‘Huge’ insect numbers in green headlands

Monitoring of highly productive crop fields in East Anglia last year has identified a ‘huge’ number of insects and a ‘vast’ array of biodiversity, its organisers say.

On Ipswich farmer Geoffrey Mayhew’s farm, between 41 and 55 different species were found in each of the Green Headlands looked at.

The Green Headland initiative, run by agrochemicals and seeds firm Syngenta and supermarket giant Asda, involves planting field headlands around potato and vegetable crops with a flower-rich green manure mix to provide pollen and nectar sources for insects, and give fertility-building soil protection.

It is run in association with grower supply group, IPL, and specialist seed suppliers, Kings.

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The companies behind it say potato and vegetable growers are providing “hugely valuable habitat” to increasing populations of solitary bees.

The Squat Furrow Bee and a Five Banded Digger Wasp, which is nationally rare and a key target for action to enhance biodiversity, were among the finds on Geoffrey Mayhew’s farm near Erwarton, which scooped a Syngenta Operation Pollinator Green Headlands Biodiversity Award 2018.

The wasp can help control crop pests, by hunting and collecting damaging weevils, which it buries and uses as a food source for its young.

It was one of a large number of predatory insects identified in the Green Headland margins, which can beneficially help to reduce pest pressure on crops.

Independent ecologist, Paul Lee, assessed more than 36,000 invertebrates, collected from sweep netting on six farms on two occasions over the summer 2018.

He found that some Green Headland margins contained up to 55 different species.

The survey identified 199 different insect species overall, with beetles and bugs dominated the mixtures, he said.

Some solitary bee species have been increasing in both number and range across the UK over the past decade, benefiting from the trend to warmer temperatures.

“Last year’s record temperatures and prolonged dry conditions were particularly favourable, with the numbers seen increase accordingly,” he said.

Solitary bees are typically far more efficient as pollinators, compared to honey bees, and the hairy bodies of some species can transfer dry pollen between flowers more effectively.

The Squat Furrow Bee, classified as nationally scarce, has been doing well, moving further north and expanding its range, and was found on half of the assessed farms across the region.

Mr Mayhew said the mix had brought a range of benefits to the farm. These included plant biomass and rooting to protect and enhance soil structure on the headlands. It had also captured nutrients to benefit the soil for his crops.

“Environmentally it delivers a real positive boost for the farm and, since we are growing the mix on previously uncropped headland, there is no loss in productivity from then field,” he said.

“It’s also a great attraction for visitors to the farm.

“We could now look to integrate each year’s Green Headlands with other environmental features on the farm, as well as the initiatives of other farmers in the area, to coordinate a truly exceptional and huge ecological resource for the Suffolk area, within a highly productive farming landscape.”