The News

'Invasive mosquitoes are here!'

Columbia Drainage Vector control has recently discovered an invasive mosquito species in our district.

This species is called Aedes japonicus and is a container breeding mosquito (Tires, buckets, & other misc. artificial containers that hold water). We are asking everyone in the Columbia District to check your property for any type of container source that is capable of holding water and to please either empty them or treat them properly for mosquitoes.   Such containers would include not only large ponds, but also includes smaller water retainers like soda cans.

This mosquito is a very aggressive day-biting mosquito and is capable of transmitting diseases such as: West Nile virus, Dengue fever, Japanese encephalitis, Eastern equine encephalitis, Chikungunya, Rift Valley fever, and La Crosse virus.

Tires are particularly inviting to this species (and other Aedes mosquitoes) as it holds water at almost any angle and the dark color of the tire absorbs and retains heat very well in the colder beginnings of spring and through summer.

We are offering to collect up to ten tires per household as a way of source reduction of breeding sites. To do this, you will need:

(1.) Government photo I.D.

(2.) Show proof of residence within our district (PUD stub, etc.).

You may call us for tire pickup or deliver said tires to our shop location in St. Helens.


Links on Aedes japonicus mosquitoes:

1. European Center for Disease Control - Vectors: Ae. japonicus



*** Fun Facts about Aedes japonicus:

* It's origin is the main island (Honshu) of Japan. Today, this species is found in Belgium, France, China, South Korea, Panama, Russia, Taiwan, and the contiguous lower 48 United States.

* Discovered in 1901 by English entomologist - Fredrick Theobald.


Columbia Drainage Vector Control

We are located in St. Helens Oregon on the banks of the Columbia River and Multnomah channel.  Columbia Drainage Vector Control District is dedicated to protecting the public from vector borne disease by providing quality mosquito control using Integrated Pest Management practices.  (See Sidebar for IPM)

Above is a photo of St Helens, the Columbia County seat.  This photo is of the northernmost tip of Sauvie Island where the mouth of the Multnomah Channel meets the Columbia River.  In the spring the river rises to a flood level, inundating much of Sauvie Island and the mainland along the banks of the Columbia River and Multnomah Channel.  As this happens the water stimulates mosquito eggs laid along these banks to hatch.  These mosquitos hatch out in the millions per acre and can migrate up to 20 miles.

Above is a photo of Multnomah Channel looking south towards Scappoose from the Boise Cascade paper mill during the spring runoff.