Q. Why do I see Volusia County Mosquito Control trucks driving through my neighborhood, with lights flashing, and I see nothing sprayed out?
A. The equipment used by Volusia County Mosquito Control to control adult mosquitoes emits an ultra-low-volume (ULV) spray of extremely small spray droplets. The volume of spray, or application rate per acre, is also extremely small. A typical rate per acre, whether via truck or aerial equipment, is about one ounce of insecticide or less -- about a shot glass of material per football field.
Q. Why don't you fog on a regular basis?
A. First, please be aware that we need to separate "fogging" from modern-day applications, or ULV.
In the past, insecticides were sometimes mixed with oil and heated to create a "cloud" or "fog." This methodology is not commonly practiced today and if it is, it is more likely to be from a hand-held unit. Volusia County Mosquito Control does not fog.
Volusia County Mosquito Control deploys ULV applications of several adulticides. While there are a few things that separate the two methodologies, chief among them is lack oil-mixing. ULV products are used "neat" -- this allows for and accounts for an ultra-low-volume of insecticide to be used per acre of treatment area.
Second, a professional IMM (integrated mosquito management) plan as it exists in Volusia County and across Florida sprays for mosquitoes only when surveillance has indicated that mosquito levels exceed baseline population numbers.
Areas with mosquitoes that exceed this baseline are sprayed as required to reduce biting annoyance. Often, this can be achieved from existing roadways with truck-mounted ULV equipment. When infestations are more widespread, it may be necessary to treat from the air via helicopter or airplaine.
Q. Why don't you do all your spraying by air, instead of using trucks?
A. Not all nuisance populations are widespread enough to justify aerial missions. The extent and severity of the infestation, as identified and delineated through Volusia County Mosquito Control surveillance, determines the operational response. Trucks allow for more "prescriptive" applications; when it is necessary to cover more completely an infested aera -- more than can be achieved via roadways -- an aerial application is warranted.
Q. Why do you spray for mosquitoes when folks are out and about?
A. Moquitoes are primarily most active and seeking a blood meal at dusk and dawn. This period of activity has evolved over thousands of years, partly due to the fact that this is when mammals, including humans, are available as a food source.
Volusia County Mosquito Control typically starts ground ULV spray operations an hour after sunset and attempts to complete all operations, whether by ground or air, before sunrise. We are usually finishsed with ground operations before midnight.
At times, people are still active and outside after dusk when our spray missions are initiated. If our drivers see folks out and about, they will turn off the spray as they pass.
Q. Why doesn't nature take care of our mosquito problem?
A. Unfortunately, there are too many mosquitoes for nature to contend with -- at least insofar as reducing them to tolerable levels. Birds, bats, dragonflies and frogs eat their fair share, but they simply don't consume enough of the population to make a dent as a control agent.
That's where control agencies come into play. Volusia County Mosquito Control has an IMM program that includes the following:
Q. Can I be notified of a ULV spray application scheduled to take place in my neighborhood?
A. Absolutely! Volusia County Mosquito Control maintains a notification or call list of individuals in our county who must take precautions when sprays are used. Simply contact us to be placed on the call list and we will notify you before a spray event.
Q. What is encephalitis, and which mosquitoes transmit West Nile virus?
A. In severe cases, encephalitis results in an inflammation of the brain and spinal cord. More than 40 species of mosquitoes have been found to be infected with West Nile virus (WNV) in the United States. Many of these mosquito species feed only on birds, thus contributing to a cycling of the virus among avian populations.
Other mosquito species feed on birds and then feed upon mammals, including humans. These are called "bridge vectors" because they serve as a bridge for the virus to travel from birds to a mammalian host -- sometimes human. Control measures for each type of mosquito may vary, which is one of the reasons surveillance is critical.
Q. How can I protect myself?
A. Decreasing the probability and number of mosquito bites helps. Preventive measures include avoiding outdoor activities after dark when the mosquitoes are most active, wearing protective clothing (long sleeves and pants, etc.), and using repellents that contain DEET as their active ingredients. Click here for more information.
In 2005, the Centers for Disease Control began recommending two new active ingredients as safe, effective repellents:
Q. What about backyard misting systems, bug-zappers and ultrasonic devices? Are they any good?
A. Misters emit chemical on a schedule (timer) and may needlessly broadcast pesticide into the environment regardless of mosquito activity. An IMM program emphasizes an integrated approach based on surveillance and knowledge of the targeted mosquito species; that way, a variety of vulnerabilities can be exploited by the tools the surveillance and control agency has developed.
Sorry, bug-zappers and ultrasonic devises just don't cut it if you're looking for effective relief. Research done by investigators at the University of Notre Dame showed that mosquitoes comprised merely 4.1 to 6.4 percent of the daily catch over two mosquito seasons. More importantly, no significant difference in the number of mosquitoes was found in yards with or without bug-zappers. Additionally, the number of non-pest insects comprised the vast majority of the bug-zappers' catch. Many of these insects are beneficial predators on other insect pests, including mosquites.
At least 10 studies in the past 15 years have unanimously denounced ultrasonic devices as having no repellency value whatsoever. Tests have shown that sound generators capable of a wide range of frequencies are ineffective in repelling mosquitoes. The fact is that these devices just do not work -- marketing claims to the contrary!
For other mosqutio facts and fiction, visit the American Mosquito Control Association's website at www.mosquito.org. The site also provides links to many other mosquito-related sites of interest.