Aug 7, 2011 – Mosquitoes and That Vacation Experience
QUESTION:
Presently fogging is being done for mosquitoes and flies, but this doesn't seem to be that effective. What else can we do to eliminate this problem? What is the difference between a Mist Blower and a Fogger, and how effective are they? Is it safe to fog for mosquitoes at a hotel when it is occupied with guests?
ANSWER:
It is probably only a matter of semantics when you hear of a mist blower versus a fogger, but nearly all mechanical "foggers" emit droplets in the ULV range of 5-20 microns, meaning a very tiny droplet that stays airborne for awhile and drifts well with any wind. A "mist" blower may refer to a fogger that emits larger droplets, which is normally the basis for referring to it as a mist rather than a ULV fog. Again, this may just be how a product is named, but the larger droplets of a mist will settle to the ground or other surfaces more quickly and thus not be carried as far by any breeze. Generally speaking, when you are hoping to achieve a kill of adult mosquitoes the ability for the droplets to drift awhile to contact more air space and more surfaces is an advantage. It simply covers more area and stays in the air longer to give the potential to contact more flying insects.
Mists and fogs are effective at knocking down adult mosquitoes that are present at that moment, but no residual effect is left behind. The pyrethrum used in foggers is essentially contact only, no residual, and while it does give definite relief from biting mosquitoes it will not prevent new adult mosquitoes from re-entering the area shortly after. However, it does give that reduction of the biting adult insects, so it has some benefit. Combine this with barrier treatments where you spray foliage and other surfaces where the adult mosquitoes will spend time resting and you get a much longer effect in reduction of the insects.
Is it "safe" to fog while guests are present? Well, this is a really good question, and my answer would be that you should take every step necessary to fog ONLY when no one is present who will be contacted by the fog. Even though pyrethrum is a natural material and has no no residual and has a relatively low toxicity, it still is a TOXIC material, and to many people this means it would be an unacceptable thing to be exposed to. There are people who either are sensitive to pyrethrum or believe they are, and if they were walking outside when a cloud of pesticide passed by them all sorts of bad things could occur. Pyrethrum also has a very noticeable odor, and even this could result in complaints from guests that they were feeling ill, so I suggest that the applications be done only when guests are not outside in the area of the treatment. You also need to be aware of wind direction and speed to ensure the fog goes where you want it to go.
View past Ask Mr. Pest Control questions.
Presently fogging is being done for mosquitoes and flies, but this doesn't seem to be that effective. What else can we do to eliminate this problem? What is the difference between a Mist Blower and a Fogger, and how effective are they? Is it safe to fog for mosquitoes at a hotel when it is occupied with guests?
ANSWER:
It is probably only a matter of semantics when you hear of a mist blower versus a fogger, but nearly all mechanical "foggers" emit droplets in the ULV range of 5-20 microns, meaning a very tiny droplet that stays airborne for awhile and drifts well with any wind. A "mist" blower may refer to a fogger that emits larger droplets, which is normally the basis for referring to it as a mist rather than a ULV fog. Again, this may just be how a product is named, but the larger droplets of a mist will settle to the ground or other surfaces more quickly and thus not be carried as far by any breeze. Generally speaking, when you are hoping to achieve a kill of adult mosquitoes the ability for the droplets to drift awhile to contact more air space and more surfaces is an advantage. It simply covers more area and stays in the air longer to give the potential to contact more flying insects.
Mists and fogs are effective at knocking down adult mosquitoes that are present at that moment, but no residual effect is left behind. The pyrethrum used in foggers is essentially contact only, no residual, and while it does give definite relief from biting mosquitoes it will not prevent new adult mosquitoes from re-entering the area shortly after. However, it does give that reduction of the biting adult insects, so it has some benefit. Combine this with barrier treatments where you spray foliage and other surfaces where the adult mosquitoes will spend time resting and you get a much longer effect in reduction of the insects.
Is it "safe" to fog while guests are present? Well, this is a really good question, and my answer would be that you should take every step necessary to fog ONLY when no one is present who will be contacted by the fog. Even though pyrethrum is a natural material and has no no residual and has a relatively low toxicity, it still is a TOXIC material, and to many people this means it would be an unacceptable thing to be exposed to. There are people who either are sensitive to pyrethrum or believe they are, and if they were walking outside when a cloud of pesticide passed by them all sorts of bad things could occur. Pyrethrum also has a very noticeable odor, and even this could result in complaints from guests that they were feeling ill, so I suggest that the applications be done only when guests are not outside in the area of the treatment. You also need to be aware of wind direction and speed to ensure the fog goes where you want it to go.
View past Ask Mr. Pest Control questions.
