Nearly 700 million people suffer from mosquito-borne diseases — such as malaria, West Nile, Zika and dengue fever — each year, resulting in more than 1 million deaths. Increasingly, many species of mosquitoes have become resistant to the popular pyrethroid-based insecticides. Today, researchers report a new class of mosquito repellents based on naturally occurring compounds that are effective in repelling mosquitoes with potentially fewer environmental side effects than existing repellents.
The scientists will present their research today at the 256th National Meeting & Exposition of the American Chemical Society (ACS). ACS, the world’s largest scientific society, is holding the meeting here through Thursday. It features more than 10,000 presentations on a wide range of science topics.
“Our new repellents are based on how nature already works,” Joel R. Coats, Ph.D., says. “For example, citronella, a spatial repellent that comes from lemongrass, contains naturally occurring essential oils that have been used for centuries to repel mosquitoes. But citronella doesn’t last long and blows away easily. Our new, next-generation spatial repellents are variations of natural products that are longer-lasting and have greater repellency.”
Coats and graduate students James S. Klimavicz and Caleb L. Corona at Iowa State University in Ames have been synthesizing and testing hundreds of compounds against mosquitoes. They knew that sesquiterpenoids, which are found in many plants, are effective insect repellents, but these large molecules are difficult to isolate from plants and hard to make and purify in the laboratory.
Because of the challenges of synthesizing sesquiterpenoids, Coats’ team designed their repellents using smaller, less complex, easily obtainable molecules — monoterpenoids and phenylpropanoid alcohols with known, short-term repellent activities against insects. By modifying these compounds chemically, they produced new potential repellents with higher molecular weights, making them less volatile and longer-lasting. Klimavicz has synthesized more than 300 compounds, the most effective of which are ?-terpinyl isovalerate (a natural compound), citronellyl cyclobutanecarboxylate and citronellyl 3,3-difluorocyclobutanecarboxylate.
To determine the compounds’ effectiveness as repellents against mosquitoes, Corona tests them in a tubular chamber developed in the Coats laboratory. The chamber has filter papers at either end. One filter paper has nothing on it; the other has the synthesized repellent applied. Then mosquitoes — raised in the Iowa State University medical entomology lab — are introduced into the chamber. Corona uses time-lapse photography and in-person monitoring over 2.5 hours to document whether the mosquitoes migrate away from the candidate repellents. The researchers are currently exploring computer tracking of mosquitoes using video footage to gain a better understanding of mosquito repellency and behavior when exposed to these compounds.
With this method, the researchers tested the repellents with Culex pipiens, the northern house mosquito, which is most closely linked to West Nile transmission in the Midwestern U.S.; Aedes aegypti, the yellow fever mosquito which is also known to transmit the Zika and dengue viruses; and Anopheles gambiae, which transmits malaria.
“We think the mechanism of our terpene-based repellents, which try to mimic what nature does, is different from that of the pyrethroids,” which many mosquito species have become resistant to, Coats says. “We believe these ‘next-gen’ spatial repellents are new tools that could provide additional protection against mosquitoes in treated yards, parks, campgrounds, horse stables and livestock facilities. Our next step is to understand more precisely how the repellents biologically affect the mosquitoes.”
This research will be presented at a meeting of the American Chemical Society
The Latest on: Mosquito repellents
via Google News
The Latest on: Mosquito repellents
- DEET-Free Insect Repellent Market to Perceive Incremental Opportunity by 2019 – 2029on January 25, 2021 at 1:49 am
DEET Free Insect Repellent Market Overview According to WHO every year approximately 200 million new malaria cases are identified globally and a significant number of deaths have occurred Hence insect ...
- Tajul for steps to eliminate Culex, Anopheles, Aedes mosquitoeson January 24, 2021 at 3:49 am
It is necessary to take pragmatic actions to eliminate Culex, Anopheles and Aedes mosquitoes and their larvae from the country, including the capital, to give relief to the people of the country.
- Mosquito Repellent Market 2021 | Demand, Trends and Analysis Research Report 2025on January 22, 2021 at 2:38 pm
Jan (AmericaNewsHour) -- Global Mosquito Repellent Market is estimated to reach $5,831 million by 2025; growing at a CAGR of 7.3% from 2017 to ...
- Water bodies, moat increase mosquito menace at Golconda Forton January 21, 2021 at 10:22 am
The mosquito menace in these areas is a round-the-year feature with several water bodies in the areas in addition to moat around the fort ...
- Cats like catnip for the euphoria, and because it repels mosquitoeson January 21, 2021 at 8:15 am
You may think that cats crave the plants catnip and silver vine because it makes them feel euphoric, and that's true -- but it also keeps mosquitoes away from them.
- Why Do Cats Love Catnip? It Gets Them 'High' And Protects From Mosquitoeson January 21, 2021 at 2:40 am
Why is it that cats go crazy for catnip and silver vine? It turns out, these herbs don't just get the felines "high," but they also protect them from pesky mosquitoes. It's no secret that felines act ...
- Study: Cats rub bodies against silver vine to repel mosquitoeson January 21, 2021 at 2:01 am
Although cats make it a habit of rubbing their bodies against silver vine, it's long been anyone's guess as to what causes this bizarre behavior. Now, researchers have found that felines rub against ...
- Global Body Worn Insect Repellent Industry (2020 to 2027) - Market Trajectory & Analytics - ResearchAndMarkets.comon January 20, 2021 at 8:37 am
ResearchAndMarkets.com The “Body Worn Insect Repellent - Global Market Trajectory & Analytics” report has been added to ResearchAndMarkets.com’s offering. The publisher brings years of research ...
- Global Body Worn Insect Repellent Market 2020 Revenue Share, SWOT Analysis, Product Types, Analysis and Forecast Presumption till 2025on January 19, 2021 at 6:27 pm
The latest informative study entitled Global Body Worn Insect Repellent Market 2020 by Manufacturers, Type and Application, Forecast to 2025 released for the database of MarketsandResearch.biz helps a ...
- Mosquito Repellents Market Future Growth Challenges, Size, Share, Demand, Trends, Revenue and Forecast to 2023on January 13, 2021 at 2:17 am
Mosquito Repellents Market Future Growth Challenges, Size, Share, Demand, Trends, Revenue and Forecast to 2023 
via Bing News