Some have complained that the Mosquito District has not been spraying this year, saying that the District is “doing nothing” about the mosquitoes.
Irrigation in theNorth ForkValleyhas enabled the valley to flourish. However, irrigation can also cause mosquitoes to flourish. This year, the combination of irrigation, unseasonably hot weather, and an early drop in the flow of the river has resulted in high mosquito populations. This makes the Mosquito District look bad, and to some, the lack of the smell of poison in the air means the District must be “doing nothing.”
Of course, if you wish to see for yourself how the District is “doing nothing,” you may call the District field office at 527-6681 and volunteer to ride along with one of the District’s four full-time technicians, as they scour the 50 square miles of the District, monitoring and treating over 500 mosquito breeding sites.
To ride along, you will need to be at the “shed” on O Road, just south of Matthews Lane in Paonia, no later than 6 a.m. Bring your irrigation boots. Depending on the route, you may want to wear waders. Of course, long pants are preferable to shorts. We recommend that you wear a hat and use sun block and insect repellant. Bring plenty of drinking water. And possibly, carry a machete. It can be a long day.
At the end of the day, you can decide which is closer to “doing nothing” — hiking through ravines and underbrush and swampy fields of cattails, carrying a 40-to-50-lb backpack blower of larvicide, five days a week, every week of the hot summer months, killing juvenile mosquitoes before they hatch into flying adults; or, driving each area once a week, fogging the streets with poison.
If you are wondering why the “doing nothing” District is going to so much trouble to tramp through so many practically impassible areas of brush and undergrowth, ask some of the people who remember just a few years back, when the District was spraying weekly.
Several locals lost their honeybees. Birds and frogs and butterflies were scarce, too. Some residents fled the valley for the entire summer due to the way the spray affected their health. Others huddled behind closed doors and windows, with air conditioning shut off, in 90+ degree weather.
So, what is the benefit of weekly fogging? Well, the benefit is that residents see and hear and smell that the District is “doing something”. This comforts residents, so they conclude that they do not need to protect themselves. There is peace of mind.
Yet, during that time of weekly fogging, our valley had the highest per capita incidence of West Nile Virus in the entire state. Some trade-off — exposing ourselves and our children to toxins that kill all sorts of beneficial wildlife and results in high rates of human WNV in exchange for a false sense of security, a fraudulent peace of mind.
Depending on the wind speed and direction, fogging may kill no more than ten to thirty percent of the adult mosquitoes that are within a few dozen feet of the pickup, on the downwind side of the fogger. It has a kill rate of zero for the mosquito larvae that will become adults over the next few days, no matter where they are. The kill rate is near zero for mosquitoes on the side of your house away from the street.
To kill, the fog has to encounter a mosquito in flight. That is why the spray is called “fog”. The fogger emits Ultra-Low Volume particles in an attempt to suspend them in the air for as long as possible. This improves the chances that the fog will hit a flying adult mosquito. It also means chances of inhaling these particles are increased. These toxins, derived from nerve gas, affect your nervous system just as it does the mosquito’s.
Some mistakenly believe that fog kills mosquitoes for up to two weeks. The truth is that, once the fog settles, which is anywhere from a few minutes to a few hours after the truck goes by, there is no residual killing effect on mosquitoes. Soon, fresh adults will hatch to take the place of any mosquito that might have been dropped by the fog. Residual chemical should be washed from playground equipment, food products, birdbaths, etc., because the toxic effect is still there for humans and other animals – just not mosquitoes!
There is also the problem of resistance. A study in the North Fork in 2007 concluded that regular spraying resulted in mosquitoes that were immune to the spray. According to the study’s author, Malathion is rarely used anymore because Culex mosquitoes, the kind that carries WNV, readily develop resistance to organophosphates. He noted that calendar spraying is simply ineffective and only exacerbates the development of resistance.
The District has used permethrin in its fogging operations in recent years as an alternative to organophosphates. However, the EPA fact sheet on Permethrin says it is “highly toxic” to aquatic organisms and to honeybees. A 2007 report done in Paonia summarizing 108 peer-reviewed studies found significant human health effects from permethrin ranging from Parkinson’s to childhood brain cancers.
Experience has shown that a much more effective approach is to prevent mosquitoes from becoming adults. This requires much more time and effort – remember your trek through those boggy marshes at 6 am with the intrepid crew? And yes, it takes tax money. However, it is effective. We are actually getting benefit from our tax dollars and killing mosquitoes by the millions.
You are not smelling mosquito spray in the air this summer; but that does not mean that the District is doing nothing. In fact, the reports of mosquitoes with WNV are proof that the District is doing something. Without the trapping performed by the District, the County Board of Health would have no idea that WNV is in the North Fork. The District is finding it because they’re looking for it – in the mosquito pools – and not waiting until local hospitals report the disease in humans. Notably, there have been no reports of West Nile in humans since the District started its current style of “doing nothing.”
The District prefers to use non-toxic methods, mainly because they are actually effective. Spraying has an overall counter-productive effect: A false sense of protection coupled with the destruction of helpful predators, essential pollinators and other non-targeted species, including you.
To see what others have learned about mosquito spraying, just take a look at: https://sites.google.com/site/saynaytospray/