Unusual orchid mimics human body odor to attract mosquitoes

A species of orchid has been found to produce a smell like sweaty socks to trick mosquitoes into pollinating it - and it could lead to new ways of protecting humans from the biting insects.

Biologists have discovered the plant, known as the small northern bog orchid, mimics the scent of human body odour to attract the mosquitoes to its flowers.

This makes the tiger mosquitoes - the ravenous Asian species that has invaded much of Europe and North America - into thinking they have found a tasty snack.

A tiger mosquito emerges from a small northern bog orchid with a dollop of pollen on its head. Researchers have found this orchid produces a smell like sweaty socks to trick mosquitoes into pollinating it.

When the insect follows its nose into the plant is emerges with a blob of orange pollen on its head.

The trick cheats the mosquito of a bloody meal but means the orchid’s pollen is carried to the next plant the hungry mosquito visits.

When the insect follows its nose into the plant is emerges with a blob of orange pollen on its head.

The trick cheats the mosquito of a bloody meal but means the orchid’s pollen is carried to the next plant the hungry mosquito visits.

Dr Jeff Riffell, a biologist at the University of Washington who has led the research, said the discovery has allowed his team to identify specific scent molecules that attract the biting mosquitoes and could lead to new ways of protecting people from the insects.

He said: 'These orchids are inconspicuous and blend with the surrounding foliage.

'Despite being relatively cryptic, these orchids attract a diversity of tiger mosquitoes, raising the question of how the orchids attract the mosquitoes.

'We found that the orchids emit a scent comprised of common blood-host volatiles. Smell your armpit - these plants are emitting that same chemical.'

Dr Riffell and his colleagues presented their findings at the annual meeting of the Society of Integrative and Comparative Biology in New Orleans earlier this month.

HOW MOSQUITOES HELP PLANTS

Mosquitoes are normally considered to be poor pollinators for most plants, but a few orchids seem to rely on them to spread their pollen around.

Just 200 of the 3,500 species of mosquitoes on the planet feed on human blood.

Only the females bite when they are developing eggs while males feed exclusively on nectar.