Fensulfothion May Go

Press, Volume CX, Issue 32320, 11 June 1970, Page 1

Fensulfothion May Go

(N Z. Press Association) HAMILTON, June 10. The use of the controversial pesticide fensulfothion for grass-grub control may soon become a thing of the past, according to research results in a paper from a Ruakura entomologist, Mr B. B. Given, at the Ruakura farmers’ conference today.

Mr Given touched only lightly on fensulfothion in his paper on grass-grub control, but spoke of significant results from trials using lowtoxicity materials by subsurface treatment.

Mr Given said he preferred not to name the materials, but he said they were readily available, of low cost and low toxicity.

With the new method of injecting the insecticide beiow I the surface of the ground, trials had produced highly promising results and there was an immediate need to retest previously discarded materials. “This gives reason for considerable optimism for future grass-grub control on areas which can be traversed by lhe equipment,” he said.

“These recent developments in trials are so spectacularly effective that there may be a tendency to consider our problem to be solved,” he said. “I would rather consider these developments to represent the opening of one door to a solution of a large area of the problem,” he said. Mr Given admitted that fensulfothion and another chemical, diazinon, were dangerous to bird, fish and animal life, and that there was a risk of microfaunal imbalance in their use as an insecticide. The new method of treatment had consisted of turf cutting with discs and inserting liquid insecticide directly into the soil at intervals of about 6in. Spraying into the soil with powerful jets had also proved effective, he said.

Other significant research was being carried out with the grass-grub sex attractant, which showed some promise. It had also been found that grass grub would not thrive in lucerne crops, and this suggested that the crop should be more widely used. Mob stocking was another preventive method which had shown some promise at Ruakura, he said. “At present, some 40 scientists and assistants are engaged in research on this pest,” he said. The virtual banning of D.D.T. had led to intensive research on the grass grub, making it the most studied insect in New Zealand.