of which it lays its eggs, the larvae from which (Dr. Miller says) destroys 100 per cent, of the seeds in each infested head. In view of the habits of the fly in Great Britain, where it confines its attention to ragwort, and of the results of the tests made at Cawthorn Institute, Dr. Miller has given it as his opinion that Pegohylemyia is a perfectly safe insect to liberate in the field.

Referring to the subject recently, the Minister remarked that he hoped it would prove effective in practice as it had done under controlled conditions. “But,” he added, “I would not advise any farmer to relax his efforts with sodium chlorate yet.”