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Date: June 20, 2003
Posted by: Blaine P. Friedlander Jr. (bpf2@cornell.edu)

CORNELL SCIENTISTS DEVELOPING ONLINE WNV WARNING SYSTEM
by collecting climate and mosquito data

ITHACA, N.Y. — In combating West Nile virus, information could be 
the ultimate repellant. In an effort to develop an early-warning 
system for potential West Nile virus outbreaks, Cornell University's 
Northeast Regional Climate Center (NRCC) and the Department of 
Entomology will spend this summer collecting climate data in areas 
where disease-carrying mosquitoes are found.

The U.S. government-funded research, it is hoped, will result in the 
first Web-based, degree-day calculator that warns public health 
officials when, where and under which conditions infectious 
mosquitoes can either thrive or die. The information is expected to 
be on line by next summer.

"Scientists, whether they are climatologists or medical 
entomologists, have never fully examined the relationship between 
climate and the proliferation of the mosquitoes that carry West Nile 
virus," says Arthur T. DeGaetano, Cornell associate professor of 
climatology and director of the NRCC, is one of the principal 
investigators on the project. "Cornell's College of Agriculture and 
Life Sciences is unique in that collaborations like this are very 
possible. Interaction between climatologists and medical 
entomologists can be at a level where information — once it is 
gathered and processed — can be readily employed in vector 
management schemes," he says.

The research, funded by the National Oceanic and Atmospheric 
Administration, will occur in four stages. First, climatologists and 
entomologists will gather climate data and synchronize this with 
mosquito habitat observations. These data then will be related to 
mosquito-count information through statistical analysis for mapping 
and graphing. From this information, indices will be developed for 
moisture surpluses, degree day-based mosquito development and killing 
freezes. Finally, all this data will be put on the Web for public 
health officials' use.

Mosquitoes develop in microhabitats, according to Laura Harrington, 
Cornell assistant professor of entomology and a co-principal 
investigator on the project. The correlation of climate data with 
microhabitat information will provide scientific clues to how 
mosquito populations develop and age. Older mosquitoes are the 
carriers of West Nile virus, becoming contaminated when they feed on 
infected "reservoir" animals such as birds, and undergo an incubation 
period of the virus that can last 7-14 days. During subsequent blood 
meals after this incubation period, the mosquitoes inject the virus 
into humans and animals, where it can multiply and sometimes cause 
illness. It is outdoor temperatures that determine both the rate at 
which the virus replicates and the rate at which mosquitoes age.

While mosquitoes can live as long as three or four months in a 
laboratory, their life span in the wild is much shorter. Thanks to 
predators and pathogens, the longest a mosquito can live is probably 
three to four weeks, says Harrington. During the height of summer 
heat, a mosquito can age and become a full adult within seven to nine 
days.

The study also will gather information on early establishment and 
climate-influenced development of mosquitoes carrying West Nile virus 
in specialized habitats such as discarded tires and other types of 
containers that tend to be located close to human dwellings.

Catherine Westbrook, a Cornell graduate student in entomology, and 
Renee Anderson, a medical entomology extension associate, will 
monitor mosquito microhabitats in several Northeast locations this 
summer.

The web version of this release may be found at 
http://www.news.cornell.edu/releases/June03/WestNileClimate.bpf.html

FOR RELEASE:  June  19, 2003

Contact:  Blaine P. Friedlander Jr.
Office:  607-255-3290
E-mail:  bpf2@cornell.edu
Cornell University News Service

cunews@cornell.edu
http://www.news.cornell.edu

Thanks to Brian Sauders, Cornell Department of Food Science, for 
submitting this news release.

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