Nav: Home

Migratory hoverflies 'key' as many insects decline

June 13, 2019

Migratory hoverflies are "key" to pollination and controlling crop pests amid the decline of many other insect species, new research shows.

University of Exeter scientists studied the movements of migratory hoverflies and were surprised to find up to four billion migrate to and from Britain each year.

The study shows these numbers have been relatively stable over the last decade, and such abundance means migratory hoverflies pollinate many billions of flowers and produce larvae that eat up to ten trillion aphids.

Recent research has suggested more than 40% of insect species worldwide are "threatened with extinction", creating a major threat to "ecosystem services" (benefits to humans from the natural environment, such as pollination of crops).

"The number of migrating hoverflies coming and going over Britain was much higher than we had expected," said Dr Karl Wotton, Royal Society research fellow at the University of Exeter.

"They are widely considered to be the second most important pollinators, after bees.

"They are especially important pollinators of wildflowers, soft fruits and brassica crops, and their larvae prey on various species of aphids - which are the key crop pest in Europe.

"This dual role makes them uniquely beneficial to humans."

Migrating hoverflies arrive in Britain in spring and, with a month-long life cycle, those that leave are descendants of the spring arrivals.

"We are net exporters of hoverflies," said Dr Jason Chapman, of the Centre for Ecology and Conservation on the University of Exeter's Penryn Campus in Cornwall.

"Each female can lay up to 400 eggs and, though many die as eggs or larvae, the departing population in autumn is larger than that arriving in spring.

"As well as their vital pollinating and aphid-eating roles, migrating hoverflies provide food for a range of predators including birds."

The study, supported by colleagues at Nanjing Agricultural University, Rothamsted Research, the University of Greenwich and the Max Planck Institute, used radar data on insects flying between 150m and 1km above the ground.

The hoverflies wait for favourable winds before migrating between Britain and mainland Europe.

Dr Chapman added: "Migrating insects are generally bucking the trend of decline that we're seeing with many other insects.

"Their mobility is probably a key part of this, as it allows them to move on to find the best habitats.

"Hoverflies are also generalists - the adults feed on many kinds of pollen and the larvae eat many aphid species.

"Considering that many beneficial insects are seriously declining, our results demonstrate that migrant hoverflies are key to maintaining essential ecosystem services."
-end-
The study used data on the marmalade hoverfly and the vagrant hoverfly (collectively termed "migrant hoverflies") gathered by radar equipment at Rothamsted Research, funded by the Biotechnology and Biological Sciences Research Council (BBSRC).

The paper, published in the journal Current Biology, is entitled: "Mass seasonal migrations of hoverflies provide extensive pollination and crop protection services."

University of Exeter

Related Pollination Articles:

To bee, or not to bee, a question for almond growers
The study co-authored by CTAHR's Ethel Villalobos suggests that 'Independence' almonds, like many plants that are self-compatible, still performed better when bees were assisting in pollination.
Pollination is better in cities than in the countryside
Flowering plants are better pollinated in urban than in rural areas.
Earliest evidence of insect-angiosperm pollination found in Cretaceous Burmese amber
Most of our food is from angiosperms, while more than 90% of angiosperms require insect pollination - making this pollination method hugely important.
New fossil pushes back physical evidence of insect pollination to 99 million years ago
A study co-led by researchers at Indiana University and the Chinese Academy of Sciences has pushed back the first-known physical evidence of insect flower pollination to 99 million years ago, during the mid-Cretaceous period.
Global model reveals a future without nature's crucial contributions to humanity
A new model that captures nature's contributions to human wellbeing and compares them to peoples' future needs shows that, within the next thirty years, as many five billion people could face water and food insecurity -- particularly in Africa and South Asia.
New tool improves beekeepers' overwintering odds and bottom line
A new tool from the Agricultural Research Service (ARS) can predict the odds that honey bee colonies overwintered in cold storage will be large enough to rent for almond pollination in February.
Bees required to create an excellent blueberry crop
Getting an excellent rabbiteye blueberry harvest requires helpful pollinators -- particularly native southeastern blueberry bees -- although growers can bring in managed honey bees to do the job, according to Agricultural Research Service (ARS) scientists.
Migratory hoverflies 'key' as many insects decline
Migratory hoverflies are 'key' to pollination and controlling crop pests amid the decline of many other insect species, new research shows.
Close relatives can coexist: two flower species show us how
Scientists have discovered how two closely-related species of Asiatic dayflower can coexist in the wild despite their competitive relationship.
Interplay of pollinators and pests influences plant evolution
Brassica rapa plants pollinated by bumblebees evolve more attractive flowers.
More Pollination News and Pollination Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Meditations on Loneliness
Original broadcast date: April 24, 2020. We're a social species now living in isolation. But loneliness was a problem well before this era of social distancing. This hour, TED speakers explore how we can live and make peace with loneliness. Guests on the show include author and illustrator Jonny Sun, psychologist Susan Pinker, architect Grace Kim, and writer Suleika Jaouad.
Now Playing: Science for the People

#565 The Great Wide Indoors
We're all spending a bit more time indoors this summer than we probably figured. But did you ever stop to think about why the places we live and work as designed the way they are? And how they could be designed better? We're talking with Emily Anthes about her new book "The Great Indoors: The Surprising Science of how Buildings Shape our Behavior, Health and Happiness".
Now Playing: Radiolab

The Third. A TED Talk.
Jad gives a TED talk about his life as a journalist and how Radiolab has evolved over the years. Here's how TED described it:How do you end a story? Host of Radiolab Jad Abumrad tells how his search for an answer led him home to the mountains of Tennessee, where he met an unexpected teacher: Dolly Parton.Jad Nicholas Abumrad is a Lebanese-American radio host, composer and producer. He is the founder of the syndicated public radio program Radiolab, which is broadcast on over 600 radio stations nationwide and is downloaded more than 120 million times a year as a podcast. He also created More Perfect, a podcast that tells the stories behind the Supreme Court's most famous decisions. And most recently, Dolly Parton's America, a nine-episode podcast exploring the life and times of the iconic country music star. Abumrad has received three Peabody Awards and was named a MacArthur Fellow in 2011.