Jul 6, 2011 – Bop The Biter
QUESTION:
What are the correct and effective preventive measures to minimize mosquitoes and blood- sucking flies activity around a given structure?
ANSWER:
Controlling flying insect pests can be one of the toughest things we do, especially if the focus has to be on the adult insect. We can concede that we cannot stop a fly from flying, and if there is some food attraction (in this case humans) these pests will head toward where we do not want them. I like to use my fingers to count on, so our choices for controlling biting flies are (1.) killing them after they enter the property we are managing (2.) killing them as adult flies before they reach the property (3.) controlling them in the larval stage before they become the biting adult insect. I suppose we also could toss in preventing them from biting, such as the use of long sleeves and repellents, and on a private property this advice may be useful to a homeowner, but on a commercial property such as a hotel it is not of any value. You are not going to get all guests at a nice hotel to put on repellent and long sleeved shirt and pants when they want to lay around the pool.
Larval control is the ideal method if it is possible. If you prevent the production of flying, biting adult flies you save yourself all that time and effort swattting at the adults. For mosquitoes this is very possible, as they must breed in standing water and the adult mosquitoes generally will be problems fairly close to where they grew up. Identifying all of these sources around that property and either draining the water away or treating it with a larvicide can be highly effective. You can educate customers to keep standing water eliminated where possible, such as clogged rain gutters, empty containers on the property with rainwater in them, tarps and other covers that hold water, depressions in the soil that can be filled, etc. They can manage bird baths, pools, ponds to keep water clean. And, you or they can use labeled IGR's or bacterial products in the water that must remain to kill the larvae.
For other biting flies source control like this may not be practical. No-see-ums, sand flies, horse and deer flies - these all breed in any wet setting such as leaf litter, wet soils, etc., and controlling these larvae at their breeding sites may be impossible. Here you are stuck with dealing with biting adults. None of these flies, mosquitoes included, is highly attracted to UV light. Instead it is CO2 that is the primary attraction since this indicates a warm blooded host animal is present. Mosquito traps are one option you can consider, and while they will not eliminate mosquitoes they do help cut down the overall numbers.
Another effective option for mosquito adults is the use of barrier treatments, applying residual insecticides to the places you expect the adult mosquitoes to rest. Since all insects have to rest somewhere every day, and perhaps for much of the 24 hour period, if you can have a contact insecticide on those surfaces you will kill the adult flies. This may be vegetation such as shrubs or trees, may be within out-buildings such as sheds or pet houses, or under the eaves of the roofline around the structure. Some of the pyrethroid insecticides have been tested for this, and up to 3 weeks of good relief from biting adult mosquitoes has been the result.
There also is fogging with pyrethrum to kill adult insects that are present. This does a very good job of killing any flying insects that happen to be present at the time the fog is released, but pyrethrum leaves no residual, so you can plan on having more of the insects moving back into the treated area right away if the breeding sources are still producing them. However, you will definitely get some relief for awhile with fogging. On a small scale the "misting" products can extend this relief. These are permanently attached to a structure and on a programmed interval they release a timed amount of pyrethrum mist. Numerous nozzles can be used to provide this over a wider area to enhance the effect. Some regulatory agencies are concerned about misting devices, probably because they are used quite often around homes with no ability to control where the mist travels once emitted, and a neighbor may object to having their yard treated too.
If this is a private home you have some hope of educating the customers to wear long sleeves and long pants during those periods outdoors when biting flies will be present. You can strongly encourage the use of repellents, and new repellents are coming into the market to offer alternatives to DEET, which long has been the product of choice for effective and extended repellency. You can evaluate the home to ensure all windows are screened, doors closed or screened, and no other obvious entry points are present to allow biting flies to enter. Where these insects are a real problem you also can encourage the use of mosquito netting at night.
It is the use of these many options altogether that begin to put a dent in the problem, rather than relying on a single option that does only part of the job.
View past Ask Mr. Pest Control questions.
What are the correct and effective preventive measures to minimize mosquitoes and blood- sucking flies activity around a given structure?
ANSWER:
Controlling flying insect pests can be one of the toughest things we do, especially if the focus has to be on the adult insect. We can concede that we cannot stop a fly from flying, and if there is some food attraction (in this case humans) these pests will head toward where we do not want them. I like to use my fingers to count on, so our choices for controlling biting flies are (1.) killing them after they enter the property we are managing (2.) killing them as adult flies before they reach the property (3.) controlling them in the larval stage before they become the biting adult insect. I suppose we also could toss in preventing them from biting, such as the use of long sleeves and repellents, and on a private property this advice may be useful to a homeowner, but on a commercial property such as a hotel it is not of any value. You are not going to get all guests at a nice hotel to put on repellent and long sleeved shirt and pants when they want to lay around the pool.
Larval control is the ideal method if it is possible. If you prevent the production of flying, biting adult flies you save yourself all that time and effort swattting at the adults. For mosquitoes this is very possible, as they must breed in standing water and the adult mosquitoes generally will be problems fairly close to where they grew up. Identifying all of these sources around that property and either draining the water away or treating it with a larvicide can be highly effective. You can educate customers to keep standing water eliminated where possible, such as clogged rain gutters, empty containers on the property with rainwater in them, tarps and other covers that hold water, depressions in the soil that can be filled, etc. They can manage bird baths, pools, ponds to keep water clean. And, you or they can use labeled IGR's or bacterial products in the water that must remain to kill the larvae.
For other biting flies source control like this may not be practical. No-see-ums, sand flies, horse and deer flies - these all breed in any wet setting such as leaf litter, wet soils, etc., and controlling these larvae at their breeding sites may be impossible. Here you are stuck with dealing with biting adults. None of these flies, mosquitoes included, is highly attracted to UV light. Instead it is CO2 that is the primary attraction since this indicates a warm blooded host animal is present. Mosquito traps are one option you can consider, and while they will not eliminate mosquitoes they do help cut down the overall numbers.
Another effective option for mosquito adults is the use of barrier treatments, applying residual insecticides to the places you expect the adult mosquitoes to rest. Since all insects have to rest somewhere every day, and perhaps for much of the 24 hour period, if you can have a contact insecticide on those surfaces you will kill the adult flies. This may be vegetation such as shrubs or trees, may be within out-buildings such as sheds or pet houses, or under the eaves of the roofline around the structure. Some of the pyrethroid insecticides have been tested for this, and up to 3 weeks of good relief from biting adult mosquitoes has been the result.
There also is fogging with pyrethrum to kill adult insects that are present. This does a very good job of killing any flying insects that happen to be present at the time the fog is released, but pyrethrum leaves no residual, so you can plan on having more of the insects moving back into the treated area right away if the breeding sources are still producing them. However, you will definitely get some relief for awhile with fogging. On a small scale the "misting" products can extend this relief. These are permanently attached to a structure and on a programmed interval they release a timed amount of pyrethrum mist. Numerous nozzles can be used to provide this over a wider area to enhance the effect. Some regulatory agencies are concerned about misting devices, probably because they are used quite often around homes with no ability to control where the mist travels once emitted, and a neighbor may object to having their yard treated too.
If this is a private home you have some hope of educating the customers to wear long sleeves and long pants during those periods outdoors when biting flies will be present. You can strongly encourage the use of repellents, and new repellents are coming into the market to offer alternatives to DEET, which long has been the product of choice for effective and extended repellency. You can evaluate the home to ensure all windows are screened, doors closed or screened, and no other obvious entry points are present to allow biting flies to enter. Where these insects are a real problem you also can encourage the use of mosquito netting at night.
It is the use of these many options altogether that begin to put a dent in the problem, rather than relying on a single option that does only part of the job.
View past Ask Mr. Pest Control questions.
