CONTROL OF MANUKA

Press, Volume C, Issue 29554, 1 July 1961, Page 6

CONTROL OF MANUKA

Bug Fails In North I The mealy bug which a I few years ago destroyed I large areas of manuka in the Nor'h Island as well as the South Island has let the northerners down rather badly. At the Massey College sheepfarmers’ conference this week Mr E M. Small, of the ' college staff, in the course of a paper on problems of undeveloped east coast (Wairarapa) hill country, described the manuka as the | arch criminal weed of hill ! pastures and recalled how since the bug had been attacked .by a parasitic fungus ia few years ago the recovery of infested plants in the North Island had been as spectacular as the wave of destruction which preceded it. What had happened to the bug, someone asked from the floor of the meeting. Had it also gone off to the cities like the farm labour? Mr J. M. Hoy, an officer of the Entomology Division of the Department of Scientific and Industrial Research who was formerly stationed in Canterbury, said that the insect had been introduced from Australia accidentally about 30 years ago and it must have apparently brought the fungus parasite in on it. In the dry areas of the South Island the bug had kept ahead of the fungus. In the North Island where it was introduced in 1946 it had controlled large areas of manuka by 1956 but by that time the fungus was on top. Mr Hoy did not hold out much hope for it successfully controlling manuka under existing conditions in the north, but he said the position remained in parts of the South Island that manuka had been virtually eliminated. On the question of some other form of biological control in the North Island, Mr Hoy said that manuka was not a noxious weed. It I definitely had a place in (countering soil erosion and (as a nurse crop for indigenous forests and before any work could be done on other forms of biological control a decision would have to be obtained as to whether manuka was a weed in all situations. From a technical point of view further work on biological control of manuka was quite practicable, he said.