UW News

Jeffrey Riffell


February 8, 2024

Foul fumes pose pollinator problems

Scientists at the University of Washington have discovered that nighttime air pollution — coming primarily from car exhaust and power plant emissions — is responsible for a major drop in nighttime pollinator activity. Nitrate radicals (NO3) in the air degrade the scent chemicals released by a common wildflower, drastically reducing the scent-based cues that its chief pollinators rely on to locate the flower. The findings, published Feb. 9 in Science, are the first to show how nighttime pollution creates a chain of chemical reactions that degrades scent cues, leaving flowers undetectable by smell. The researchers also determined that pollution likely has worldwide impacts on pollination.


February 4, 2022

Mosquitoes are seeing red: Why new findings about their vision could help you hide from these disease vectors

New research led by scientists at the University of Washington indicates that a common mosquito species — after detecting a telltale gas that we exhale — flies toward specific colors, including red, orange, black and cyan. The mosquitoes ignore other colors, such as green, purple, blue and white. The researchers believe these findings help explain how mosquitoes find hosts, since human skin, regardless of overall pigmentation, emits a strong red-orange “signal” to their eyes.


August 11, 2021

‘More pepper, please’: New study analyzes role of scent compounds in the coevolution of bats and pepper plants

An image of a short-tailed fruit bat

A study published Aug. 11 in the Proceedings of the Royal Society B by researchers at the University of Washington and Stony Brook University reports on how bats and pepper plants in Central America have coevolved to help each other survive.


April 22, 2021

UW biology professors Jeffrey Riffell, David Perkel awarded research grants from Human Frontier Science Program

UW biology professors Jeffrey Riffell and David Perkel have received grants from the Human Frontier Science Program.


January 21, 2020

Mosquitoes are drawn to flowers as much as people — and now scientists know why

Despite their reputation as blood-suckers, mosquitoes actually spend most of their time drinking nectar from flowers. Scientists have identified the chemical cues in flowers that stimulate mosquitoes’ sense of smell and draw them in. Their findings show how cues from flowers can stimulate the mosquito brain as much as a warm-blooded host — information that could help develop less toxic repellents and better traps.


July 18, 2019

Scientists discover how the mosquito brain integrates diverse sensory cues to locate a host to bite

A close-up image of a mosquito

A team, led by researchers at the University of Washington, has discovered how the female mosquito brain integrates visual and olfactory signals to identify, track and hone in on a potential host for her next blood meal: After the mosquito’s olfactory system detects certain chemical cues, the mosquito uses her visual system to scan her surroundings for certain shapes and fly toward them, presumably associating those shapes with potential hosts.


January 25, 2018

If you swat mosquitoes, they may learn to avoid your scent

A tethered, flying Aedes aegypti mosquito.

In a published Jan. 25 in Current Biology, University of Washington researchers report that mosquitoes can learn to associate a particular odor with an unpleasant mechanical shock akin to being swatted. As a result, they’ll avoid that scent the next time.


July 16, 2015

UW researchers show that the mosquito smells, before it sees, a bloody feast

A female mosquito feeding on a host.

A team of biologists from the University of Washington and the California Institute of Technology has cracked the cues mosquitoes use to find us.


June 26, 2014

Foul fumes derail dinner for hungry moths

moth with flower and exhaust pipe

New research on how pollinators find flowers when background odors are strong shows that both natural plant odors and human sources of pollution can conceal the scent of sought-after flowers.


December 6, 2012

Moths wired two ways to take advantage of floral potluck

Moths are able to enjoy a pollinator’s buffet of flowers because of two distinct “channels” in their brains, scientists have discovered.