One can imagine what went through the minds of a group of budding bug hunters when they were told to count some of the 150 million creepy crawlies that surrounded them.

One can imagine what went through the minds of a group of budding bug hunters when they were told to count some of the 150 million creepy crawlies that surrounded them.

But the Paston College biology students relished the chance to catch and categorise as many insects as they could as part of an innovative scheme to see if beetles, flies and bugs are dwindling in number.

Some species of common insect have declined by a third.

Friday's insect count at Carr Farm in Ormesby St Margaret, near Yarmouth, was also an opportunity to encourage youngsters to sample agricultural life.

The group of 24 A-level students form the North Walsham college was soon surrounded by a motley and unusual collection of insects as they swept through the farm's grassland and sugar beet crop.

Species found included shield bugs, frog hoppers and robber flies.

And they were stunned to discover a species of ant that farms aphids for the waste they produce.

Students were helped in their hunt by the president of the Royal Entomological Society, Professor Lin Field, who said that there were about 150 million insects per square mile of farmland.

The bug count was organised as part of National Insect Week, which aims to dispel some of the common conceptions about the six-legged creatures.

Prof Field said: “If you ask children about insects they think they are horrible and want to squash them. But in fact insects are vital as without them all eco-systems would collapse.

“However we do not know enough about insect numbers and what is happening to them.

“That is why events like today are very important.”

Future counts at Carr Farm could unearth bizarre forms of foreign insect, such as the Saxon wasp and the harlequin ladybird, as global climate change causes insects to move.

Farm owner Richard Hirst was glad to have the opportunity to show that farmland still has a rich and diverse collection of insects and he was even glad that some forms of predatory bugs were increasing in number.

Mr Hirst said: “Every time I have to open a can of pesticide it costs money. So if insects are being eaten by other insects it makes our lives a bit easier.”

The Royal Entomological Society will collate the data from the count, which was one of several being carried out across the country for National Insect Week.

Friday's event was also part of the school and farm wildlife programme and was funded by the Clan Trust, which seeks to promote the countryside.