RAGWORT SEED-FLY

Bay of Plenty Times, Volume LXVII, Issue 12470, 3 October 1938, Page 8

RAGWORT SEED-FLY

EFFECTIVE WORK AT TIRAU

A visitor to-Tauranga is Mr. A. A. Riggir, of Tirau, who called in at the Bay of Plenty Times Office this morning and had a few words to say on the effective work of the ragwort seed-fly, which was first liberated on his farm in Februrary, 19 38. This property comprises six hundred acres, and Mr. Riggir says the seed-fly has been a great factor in checking the weed. The fly is the size of a housefly and after the female lays a;singlo egg in the flower, the grub develops and feeds on the seed for a period of I seven weeks, and in that time the i seed is completely devoured, every ! ragwort flower head examined, showing one hundred per cent, destruction. The grub then drops to the ground and burrows in, sometimes to | a depth of six inches. Here the grub develops into a fly and thus completes ■ the cycle. The fly has a life of seven weeks, and during that time iays, approximately, two hundred eggs—only one being deposited on each flower.

Mr. Riggir is emphatic in declaring that effective work has been accomplished by the seed-fly, and says it should make its appearance in about a month, synchronising with the period when the ragwort is ready co burst into bloom.. He is hopeful that in time the seed-fly will be sufficiently numerous to enable landowners to cope with the ragwort menace.