The climate and the flight of bees

There are things we take for granted , as if they always existed and were meant to last forever. The blue of the sky, the waves crashing on the rocks, the bees buzzing flying from flower to flower . Yet even our apparent certainties begin to creak due to climate upheavals.

The researchers of the Imperial College of London have dedicated themselves to bees and bumblebees , publishing their findings in the scientific journal Functional Ecology . As the external temperature increases , starting from a minimum of 12 degrees centigrade and reaching a peak of 25-27, both the motivation of insects to fly and the duration of their journey increase . Once this threshold is exceeded, however, both begin to decline .

This is good news, but only for countries in the northernmost latitudes. In much of the planet , 27 degrees centigrade are abundantly exceeded for several months a year, as we learned to our expense this summer with the 48.8 degrees recorded in Syracuse. If so, there is reason to be concerned as the flight of bees is linked to pollination , an invaluable ecosystem service.

The effect of heat and cold waves

There is more. ” More extreme weather events , such as unprecedented frost or heat waves such as we have seen in recent years, could regularly push temperatures beyond the range that allows some species of bumblebees to fly comfortably,” declares the first author of the paper, Daniel Kenna .

“These risks are particularly relevant for pollinators from resident colonies , such as bumblebees , which cannot change position over the course of the season if conditions are no longer favorable. Potentially these risks give us an additional explanation as to why losses have been observed at the southern limits of the species’ range.

Pollination is at stake. And not only

There are several valid reasons to devote all this attention to insects. Very few plant species are able to pollinate themselves ; all the others need the work of bees, bumblebees, but also bats, moths, wasps. It is estimated that around 5-8% of global food production is directly attributable to pollinating animals . Without them , apples , oranges , strawberries , apricots , beans , chamomile , tomatoes , peppers and dozens of other foods would disappear from our tables.

The study of the Imperial College therefore allows to make estimates on this crucial function, but not only. ” How different flying insects respond to rising temperatures could also influence the spread of insect-borne diseases and agricultural pest outbreaks that threaten food systems ,” said Richard Grill, also author of the research.

” Applying our experimental setup and results to other species can help us understand future trends in insects that are important for service delivery management or pest control methods .”