Scientists turn flower fragrance into a mosquito killer

By exploiting mosquitoes’ attraction to flowers, an international team of researchers has designed a new strain of mosquito Metarhizium A mushroom that releases a sweet scent that resembles real flowers. The modified fungus attracts, infects and eventually kills insects.

The scientists were inspired by natural fungi that emit a gentle chemical known as longifolin, which they discovered can attract mosquitoes. Building on this idea, they created a fungus that acts as a pest-killing perfume, offering a promising tool against malaria, dengue, and other deadly diseases that are becoming increasingly resistant to chemical insecticides. Their findings were published in Nature Microbiology On October 24, 2025.

How do “scented” mushrooms work?

“Mosquitoes need flowers because they provide nectar, which is an important source of food for them, and they are attracted to flowers by their scent,” explained paper co-author Raymond St. Leger, Distinguished University Professor of Entomology at the University of Maryland. “After noticing that some species of fungi can trick mosquitoes into thinking they are flowers, we realized we could enhance attraction by engineering fungi to produce more longfoulin, a sweet-smelling compound very common in nature. Before this study, longfoulin was not known to attract mosquitoes. We are letting nature give us a hint to tell us what works against mosquitoes.”

According to St. Leger, the floral-scented mushroom provides an easy and accessible way to control mosquito populations. The spores can simply be placed in containers indoors or outdoors, where they gradually release longifolin over several months. When mosquitoes come into contact with the fungus, they become infected and die within a few days. In laboratory tests, the fungus killed 90 to 100 percent of mosquitoes, even in environments filled with competing odors from humans and real flowers. Despite its potency, the fungus is completely harmless to humans.

Safe, targeted and environmentally friendly

“The fungus is completely harmless to humans, as longifolene is already commonly used in perfumes and has a long safety record,” St. Leger said. “This makes it safer than many chemical insecticides. We’ve also designed the fungi and their containers to specifically target mosquitoes rather than any other insects, and longifolin degrades naturally in the environment.”

Additionally, unlike chemical alternatives to which mosquitoes gradually become resistant, it may be nearly impossible for mosquitoes to overcome or avoid this biological approach.

“If mosquitoes evolve to avoid longifolene, it could mean that they will stop responding to flowers,” St Leger explained. “But they need flowers as a food source to survive, so it will be interesting to see how they can avoid the fungi while still being attracted to the flowers they need. This hurdle will be very difficult for them to overcome, and we have the option of engineering the fungus to produce additional floral scents if they evolve to avoid longifolin specifically.”

Affordable and scalable global capabilities

What makes this new fungal technology particularly promising is how practical and affordable it is to produce. Other forms of Metarhizium They are already commonly grown around the world using cheap materials such as chicken litter, rice hulls, and wheat residue that are readily available after harvest. The affordability and simplicity of mushrooms could be key to reducing mosquito disease-related deaths in many parts of the world, especially in poor countries in the global South.

Finding new weapons that are effective against mosquitoes may be more important than ever. St. Leger warns that mosquito-borne diseases currently limited to the tropics could threaten new targets in the future, including the United States. As global temperatures rise and weather becomes more unpredictable, disease-carrying mosquitoes are beginning to spread to new areas outside their usual habitats.

“Mosquitoes love the many ways we are changing our world,” St. Leger said. “For now, we hope to use these methods in Africa, Asia and South America. But one day, we may need them for ourselves.”

Next steps in combating mosquito-borne diseases

St. Leger and his colleagues are now testing the mushroom in larger outdoor trials to prepare it for regulatory review.

“It’s not as if we’re necessarily going to find a magic solution to control mosquitoes everywhere, but we’re trying to develop a very diverse and flexible set of tools that people around the world can use and choose from,” St. Leger said. “Different people will find that different methods work best for their particular condition and the mosquitoes they are dealing with. Ultimately, our goal is to give people as many options as possible to save lives.”