Insecticides in NZ honey
Aglobal study has found traces of insecticides in New Zealand honey, surprising scientists and puzzling the industry.
Swiss biology Professor Edward Mitchell led a study looking at the pervasiveness throughout the world of neonicotinoids, a class of insecticides, basing it on samples of honey sent from different regions. Four samples of New Zealand honey, three of which were ma¯ nuka, were tested.
All were found to have the insecticides. However, the findings are at odds with testing carried out on behalf of the Ministry for Primary Industries between 2014-16, which showed no traces of neonicotinoids in honey for sale.
Neonicotinoids are the most widely used class of insecticides worldwide. They can either be coated on a seed, providing protection from insects to all parts of the plant as it grows, or sprayed.
Several countries are questioning their use, and France has implemented a ban on the substance.
Mitchell, who works at the University of Neuchatel but is on sabbatical leave at Landcare Research at Lincoln University, said 75 per cent of all the samples worldwide showed traces of the insecticides. Those from the Oceania region had low concentrations and did not represent a health risk for consumers.
The puzzling aspect of the New Zealand testing was that three of the samples were ma¯ nuka, a plant which generally grows in wild scrub or forest areas, remote from where neonicotinoids are used. Mitchell said either the ma¯ nuka was contaminated from spray drift, or else the honey was being blended with another honey, such as clover. Seeds of clover are coated with neonicotinoids before planting.
‘‘We know ma¯ nuka isn’t always pure because producers mix it with something to increase their profit, and they may have mixed it with something which had pesticides in it.’’
Apiculture NZ chief executive Karin Kos said she was surprised at the findings and would need to know more about the samples where they came from and whether they were blended with other honeys that may have had some pesticide residue.
She agreed that native honeys, such as ma¯ nuka, were unlikely to be affected by pesticide use because they were gathered from the wild. ’’MPI monitors pesticides, including neonics, and their published (2013-14) tests showed no detection of neonics in the honey tested. I understand that MPI has undertaken more recent monitoring since then (2015-16 yet to be published) and again there was no detection of neonics,’’ Kos said.
New Zealand’s environmental regulator, the Environmental Protection Authority (EPA) recommends no spraying near hives, budding or flowering crops; and no spraying on crops likely to be visited by bees.
EPA chief scientist Dr Jacqueline Rowarth said the study was an example of the techniques for measurement improving. ‘‘We’re concerned and we’re keeping a close watch but we have very strict regulations over the use of neonicotinoids.’’