Date of release: Wednesday, March 1, 2017

Invisible InsectTrillions of 'invisible' insects have been detected migrating over the UK by a special radar invented by scientists at the University of Greenwich's Natural Resources Institute.

The insects aren't actually invisible, but they fly too high to have been recorded in such huge numbers previously.

With the vertical radar, used as part of a decade-long study, scientists were able to detect the biomass (amount of living matter) of these insects that migrate over the UK, which amounts to about 3,200 tonnes per year.

The research could have huge implications when recording economically-important insects for pollination, as well as detecting pests that damage crops.

Dr Don Reynolds, from the Natural Resources Institute (NRI), says that "the mind boggles" over what this could mean for agriculture, particularly in tropical regions.

"The radar was envisaged as providing a powerful means of assessing long-term changes in the biomass and faunal diversity of insects, caused, for example, by environmental perturbations," he says.

"Now, after over ten years of operation, this system has produced a classic data-set of the aggregate movement of insects into and out of southern England.

"If the annual flow of insects over a relatively cool maritime place like the UK is so large, the mind boggles at the enormous numbers which will be on the move in warmer climes, and consequent implications of this for tropical agriculture and ecosystem function."

The radar was invented by Professor Joe Riley and Alan Smith during their time at NRI in the 1990s. The present research was carried out by a multinational group of scientists from Exeter University, Rothamsted Research, the university's Natural Resources Institute, and the Hebrew University and the University of Haifa in Israel.

Senior author Dr Hu, from Nanjing Agricultural University, China, adds: "Many of the insects we studied provide important ecological services which are essential for maintaining healthy ecosystems, such as pollination, predation of crop pests and providing food for insectivorous birds and bats."

NRI press release:

Story by Public Relations

Picture: One of the insect targets of the radar: the hoverfly Episyrphus balteatus, sometimes called the 'Marmalade Hoverfly'.