Bugs devour rapeseed crop in Britain as EU ban on pesticide to save bees comes into force
Peter Kendall surveys his crop of oilseed rape. At this time of year, he should usually be looking at healthy green cotyledons (young shoots), but the leaves are full of holes.
The driest September on record has meant a plague of flea beetle. The pest is normally controlled by coating the seeds in a systemic pesticide called neonicotinoid.
The chemical, related to nicotine, is absorbed by the plant as it grows, making it resistant to bugs and viruses.
The trouble is that the neurotoxins stay in the plant when it flowers and scientists are concerned that later in the season this could be taken up by bees and other foraging insects.
Last year three neonicotinoid seed treatments used by British farmers on autumn sown oilseed rape were banned by Brussels because of the risk to bees. This is the first year the ban has come into force, and farmers say they are struggling.
Kendall, chairman of the Agriculture and Horticulture Development Board (AHDB), has already sprayed his crop in Bedfordshire three times this year with an alternative insecticide, before giving up, replanting and spraying again. He believes the pyrethroids he is using are worse for insects in the soil now, like ground-nesting bees and scarab beetles.
“There is a strong feeling among farmers that we are worse off and the environment is worse off,” he says.
Later in the season, if oilseed rape is vulnerable to another problem, turnip yellows virus spread by the peach potato aphid, then Kendall will have to spray again.
A crop that would usually have one seed treatment followed by a maximum two sprays, could have at least five. This comes at an extremely busy time of year for farmers and at a cost in machinery and man hours, as well as buying the pyrethroids.
Kendall, former president of the National Farmers Union, is expecting his crop to be down by around 30% and says the 700,000 hectare (17.2m acre) UK crop to be down by a quarter at a cost of millions – although it will not affect the price of food because oilseed rape is traded as a global commodity.
In some parts of the country, the oilseed rape crop is so badly infected with flea beetle, the Department for the Environment Food and Rural Affairs (Defra) approved emergency use for a neonicotinoid spray. Although it may be slightly weaker than the banned neonicotinoid, it is still a systemic pesticide taken up by the plant and surrounding soil.
Kendall says this is bad for “beneficial insects” as it means the chemical is being spread across the field, rather than only going into the plants that need protecting.
“The jury is still out on whether it did more harm than good banning neonicotinoids,” he says.
However, some farmers insist that it is possible to grow oilseed rape without neonicotinoids.
Peter Lundgren, a Lincolnshire farmer, gave up using neonicotinoids before the ban because of concern for bees and other insects.
He prefers to use pyrethroid spray because it is only used against pests in bad years, rather than an annual seed treatment that could harm bees in the summer, and it breaks down faster in the soil.
He also advocates conventional plant breeding and “companion planting” to encourage predator insects that can help keep down pests.
“This bleating by farmers at the moment is a totally counter productive PR disaster. It is not going to change anything,” he says.
“The public will never accept that a financial loss for oilseed rape crops is worth the loss of bees. We have to get on and manage this problem in the short-term and we have to get government and the research institutes to find a solution in the long-term.”
Dave Goulson, professor of biology at the University of Suffolk, points out that the banned neonicotinoids are still in the plant when bees come to forage, whereas the sprays being used by most farmers now break down in the soil.
He says the risk to bees of using the banned neonicotinoids is too great.
“You have to sympathise with farmers who have lost their crop. On the other hand you have to weigh up the damage of neonicotinoids over many years,” he says. “Doesn’t destroying the environment and the health of bees have greater ramifications than the loss of one crop?”