Car Exhausts Mislead Moths, Study

Car fumes and other vegetation scents are distracting moths from finding their favourite flowers, a new study suggests.

University of Washington researchers and colleagues have found that strong odors prevent Manduca sexta moths from pollinating flowers such as Sacred Datura or Datura wrightii. Nectar from a flower energises a moth for only about 15 minutes. Losing a track of next feeding spot might be deadly for the organism.

"Local vegetation can mask the scent of flowers because the background scents activate the same moth olfactory channels as floral scents," said Jeffrey Riffell, UW assistant professor of biology, according to a news release. "Plus the chemicals in these scents are similar to those emitted from exhaust engines and we found that pollutant concentrations equivalent to urban environments can decrease the ability of pollinators to find flowers."

Researchers used proton-transfer reaction mass spectrometer to track scents emitted by flowers in the wild. The team found that scents produced by other flowers and car exhausts masked the scent of flowers like Sacred Datura, or Datura wrightii, which are moths' favourite plants.

Moths' sense of smell is comparable to that of dogs. Experiments conducted in lab also showed that background scents misled moths into choosing wrong flowers.

"We'd assumed that the moth's ability to smell the flowers would be more specific. Instead, other volatiles also activated those same olfactory pathways," Riffell said.

In the next part of the study, researchers want to explore whether urban pollutants confuse other pollinators such as honeybees.

The study shows that odors from cars and trucks could be distracting insects that play a vital role in pollination, Alex Smith, a biologist at the University of Guelph in Ontario told The Verge.

The study is funded by University of Washington is published in the journal Science.