Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Forget rainy springs

14.10.2003


Sculpture by Wesley Anderegg, Lompoc, Calif.
Courtesy photo


Previous year’s drought might predict following year’s mosquito population

So you think you know mosquitoes?

Consider the venerable law that rainy weather is the cause of increased mosquito populations.



An ecologist at Washington University in St. Louis says if you believe that, youre all wet.

Jon Chase, Ph.D., assistant professor of biology in Arts & Sciences at Washington University, and his wife Tiffany Knight, Ph.D., a postdoctoral researcher at the University of Florida, have found that the previous years’ drought is the cause of high mosquito populations coming out of wetlands in the following year. This is because some wetlands, which are the home to mosquito larvae, dry during drought years, drastically reducing mosquito predators - from fish to water beetles - and competitor species such as snails, tadpoles, and zooplankton.

This conclusion stands the ecological world on its head and, with more extensive scrutiny, eventually could have implications in prediction and control of diseases like West Nile virus, St. Louis encephalitis and malaria that are all carried by mosquitoes. The study will appear in the November issue of Ecology Letters.

Chase and Knight are now analyzing data from locales across North America to see if their results found in local wetlands translate to larger spatial scales.

"We’re dealing with the ecology of mosquito larvae in wetland food webs and trying to see if this translates to the landscape level," said Chase. "This is important because mosquitoes live in all sorts of habitats besides the ponds, marshes, and swamps that we studied. Consider treeholes, tires and puddles. With the data we have we’re trying to run correlations between precipitation and mosquito density over 20-year and 30-year spans to see how well our hypothesis predicts mosquito abundance. We’ve found that the current year’s precipitation explains almost nothing but the past year’s precipitation explains a lot. "

The team also is looking into disease implications.

"This (disease) is much harder to prove because there is so much epidemiology to take into consideration, for instance the role of intermediate hosts and other complexities," Chase said . "Very few people are looking at these mosquito-borne diseases in a modern ecological context. Most of the work comes from the epidemiological, genomic and/or molecular biology perspectives."

Chase, a community ecologist, and Knight, a population ecologist, came to their conclusion by accident. A pond they had been studying in Pennsylvania dried up during a drought and the next year, after the pond was replenished, mosquito larvae came back like gangbusters. They then surveyed approximately 30 ponds, some permanent but others semi-permanent and temporary. They found few mosquito larvae in permanent ponds but lots of mosquito predators; in ponds that dried up annually mosquito larvae were scarce because of lots of competitor species, zooplankton, snails and tadpoles. Those ponds that were usually full but dried out after a 1999 drought, however, had lots of mosquito larvae and very few predators and competitors because, Chase and Knight reason, those species aren’t adapted to dry spells in these ponds.

The team was able to recreate this natural study by filling tanks with soil and water and stocking them with mosquito larvae and other species found in natural ponds. They gave these artificial ponds three years to allow the ecosystem to form and stabilize, and then slowly drained some of the tanks to simulate a drought. The next year, the mosquito larvae numbers were very large compared with tanks that were drained each year or remained full.

Analyzing data provided by the city of Winnipeg, Canada, Chase and Knight found that drought the previous year is a much better predictor of high mosquito populations than the current year’s rainfall.

Tony Fitzpatrick | WUSTL
Further information:
http://news-info.wustl.edu/tips/page/normal/426.html
http://www.wustl.edu/

More articles from Ecology, The Environment and Conservation:

nachricht How to detect water contamination in situ?
22.09.2016 | Tomsk Polytechnic University (TPU)

nachricht Quantifying the chemical effects of air pollutants on oxidative stress and human health
12.09.2016 | Max-Planck-Institut für Chemie

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

Im Focus: Complex hardmetal tools out of the 3D printer

For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.

Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...

Im Focus: Launch of New Industry Working Group for Process Control in Laser Material Processing

At AKL’16, the International Laser Technology Congress held in May this year, interest in the topic of process control was greater than expected. Appropriately, the event was also used to launch the Industry Working Group for Process Control in Laser Material Processing. The group provides a forum for representatives from industry and research to initiate pre-competitive projects and discuss issues such as standards, potential cost savings and feasibility.

In the age of industry 4.0, laser technology is firmly established within manufacturing. A wide variety of laser techniques – from USP ablation and additive...

Im Focus: New laser joining technologies at ‘K 2016’ trade fair

Every three years, the plastics industry gathers at K, the international trade fair for plastics and rubber in Düsseldorf. The Fraunhofer Institute for Laser Technology ILT will also be attending again and presenting many innovative technologies, such as for joining plastics and metals using ultrashort pulse lasers. From October 19 to 26, you can find the Fraunhofer ILT at the joint Fraunhofer booth SC01 in Hall 7.

K is the world’s largest trade fair for the plastics and rubber industry. As in previous years, the organizers are expecting 3,000 exhibitors and more than...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Experts from industry and academia discuss the future mobile telecommunications standard 5G

23.09.2016 | Event News

ICPE in Graz for the seventh time

20.09.2016 | Event News

Using mathematical models to understand our brain

16.09.2016 | Event News

 
Latest News

Chains of nanogold – forged with atomic precision

23.09.2016 | Life Sciences

New leukemia treatment offers hope

23.09.2016 | Health and Medicine

Self-assembled nanostructures hit their target

23.09.2016 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>