RESEARCH ON PASTURE PESTS

Press, Volume CVI, Issue 31161, 10 September 1966, Page 8

RESEARCH ON PASTURE PESTS

About £lOO,OOO a year was now being spent on research into pasture plant pests, Dr. J. M. Hoy, director of the Entomology Division of the Department of Scientific and Industrial Research at Nelson, said last week in Christchurch when he attended a meeting organised by North Canterbury Federated Farmers on the grass grub and porina problem. He indicated that with advantage this amount might be doubled. Dr. Hoy said that his division was spending something like £50,000 a year in this field. In the last 10 years this expenditure would have amounted to about £280,000, and work that had been going on for 30 years would have cost about £400,000. The division had 19 professional officers and 20 technicians and of these eight professional officers and about seven technicians were engaged on pasture pest work, so that about 50 per cent of their total effort was on pasture insects.

As well, at present and for the last six years, they had been supporting a man in Patagonia who was looking for parasites for grass grub and porina and this year 17,000 parasites of the grass grub from this area had been liberated in New Zealand. In the last two years a considerable number of live grubs had been exported to allow work to proceed in a number of places to see if there were pathogens of grass grubs. This material had been sent to France and Germany and some to Trinidad. In Trinidad there were fly parasites which might not survive the journey 'to New Zealand and the material had been sent to meet them half way. Dr. Hoy said he had received advice from Tokyo that Professor Hall, of the University of California at Riverside— Professor Hall had worked in New Zealand—was going to the south of Japan to look at a milky disease of grass grub that might be of use in New Zealand.

Outside his own division in New Zealand Dr. Hoy said that work in the same field was also going on in the chemistry division of the D.5.1.R., the food chemistry division, at Wallaceville research station, the Ruakura

agricultural research centre, Lincoln College, Victoria University and Canterbury University. From discussions that they had had at Victoria University there was some work with rather spectacular possibilities going on there in that Professor Smith had been able to indicate that there might be a chemical possibility of beating resistance of the grass grub to D.D.T. It could be seen, therefore, that the scope of the work was pretty broad. Dr. Hoy noted that both his own department and Cabinet, through the Minister of Science had been sympathetic to this work. It was difficult to see, he said, how the level of research could be stepped up without considerable additional influx of trained minds. The study of the biology and behaviour of the grass grub was something that was lacking at present in the division and it was hoped to make an appointment in the near future for this vital work.

Mr A. R. Dingwall, field superintendent of the Department of Agriculture, said that the research division of the Department of Agriculture was evaluating the organophosphate materials for their effectiveness against porina and grass grub in a series of trials throughout the country, it was studying the effect of grazing management and stocking rates on insect populations and in addition to testing the new chemicals it was studying the times and frequency of applications and also looking into grass grub resistance to D.D.T. While Mr F. C. Allen, of the research division of the Department of Agriculture, suggested that a co-ordinating committee—-he said he had in mind a one man co-ordinating committee —might result in considerably greater progress being made, Dr. Hoy said he felt that as long as there was individual co-operation between workers in this field it was better than having a committee, although he supported the one-man idea. Dr. H. C. Smith, director of the Crop Research Division, nevertheless said he felt that co-ordination between the Department of Agriculture and Department of Scientific and Industrial Research was not perfect and Federated Farmers might help by reminding the National Research Advisory Committee of this and of its responsibilities in this respect.

Dr. R. P. Pottinger, of Lincoln College, suggested that there were three areas where research could be expanded. There was the question of the economic threshhold or entry level for the use of insecticides, there was the field of plant breeding and of insect population dynamics and the things that regulated natural populations. This latter field might need a team of ecologists as there were likely to be variations between regions and soils. Answering questions Dr. Hoy said he believed that twice the present amount could be spent on pasture pest research in New Zealand. If there were the funds to provide buildings and equipment, he said he believed that the staff would follow. He had been encouraged by the number of people overseas who were keen to come to work in New Zealand in this field.