Flood Waters – Increased Mosquito Numbers

Due to unusually warm temperatures this May, above average snow pack and high water levels around the Columbia and the creeks that flow directly into it we have the perfect situation for mosquitos. Our area is home to a number of different mosquito species and each can have different characteristics.  Some species of the genus Aedes, which are predominantly the challenge in our area, have a creative way of perpetuating the species.  The females will put their eggs into moist soil in anticipation of a rise in the water level.  If the water recedes instead of rises, then the eggs dry out but are still alive.  They can stay in the soil for years.  Then, when water covers the eggs (like when the Columbia River is really high, we use the term flood waters) the eggs re-hydrate and hatch.

We are experiencing an increase in mosquito development and hatching along river areas due to this multi-pronged scenario, of warm weather, flooding, and the “right” type of mosquito.  Increased numbers will likely continue until water levels establish consistent, and hopefully normal, channels.

Additionally, warmer to hot temperaturs shorten the time it takes for mosquitoes to go from eggs, to larvae, to pupae, to adults.  So, this will also lead towards increased mosquito production.

We are actively checking and treating water sites for mosquito larvae, but areas along the Columbia River that have flowing water cannot be effectively treated, so there will be an unavoidable increase in mosquitoes present in certain areas.  We encourage people to consider using an EPA registered mosquito repellent and/or, if possible, avoiding areas of increased mosquito activity during dusk and dawn, which are typically times of increased mosquito activity. 

Keeping water around your house to a minimum does help with reducing the ability for mosquitoes to lay eggs.

We have updated the adulticiding tab as we plan to be out this week, weather permitting; wind is a factor.