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Enjoying mosquito visits?

Columbia Drainage Vector Control can be of assistance
by: John Brewington MOSQUITO EXAM–Seasonal employee Seth Honl looks at a scoop of water to see if he can spot any mosquito larvae. Vector control can help rid your backyard of mosquitoes.

Has your backyard been plagued by swarms of mosquitoes this summer? Been in a park infiltrated with the nasty buzzing insects? There is something you can do about it and you've probably already paid your share for the service.

The Columbia Drainage Vector Control district has had its hands full this season trying to knock out mosquito infestations, but they're making progress. And like the DJ at a dance, they gladly take requests.

Mel Franklin, director of vector control, said they spend their time trying to eradicate two types of mosquitoes-flood and the common backyard type.

With the wet spring and high water levels this has been a particularly difficult year for vector control. Franklin said the flood mosquitoes are out in force. They can stay dormant for five years (and in some cases up to 20 years) before a combination of water and temperature cause them to hatch.

'Floodwater is a double threat,' Franklin noted. 'When mosquitoes hatch, the female can fly up to 20 miles in search of a blood meal. They lay their eggs and they can stay viable for up to five years. In some cases they found they are (viable) up to 20 years.'

The vector control district runs along the Columbia River from county line to county line, echoing the Port of St. Helens' boundaries-7-10 miles inland from the river. The district was established under the special districts law enacted in 1968. They had operated for about five years before that under the county health department. The district receives tax money-just under 13 cents per thousand dollars, or about $26 a year for a $200,000 home.

There are only two full-time employees of the district, including Franklin. They hire three season employees. He said the winter is spent plotting their attack for the coming season.

'We have literally hundreds of sites we have inspected and treated,' he said.

Floodwater mosquitoes are treated by air with fogging at nighttime from a contracted helicopter. Backyard mosquitoes are treated with fogging sometimes, or spraying, or simply getting potential hatching sites cleaned up.

'This time of year we are trying to get all the storm drains cleaned. Mosquitoes are in the water that drain in those, as well as tires, and water features,' he added.

One effective treatment is a little 'minnow' called gambusia afinis, also known as the mosquitofish. The fish, no bigger than a little finger, goes after mosquitoes in the larval and pupal stages with a passion. They can survive in low oxygen and high salinity water environments. The fish breeds like guppies and can live 2-3 years. The fish are available for free from the Vector Control office on Old Portland Road.

Franklin said new housing subdivisions could create their own mosquito environment in water retention areas. Beaver ponds also provide breeding grounds.

Franklin knows well most areas where mosquito treatments are frequent. Asked about a certain location, he describes it better than the questioner, names the owner, and says he has a key to its gate.

Vector control aims to please as well. He says requests to treat a certain area because of an upcoming wedding, large birthday or other outdoor event are handled as quickly as possible-usually within a couple of weeks.

The district has a mosquito surveillance and identification program that can help find affected areas. They also take samples of mosquitoes to try and detect the West Nile virus or the Western Equine virus. They also examine dead birds, such as jays, crows, or sometimes raptors like hawks to see if a virus transmitted by mosquitoes has affected them.

The vector control district provides a valuable service to the area, but may not be as well known as some other districts. They suggest giving them a call if you have problems and they will help if they can.

Who ya' gonna call?

One way to get some help from mosquitoes is to go on the vector control website and and click on the requests tab. The site is located at www.cdvcd.org

They can also be reached by calling: Columbia Drainage Vector Control District at 503-397-2898.