Frequently Asked Questions

A way to become less attractive to mosquitoes is to wear a commercially available, proven mosquito repellent. The District follows the Center for Disease Control recommendations on repellent.

CDC evaluation of information contained in peer-reviewed scientific literature and data available from EPA has identified several EPA registered products that provide repellent activity sufficient to help people avoid the bites of mosquitoes. Products containing these active ingredients typically provide reasonably long-lasting protection:

DEET (Chemical Name: N,N-diethyl-m-toluamide or N,N-diethly-3-methyl-benzamide)

Picaridin (KBR 3023, Chemical Name: 2-(2-hydroxyethyl)-1-piperidinecarboxylic acid 1-methylpropyl ester )

Oil of Lemon Eucalyptus* or PMD (Chemical Name: para-Menthane-3,8-diol) the synthesized version of oil of lemon eucalyptus

IR3535 (Chemical Name: 3-[N-Butyl-N-acetyl]-aminopropionic acid, ethyl ester)

EPA characterizes the active ingredients DEET and Picaridin as “conventional repellents� and Oil of Lemon Eucalyptus, PMD, and IR3535 as “biopesticide repellents�, which are derived from natural materials. For more information on repellent active ingredients see (http://www.epa.gov/pesticides/health/mosquitoes/ai_insectrp.htm). For more information on how to use repellents visit http://www.cdc.gov/westnile/index.html

No, mosquitoes live in many different habitats, and it is impossible to find and treat all of the places that they breed. Furthermore, mosquito control is not intended to eliminate mosquitoes. The goal of a mosquito control program is to reduce adult mosquito populations to a level that minimizes the possibility of people and animals getting sick from diseases associated with mosquitoes, and reduce biting to a level that most people find tolerable.

Limiting mosquito populations through active mosquito control is an essential public health function in Clackamas County.

Only adult female mosquitoes bite. Female mosquitoes need the protein in the blood to produce eggs. Not all species of mosquitoes bite humans – some species prefer birds, large mammals, or even snakes. During the aquatic stages of its life a mosquito feeds on algae and other small organic matter.

It is also important to remember that mosquitoes are not the only small flying insect that bites! Other small and biting insects are commonly mistaken for mosquitoes, including midges, no-see-ums, and black flies.

Mosquitoes typically fly a few hundred yards up to two miles from the place they emerge, depending on species and environmental factors. Some common mosquitoes in Oregon are known to fly 10 miles or more.

Some species of mosquitoes actively seek a blood meal during the daytime; others will bite during the daytime if you disturb them. It is important to remember that the mosquitoes that transmit disease in Oregon are much more active and aggressive around dawn and dusk, especially the two hours immediately following sunset.

Mosquitoes go to these cooler, humid, shady areas in your yard during the daytime to rest and escape hot dry air that will quickly kill them. Thinning shrubs and cutting down tall grass and weeds will reduce the harborage areas and number of mosquitoes in your yard.

The most important reason to control mosquitoes is to reduce the likelihood of diseases such as West Nile virus being transmitted to people through mosquito bites. Throughout history, no insect has been a more significant contributor to human discomfort, disease, and death than the mosquito.

Even mosquitoes that do not transmit disease can be bothersome in their biting behavior. In severe instances, nuisance mosquitoes can be economically detrimental to businesses, and reduce the quality of life for residents.

Mosquito control is the process of actively reducing the number of mosquitoes. Comprehensive mosquito control can use one or more approaches that target different environments and life stages of the mosquito.

Call in a citizen concern to Clackamas County Vector Control at : (503) 655-8394. We can inspect the pool for mosquito larvae.

There are four basic approaches to controlling mosquitoes: prevention, source reduction, larviciding and adulticiding. Preventing mosquitoes from breeding is the most desirable solution. Unfortunately, many human modifications of the environment such as ditches, retention ponds, and water management structures create mosquito breeding sites. Prevention requires working with planners to plan, construct, and maintain infrastructure without producing mosquito breeding habitats.

Source reduction is the elimination of water in which mosquitoes lay their eggs and in which the larvae develop or by containing water to eliminate areas for mosquitoes to lay their eggs. Source reduction is the second most effective method for controlling mosquitoes. Methods of source reduction involve eliminating containers that hold water and filling wet areas with soil. Larviciding is the use of materials to control immature stages of mosquitoes or prevent development of larvae from becoming adult mosquitoes. Larvicides are applied to waters that contain larvae and or pupae. Larvicides are effective in low concentrations and generally do not impact other organisms in the water or habitat. Every acre that is larvicided to prevent adult mosquitoes from emerging reduces the number of acres that must be treated with spray trucks. Clackamas County Vector Control has built a program focusing on larviciding to control mosquitoes.

Adulticiding is the last effort to control mosquitoes. Applied as directed, adulticide treatments have minimal effects on other insects. Clackamas County Vector Control is diligent in ensuring the proper size droplets and application rates are used. Adulticiding is done at night when adult mosquitoes are most active, which is also when most non-target insects like bees, dragonflies and butterflies are not as active.

Mosquitoes are relatively fragile insects with an adult life span that typically lasts 3-6 weeks. The vast majority meet a violent end by serving as food for birds, dragonflies, and spiders; or are killed by the effects of wind, rain, or drought. Some mosquito species may persist for as long as 5 months if environmental conditions are favorable. Content source: http://edis.ifas.ufl.edu/document_in652

Learn as much as you can about mosquitoes, then keep the areas around your home free of standing water, debris and overgrown vegetation. If you need information or assistance, contact us and we will be happy to help you. Refer to the following links on our web page: Hit Mosquitoes Where They Live.

The American Mosquito Control Association (AMCA) had a lot of great and useful information on their website.

Yes. Mosquito attraction to humans is a very complex matter. Primarily mosquitoes are attracted to the carbon dioxide (CO2) emitted from the breath and pores of humans. Mosquitoes are attracted to lactic acid, a by-product of human metabolism found in sweat. Mosquitoes are also attracted to fragrances, body heat, moisture, dark colors, and movement. During mosquito season it is recommended that people who wish to be less attractive to mosquitoes wear unscented products and light colored clothing. Odors produced by skin microflora also play a part in inducing the mosquito to land. Over 350 compounds have been isolated from odors produced by human skin. Either singly or in combination, many of these compounds may be attractants – and many may be repellents. Visual stimuli, such as movement, also factor into host-seeking behavior by mosquitoes. Mosquito attraction is complicated and will require many years of testing before it can be completely sorted out.

What can be safely stated, though, is that ingestion of garlic, vitamin B12 and other systemics has been proven in controlled laboratory studies to have no impact on mosquito biting. Conversely, eating bananas did not attract mosquitoes as the myth suggests, but wearing perfumes does. People drinking beer have been shown to be more attractive to mosquitoes. Limburger cheese has also been found to be attractive. Scientists have theorized that this may explain the attraction some mosquitoes find for human feet. Content Source: the American Mosquito Control Association at http://www.mosquito.org/faq#attracts.

A list of the pesticides used by the District can be found in our Annual Plan, appendix 4 Larvacides and Adulticides page. The pesticides we use are designed to be target specific and cause the least environmental disruption possible when used at the label rates dictated by State and Federal law.

You can contact the District at (503) 655-8394.

Call Clackamas County Vector Control at (503) 655-8394. Clackamas County Vector Control is responsible for the testing of dead birds for West Nile virus. Please note that birds must have been dead for 24 hours or less to be viable for testing. Birds that have obvious signs of trauma are not testable.

A vector is carrier of disease or infection, a disease or infection-carrying organism. The Clackamas County Vector Control District only deals with the following vectors: mosquitoes and flies.

You can call our office between the hours of 7:00 and 5:00 (Monday through Thursday) and request a fish delivery. Our phone number is: (503) 655-8394.

Usually we respond to your call within 24 to 48 hours (except for weekends).

You can fill out the Service Request Form or call us at the office and we’ll get a technician out to help you. Our phone number is: (503) 655-8394.

We are open Monday through Thursday, 7:00 a.m. to 5:00 p.m.

Clackamas County Vector Control

Clackamas County Vector Control