Posts Tagged: mosquito
Mark your calendars for a sobering experience.
The University of California,Davis, will observe World Malaria Day with a daylong retreat showcasing UC Davis scientists’ current research in vector biology and genetics.
The event, free and open to the public, will take place from 9 a.m. to 4 p.m., Monday, April 25 in Room 1102 of the Gourley Clinical Teaching Center, School of Veterinary Medicine, on Garrod Drive.
Malaria is a killer. "Approximately half of the world's population is at risk of malaria, particularly those living in lower-income countries," according to the World Health Organization (WHO). "It infects more than 500 million people per year and kills more than 1 million. The burden of malaria is heaviest in sub-Saharan Africa but the disease also afflicts Asia, Latin America, the Middle East and even parts of Europe."
Postdoctoral researchers Becky Trout (email@example.com) and Michelle Sanford (firstname.lastname@example.org) are organizing the event, and issued this statement: “Malaria remains one of the most deadly vectorborne diseases in the world. Worldwide programs continue to rely on control programs based on the most recent research available. In honor of the Roll Back Malaria Program, promoting the education and research in the fight against malaria, student and researchers at UC Davis engaged in vector biology and genetics will come together to discuss their research efforts.”
During the breaks and during lunch, attendees will see a photo slide show of research experiences.
Malaria researchers associated with the UC Davis Department of Entomology include graduate student advisors Anthony “Anton” Cornel, associate professor, Department of Entomology; Shirley Luckhart, professor, Department of Medical Microbiology and Immunology, UC Davis School of Medicine; and Gregory Lanzaro, professor, Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine.
Through their research and public involvement, they're all doing their part to control a killer.
Whew, that stinks!
If you've ever smelled a mosquito gravid trap, you know it's not heaven-scent. This isn’t about the aroma of summer roses or the whiff of freshly baked cinnamon rolls or the fragrance of vanilla-laced skin cream.
No. This is something that stinks to high heaven. Probably low heaven, too.
It’s s-o-o bad (how b-a-d is it?) that you just want to distance yourself from the stench: you hold your nose, mutter “P.U.” and make like a Lightening Bolt (Olympic gold-medal sprinter Usain Bolt).
Said UC Davis chemical ecologist Walter Leal: “It smells like a latrine."
So he and his researchers set out to find a synthetic mixture that attracts mosquitoes but is odorless to humans. And they have. Their mixture, containing the compounds trimethylamine and nonanal in low doses, lures Culex mosquitoes just as effectively as the current gravid trap attractants. But look, ma, no smell!
They did it with what Leal calls "reverse chemical ecology."
The results are published in the current edition of the Public Library of Science Journal or PLOS One.
This research could play a key role in surveillance and control programs for Culex species, which transmit such diseases as
What are gravid traps? They're chemical- and water-infused traps, sometimes called oviposition traps or ovitraps. They're meant to attract blood-fed mosquitoes searching for places to lay their eggs. Scientists monitor these traps to determine the presence of West Nile-infected mosquitoes.
“The gravid traps are more important (than carbon-dioxide traps) for surveillance,” Leal said, “as they capture mosquitoes that have had a blood meal and thus, more opportunity to become infected.”
Leal said that another advantage of the gravid traps is that with the capture of one female mosquito, that eliminates not only her, but hundreds of her would-be offspring. “Each female mosquito has the potential to produce about 200 eggs, and she can have as many as five cycles. So when we capture a gravid mosquito, that can remove as many as 500 females.”
The compounds used in the research, Leal said, are “simple and inexpensive” and would be of great benefit “to not only us but third-world countries where Culex quinquefasciatus is a problem.”
The researchers did preliminary field testing in
Other scientists involved in the study included UC Davis researchers Wei Xu, Yuko Ishida,
(See more information on the UC Davis Department of Entomology Web site)./st1:personname>/st1:personname>/o:p>/st1:place>/st1:country-region>/st1:city>/st1:city>/st1:city>/o:p>/o:p>/st1:place>/o:smarttagtype>/o:smarttagtype>/o:smarttagtype>/o:smarttagtype>
Culex quinquefasciatus laying eggs
Water for mosquito gravid trap
We know it works, but how?
Just how does DEET work? Does it jam the senses of a mosquito? Does it mask the smell of the host?
You spray the chemical repellent on your arm and thankfully, those darn skeeters leave you alone. They need a blood meal to develop their eggs, so off they buzz to find another host, one that’s not so inhospitable.
But why do mosquitoes avoid DEET?
Well, they avoid it because it smells bad to them. Yes, they can smell it--that's why they avoid it.
The groundbreaking research, the work of UC Davis chemical ecologist Walter Leal and researcher
The research contradicts a Science article published in March by researchers at
The Leal-Syed research solidly establishes the real mode of action.
Noted entomologist James "Jim" Miller of
Said Miller: "For decades we were told that DEET warded off mosquito bites because it blocked insect response to lactic acid from the host -- the key stimulus for blood-feeding. Dr. Leal and co-workers escaped the key stimulus over-simplification to show that mosquito responses -- like our own -- result from a balancing of various positive and negative factors, all impinging on a tiny brain more capable than most people think of sophisticated decision-making.”
“This new work corrects long-standing erroneous dogma, and shows that recent work on DEET mode-of-action published in the flagship journal, Science, apparently was flat-out wrong,” Miller said. “One of the great attributes of science is that, over time, it is self-correcting."
Leal, past president of the International Society of Chemical Ecology and former chair of the UC Davis Department of Entomology, said previous findings of other scientists showed a “false positive” resulting from the experimental design.
Now that we know that skeeters can smell it, this will no doubt lead to better methods of insect control. Or, as
Those darn female mosquitoes, always in a “Let-us-prey” mood, have clearly met their match: the "why" behind "Let us spray."
(For more information and a video,access this page.)
I've always loved the wit and wisdom of insect-inspired poets.
God in His wisdom made the fly
And then forgot to tell us why.
We hope that, when the insects take over the world, they will remember with gratitude how we took them along on all our picnics.
- - Richard Vaughan
If you look at the world through a viewfinder--as I have a habit of doing--it’s a wonderful, exquisite place, especially if you capture critters in their natural habitat. They don’t complain when you make them look fat, skinny, nice or ferocious.
Blow flies, honey bees, carpenter bees, spotted cucumber bees, the ten-lined June beetle, and mosquitoes all appear in my viewfinder. Okay, I know. We’re not supposed to like some of these pests (such as the carpenter bees, spotted cucumber bees and the ten-lined June beetles), but hey, all of them are pretty enough to sing the national anthem at the Olympics.
Photography, or writing with light, is just that. Writing with light. Back before the digital technology age, we used to process film, make prints and then hang them out to dry. We "pho-togs" marinated ourselves in Dektol, DK-60 and Hypo.
Our "pheromone" wasn't always appreciated. But the images were.
But the images were.
Bees are black, with gilt surcingles,
Buccaneers of buzz.
- - Emily Dickinson
The mosquito is the state bird of
- - Andy Warhol
Ten-lined June beetle
Bee on pomegranate blossom
Spotted cucumber beetle