Mosquito season has arrived early this year for many Oregon and Washington counties, especially along the Columbia River.
While we often think of mosquitos as hatching out of still water, the so-called “floodwater mosquito” lays its eggs in damp soil along rivers. So as mountain snow melts, those areas get covered and the eggs hatch.
Clark County Mosquito Control District manager Mario Boisvert said early water releases at the Bonneville Dam this year mean mosquito season started almost a month early.
“And it’s everywhere along what we call the crescent, from Washougal to Ridgefield,” he said. “We are currently seeing a lot of mosquito activity everywhere in the county but about one month earlier than last year.”
Over the last two weeks, Boisvert has received 550 calls to spray for mosquitos. Traps in Multnomah County are also catching large numbers of the insect. The season looks set to beat last year’s record.
The other reason the mosquitos are early this year is a spring warm spell.
“If you remember about three weeks ago, mid-May, we broke some records in temperatures,” Boisvert said. “We had 85 to 92 degrees, which is quite unusual. But mosquitos they really liked it.”
Oregon has 20 vector control districts that work to reduce insect-borne pathogens like the West Nile virus.
If the weather remains dry and the snow melt keeps a normal pace, then mosquito numbers could decline. But if there are major rains and heat, then numbers are likely to climb.
The best way to protect from bug bites is to use insect repellent or wear long sleeves and trousers. Homeowners can also help by getting rid of standing water around their properties.
Some local vector control agencies also offer free mosquito-eating fish for local waterways.
Here are more tips for avoiding mosquito bites, from Clark County Public Health:
- Install or repair screens on windows and doors.
- When possible, stay indoors during dawn and dusk when mosquitoes are most active.
- Place mosquito netting over infant carriers when outdoors.
- Use EPA-registered insect repellents, including those with DEET, picaridin, IR3535 or oil of lemon eucalyptus. Use especially at dawn and dusk. Read the label and carefully follow the instructions for applying repellents, especially when applying to children.
And tips to help prevent mosquitoes from breeding:
- Drain standing water from old tires, flowerpots, buckets, plastic tarps and wheelbarrows.
- Change water in bird baths, ponds, wading pools, pet bowls and animal troughs at least twice a week.
- Repair leaking faucets and sprinklers; clean clogged gutters.
- Properly maintain swimming pools.
- Check for containers or trash in hard-to-see places, such as under bushes.
