Mosquito-borne disease a rising threat

New research suggests that by 2050, half the world’s population could be at risk of mosquito-borne diseases like dengue fever or the Zika virus. A combination of environmental change, urbanization and human movements around the world are helping mosquitoes spread into new areas, according to the findings, reported Monday in the journal Nature Microbiology. You can read the full study here.



When Should I Call Vector Control?

When Should I Contact Vector Control?

Contact our office if:

  • You are bothered by mosquitoes, a trained employee will investigate and lend assistance.
  • You need help to prevent or control mosquito breeding in your backyard.
  • You have an ornamental pond, unused swimming pool or an animal drinking trough, mosquito fish will be furnished without charge.

Mosquito Life Cycle

Mosquito Life Cycle


The most common mosquitoes lay egg rafts that float on the water. Each raft contains from 100 to 400 eggs. Within a few days the eggs hatch into larvae.


The larva or “wiggler” comes to the surface to breathe through a tube called a siphon. It sheds its skin or molts four times during the next several days. It grows rapidly between each molt. On the fourth molt it changes into a pupa.


The pupa or “tumbler” cannot eat. It breathes through two tubes on its back. The adult mosquito grows inside the pupa and in two days or so, when it is fully developed, it splits the pupal skin and emerges to complete the life cycle or metamorphosis of the mosquito.


The newly emerged adult rests on the surface of the water until it is strong enough to fly away and feed.

Insect Trivia

Insect Trivia

Q. What is Oregon’s state insect?

A. The Swallowtail Butterfly

Q. What is the most dangerous insect?

A. The mosquito because it carries so many deadly diseases

Q. How long does it take for a mosquito to “hatch”?

A. Only seven days are required to complete their life cycle (egg to adult mosquito) during warm weather. The “tree hole” mosquito can breed and develop in the small amount of water that collects in holes or crevices of trees.

Mosquito Facts

Mosquito Facts

There are over 3300 species of mosquitoes worldwide. It is responsible for more human deaths than any other living creature (source: Metropolitan Mosquito Control District, St. Paul, MN).

There are 48 known species of mosquitoes in Oregon. Several of the species found in Oregon can carry disease under the right conditions.

All mosquitoes must have water in which to complete their life cycle.

Only female mosquitoes suck blood.

The males feed only on plant juices.

It takes as few as 7 days in warm weather for a mosquito to complete its life cycle (egg to adult).

The female mosquito may live as long as 3 weeks during the summer. She can also live many months over the winter in order to lay her eggs the following spring.

Personal Protection from Mosquitoes

Personal Protection from Mosquitoes

May and June are frequently the worst months in our area for mosquitoes. The Vector District controls mosquitoes in large breeding areas on public and private property, but cannot find and control backyard breeding sources where neighborhood mosquitoes develop. For a more enjoyable spring and early summer, we offer the following suggestions:

  • Avoid peak periods of mosquito activity. In May and June, plan your outside activities to avoid the peak times of one hour before to one hour after sundown.
  • Wear protective clothing or use mosquito repellent when you must be exposed to mosquitoes outside. Although somewhat less effective than repellents, oil of citronella is another type of mosquito repellent for outside use. It is the active ingredient in many of the candles, torches, or coils that may be burned to produce a smoke which repels mosquitoes. These are useful outdoors only under windless conditions

Where Did The Name Mosquito Come From?

Where Did the Name Mosquito Come From?

The Spanish called the mosquitoes, musketas.

The native Hispanic Americans called them zancudos.

The word mosquito is Spanish or Portuguese meaning little fly, while zancudos, also a Spanish word, means long-legged.

The use of the word mosquito is apparently of North American origin and dates back to about 1583.

In Europe, mosquitoes were called gnats by the English, Les moucherons or Les cousins by French writers, and Stechmucken or Schnacke by the Germans.

In Scandanavian countries, they called mosquitoes by a variety of names including myg and myyga while the Greeks called them konopus.

In 300 B.C., Aristotle referred to mosquitoes as empis in his Historia Animalium where he documented their life cycle and metamorphic abilities.

Modern writers used the name Culex and it is retained today as the name of a mosquito genus.

What is the correct plural form of the word mosquito? In Spanish it would be mosquitos, but in English mosquitoes (with the e) is correct (Source: The American Mosquito Control Association).

Mosquito Control Around Your Home

Mosquito Control Around Your Home

Learn How to Protect Your Home from Becoming a Mosquito Breeding Ground

Many of the mosquitoes found around your home have bred on or around your or your neighbor’s property. Mosquitoes require standing water for their production. Eliminating standing water early in the spring will reduce the production of those summer mosquitoes.

Here are a few ideas for searching out and eliminating potential breeding grounds for mosquitoes:

  • Keep bird baths and ornamental ponds clean. In warm weather, change water weekly. Call the Vector District to have Gambusia affinis placed in your pond.
  • Remove leaves from gutters so water will flow freely. Fill or drain puddles, ditches and swampy areas.
  • Eliminate standing water around animal watering troughs.
  • Check around faucets and air conditioner units and repair leaks and eliminate puddles that remain for several days.
  • Dispose of, or store in a dry place, any cans, bottles, tires, and any other containers that hold water.
  • Cover boats or store upside down or in a dry place.
  • Where feasible, fill all holes in the trees on your property.
  • When swimming season is over, empty and store wading pools in a dry place. Cover large pools and check frequently to insure against mosquito breeding. Pool chemicals like chlorine, at ordinary concentrations, will not kill mosquito larvae.

Elimination of standing water must be done no later than early April to reduce later mosquito problems. Continue to monitor potential breeding grounds throughout the summer.

Facts About Gambusia Affinis – “Mosquito Fish”


  • Gambusia affinis are indispensable to our mosquito control program.
  • Mosquito fish are furnished _without charge_ for stocking ornamental ponds, unused or out-of-order swimming pools, and animal troughs.
  • They require no feeding and care is limited to protecting them from garden sprays and chlorine or other chemicals used to clean ponds.
  • Mosquito fish do not lay eggs, but rather give birth to well developed and very active young. Therefore, they require no special environment, as other fish do, for depositing and hatching their eggs.
  • They breed throughout the summer and new broods are produced at intervals of about six weeks, with 50 to 100 young in a single brood. The young are about 1/4 inch in length when born and are ready to begin their work of eating larvae at once.
  • Gambusia affinis grow rapidly, reaching a maximum size of about three inches. The earliest broods of the season, born in April and May, become sexually mature and produce young when six to eight weeks old.
Ornamental Ponds

Stock the ponds with mosquito fish, you can even add goldfish for looks if you desire. Avoid spraying the pond with garden insect sprays and don’t chlorinate the pond, it kills the fish! If you need to clean the pond, put the fish into a small glass bowl and then clean. Remove leaves and thin out pond lilies from the pond, always keeping the water level up. Always remember to keep the inlet of the recirculating pump screened. If the pond is no longer desired, you can always break holes in the bottom of the pond and fill the pond with dirt or sand.

Concrete or Plastic Swimming Pools

Operate filter and skimmer everyday to remove egg rafts and larvae. Provide drainage for filter and pump sumps. Chlorine will not kill mosquito larvae. If the pool cover is used, keep it tightly sealed. Remove rainwater from the top of pool covers, so that the mosquitoes have no chance to lay eggs. Stock unused or “out-of-order” pools with mosquito fish, or make ornamental ponds out of them.


Prevent accumulation of bilge water. Store small boats upside down or cover to keep out the rain and water from sprinklers.

Animal Water Troughs

Stock large troughs with mosquito fish, dealing with smaller troughs requires cleaning every week.

Other Kinds of Containers

Remove and dispose of all unused containers that will collect rain or water from sprinklers. These containers include: cans, jars, barrels, old tires, buckets, tubs, etc. Home gardeners rooting plant cuttings in vases, buckets, etc; should change water every week.

Usable containers should be stored upside down.