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:

Heated rivalries for pollinators among arctic plants
Insect pollination is as important to Arctic plants as it is to plants further south.
Mutant tomato helps to crack the secrets of fruiting
Researchers from the University of Tsukuba have found that fruit development in tomatoes rewires their central metabolism.
Does city life make bumblebees larger?
Does urbanisation drive bumblebee evolution? A new study by Martin Luther University Halle-Wittenberg (MLU) and the German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig provides an initial indication of this.
Land-use change disrupts wild plant pollination on a global scale
Human changes to the environment have been linked to widespread pollinator declines.
Bees' buzz is more powerful for pollination, than for defence or flight
Buzzing by bees during flower pollination is significantly more powerful than that used for defense or flight, according to a new study from experts at the University of Stirling.
Decline of bees, other pollinators threatens US crop yields
Crop yields for apples, cherries and blueberries across the United States are being reduced by a lack of pollinators, according to Rutgers-led research, the most comprehensive study of its kind to date.
Soap bubbles pollinated a pear orchard without damaging delicate flowers
Soap bubbles facilitated the pollination of a pear orchard by delivering pollen grains to targeted flowers, demonstrating that this whimsical technique can successfully pollinate fruit-bearing plants.
Agroforestry is 'win win' for bees and crops, study shows
Agroforestry has long been suggested as a solution to halt the decline of pollinators, yet observational studies in temperate climates have been virtually non-existent.
Bees? Please. These plants are putting ants to work
This is the first plant species in the world found to have adapted traits that enables a mutually beneficial relationship with ants.
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.
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

Debbie Millman: Designing Our Lives
From prehistoric cave art to today's social media feeds, to design is to be human. This hour, designer Debbie Millman guides us through a world made and remade–and helps us design our own paths.
Now Playing: Science for the People

#574 State of the Heart
This week we focus on heart disease, heart failure, what blood pressure is and why it's bad when it's high. Host Rachelle Saunders talks with physician, clinical researcher, and writer Haider Warraich about his book "State of the Heart: Exploring the History, Science, and Future of Cardiac Disease" and the ails of our hearts.
Now Playing: Radiolab

Insomnia Line
Coronasomnia is a not-so-surprising side-effect of the global pandemic. More and more of us are having trouble falling asleep. We wanted to find a way to get inside that nighttime world, to see why people are awake and what they are thinking about. So what'd Radiolab decide to do?  Open up the phone lines and talk to you. We created an insomnia hotline and on this week's experimental episode, we stayed up all night, taking hundreds of calls, spilling secrets, and at long last, watching the sunrise peek through.   This episode was produced by Lulu Miller with Rachael Cusick, Tracie Hunte, Tobin Low, Sarah Qari, Molly Webster, Pat Walters, Shima Oliaee, and Jonny Moens. Want more Radiolab in your life? Sign up for our newsletter! We share our latest favorites: articles, tv shows, funny Youtube videos, chocolate chip cookie recipes, and more. Support Radiolab by becoming a member today at Radiolab.org/donate.