County tests mosquitoes at Timber Park
- Kim Jacobsen
- Estacada News - Features
Vector control program controls fly, mosquito populations
Timber Park is a great place for playing disc golf, fishing and picnicking, but while you are biting into that egg salad sandwich, you've got to be a little wary of what might be taking a bite out of you.
It is officially mosquito season, the time when those pesky critters lunch on your blood and then leave their calling card: a red welt that itches and irritates the skin for days. But that is not the only concern. Mosquitoes can carry serious diseases, including West Nile Virus, which can be severe and life-altering, and even cause death in people, horses, birds and other animals.
That is where Clackamas County Vector Control comes in. It is a special district in Clackamas County responsible for control of flies and mosquitoes within the county. This includes monitoring for West Nile and controlling it, following detection.
'We have nine zones in the county and we try to trap in each zone each week,' said Vector Control Staff Biologist George Cashdollar. Timber Park was selected as a sample site for Estacada and its surrounding area because of its proximity to the Clackamas River and its abundant summer food supply - meaning park visitors.
Cashdollar searched the park for the perfect spots to hang his three traps, which contained dry ice, a small intake fan and a short cylinder enclosed in netting. The dry ice produces carbon dioxide - the gas we breathe out that attracts mosquitoes. The intake fan pulls the mosquitoes into the traps, which are set in the afternoon and checked early the next morning.
'The ideal place for mosquitoes to breed is nice quiet, stagnant, sunlit water,' said Cashdollar as he hung a trap between a walking path and the river. All mosquitoes must have water in order to complete their cycle. They lay 100 to 400 eggs in a raft that floats on the top of stagnate water and, during warm weather, it takes only seven days to go from egg to adult mosquito.
He hung two more traps along another walking path that was buzzing with flying insects of all types.
The next morning Cashdollar returned to check the traps around the park. The three traps collectively netted eight mosquitoes, which he took back to his lab in the Clackamas County Vector Control office in Oregon City. Using a microscope, he was able to identify four of one species of vector mosquitoes. Vector mosquitoes are mosquitoes that have been proven to have the ability to transmit West Nile Virus effectively. He also found four non-vector, or nuisance, species. If more than 20 of one species of vector mosquitoes are found, they will also be tested for West Nile Virus.
'A Clackamas County Vector control field technician is conducting routine inspections and applying control products in the area if necessary,' said Rich Imholt, Clackamas County Vector Control Field Manager. The control products consist of a larvicide treatment made up of a granule substance placed in the water that does not allow mosquito larvae to develop to the adult stage. 'This way they are still available for forage by predators,' Imholt said.
Field technicians from Clackamas County will do routine inspections around Timber Park and will continue to treat if mosquito larvae are present, Imholt said.
To prevent mosquitoes from breeding, remove sources of standing water: Change water in bird baths, wading pools and animal troughs twice a week, clean clogged gutters, cover trash containers so they don't accumulate water, and check for containers or trash in places that may be hard to see.
Be sure windows and door screens are free of holes, wear long sleeve shirts and pants in outdoor areas with mosquitoes, and use mosquito repellent on skin and clothes. Mosquitoes are bad fliers, so two oscillating fans on the patio are an effective way to keep them away.
For more information, and to report a mosquito problem area:
An extensive collection of brochures, information sheets and articles on pests found in Clackamas County is available for public use at Clackamas County Vector Control District, 1102 Abernethy Road, Oregon City, 503-655-8394, vectorclackamas.com