Breeding beetles could damage harvest
supplies for bread manufacturers if growers fail to implement
proper post-harvest procedures.
The UK's Home Grown Cereals Authority has set guidelines for farmers after fears that this summer's heatwave could give rise to an insect infestation.
Recent increases in the price of flour combined with a reduction in global wheat supplies have made for an unsteady baking industry that would be further damaged by a drop in grain quality caused by the beetles.
This year's hot summer, when temperatures reached up to 35 degrees in the UK, has produced crops with low moisture content, eliminating the need for the standard drying and cooling processes that delay insect development.
But the grain beetle remains a serious threat as it carries out its lifecycle at 30 degrees - the temperature of most crops when they are harvested - and can complete a generation within 14 days unlike most insects which can take up to a month to develop.
David Armitage, a researcher at the London-based Central Science Laboratory which is collaborating with the HGCA, told bakeryandsnacks.com that up to 20 per cent of the harvest can be rejected in a warm year, such as this one, due to damage caused by insects.
To safeguard this summer's crop, the CSL and HGCA are advising farmers to use adequate cooling methods such as fans and thermostats to bring the temperature of the crop down to below 20 degrees to ensure the beetle stops breeding.
In the past, the risk of insect infestation was minimised by reliance on pesticides but now the HGCA are seeking to promote the natural method of temperature control.
Armitage said: "We have only recently weaned farmers away from pesticides and now we need a more strict cooling regime where fans are pivotal."
And with climate change sending temperatures soaring in the next decade, the situation could worsen.
A project funded by the UK's department of food and rural affairs (DEFRA) is currently underway to examine how early harvests and warm summers will affect cooling needs and storage practices.
This year, HGCA are advising farmers to cool grain as soon as it is brought into store and reduce the temperature to 15 degrees within a fortnight, dropping to 10 degrees soon after in an effort to achieve the desired minimum of 5 degrees by Christmas.
