Joel Buettner, General Manager for Placer Mosquito & Vector Control district, with Mario Boicvert also present, gave a brief history of the organization and presentation on the current status of mosquito and vector related issues in the area. The organization first started to combat malaria outbreaks among settlers through the gold rush days. By 2001, their organization was well established to protect against diseases carried by ‘vectors’ -- mosquitos, ticks, and yellow jackets mainly. Placer County was the first to set up a system to battle these vectors.
Mr. Buettner indicated there are many different kinds of mosquitos; he indicated we are especially susceptible in this area because of our proximity to the rice fields. The first influx usually comes in the fall from the Anopheles mosquito variety -- while they can be quite annoying, they do not carry diseases. However, other forms of mosquitos do carry diseases, including West Nile Virus.
Vector Control targets to control them in the winter to keep them from growing into adults in summer. They analyze where their resources can be most effective:
• Source Reduction—eradicating them in early breeding stages in standing water
• Biologic Control—supplying mosquito fish to eat the mosquitos, reducing the population
• Larvicides—kill larvae in water with cropdusters that drop bacteria that eat larvae
• Adulticides—deal with adults (West Nile carriers), wide area treatment spraying through aircraft.
All treatments use materials approved for usage around people. However, results are showing vectors are becoming more resistant. It is important to report dead birds -- the mosquitos bite birds, then bite people; so report dead birds when you see them so Vector Control can pick them up (probably the same dead), test the birds, and treat the area accordingly. Different types of mosquitos have different travel ranges and life spans. A small population of mosquitos usually stay within a quarter-mile radius and have a general life cycle of 2-4 days. Anopheles can travel 15 miles and life one year. West Nile carriers have been researched to travel 1-5 miles.
Area testing is routinely done -- 40-50 weekly trappings to get counts, identify types, grind and test for West Nile. The results of ‘dipping’ tests may show larva counts requiring immediate action in an area. Unfortunately, it will probably be 4-6 weeks for people to become sick and go to a doctor.
Mr. Buettner said the 2015 West Nile found in humans report was better than 2014, the highest report was in 2012, but it has diminished a bit. Department of Public health showed no human cases last year in Placer County. The last few years, the range of West Nile has been spreading along the coast, including two types of Aedes (Asian) mosquitos. We don’t have carriers of the ZICA Virus here yet, only cases from surrounding counties or identified from other areas. Eggs can dry out, lay dormant for years, and then become active when hydrated in the future. The more aggressive mosquitos that bite during the day (“day-biters’) are bad mosquitos that carry diseases, so if you notice them report them immediately to Vector Control.
How can neighbors help: Some products can be obtained ‘over the counter’, like BTI, they work good, but they may lead to the mosquitos becoming more resistant. Come July and August, if you see standing water, report it. If it’s a large area, or like pools left standing, they can supply mosquito fish to eat them. Keep pools and fountains running appropriately every day to disrupt the surface of the water and keep them from laying eggs. Chlorine helps, but some are becoming chlorine resistant. Practice good water conservation -- keep yards drained.
More information is available on the Placer Mosquito & Vector Control website.
Download the presentation here:
WestPark and Fiddyment NA 2016.pdf