Fumes Keep Moths From Finding Flowers, Study Discovers

Wednesday, July 2, 2014

Car and truck exhaust fumes that foul the air for humans also cause problems for pollinators.

In new research on how pollinators find flowers when background odors are strong, University of Washington and University of Arizona researchers have found that both natural plant odors and human sources of pollution can conceal the scent of sought-after flowers.

When the calories from one feeding off a flower fuels only 15 minutes of flight, as is the case with the tobacco hornworm moth studied, being misled costs a pollinator energy and time.

"Local vegetation can mask the scent of flowers because the background scents activate the same moth olfactory channels as floral scents," said Jeffrey Riffell, assistant professor of biology at UW. "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."

Riffell is lead author of a paper on the subject in the June 27 issue of Science.

"This is the first significant example of powerful mass spectrometry used to provide information to explain an olfactory environment," said Leif Abrell, a scientist in the UA Arizona Laboratory for Emerging Contaminants and associate research scientist in the Department of Soil, Water and Environmental Sciences with a joint appointment in the Department of Chemistry and Biochemistry, who studied floral odor plumes in a creosote bush habitat in the Santa Rita Experimental Range southeast of Tucson, Arizona.

The scientists used a chemical detection device called a proton-transfer reaction mass spectrometer to, for the first time, track the odors emitted by flowers in the wild just as moths might encounter them. With wingspans of 4 inches, adult Manduca sexta moths can travel up to 80 miles in an evening looking for food and mates.

Read the rest of this June 30, 2014 UANews article at the link below.

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