Jun 21, 2012 – Mosquitoes Outdoors

QUESTION:

What is the best thing on the market to repel mosquitoes on land which adjoins lake front property?

ANSWER:

I don't know that repelling the adult mosquitoes is really an effective solution outdoors, other than repellents applied to the people who are active in this area. You can find plenty of advertisements for ultrasonic repellers that experts will tells us are just frauds. There also are claims that citronella candles and plants and other devices will repel mosquitoes, but these may have some effect only on a very, very local area immediately near that candle or emitter. Fogging with pyrethrum will definitely have a repellent effect on the adult mosquitoes, as well as kill any of them contacted by the mist, but this will be a very short term effect, and once the pyrethrum as dissipated more adult mosquitoes can re-enter the area without harm. 

Two possible choices, and probably only one that is acceptable. The best mosquito control is to attack the source, meaning the habitat where the mosquitoes are coming from, which is the aquatic site where the larvae are developing. By applying long-lasting larvicides that prevent adult mosquitoes from being created you prevent the presence of the annoying stage of the insect. However, this is probably impractical for a lake, as it is too large a site to deal with and probably is not under the control of any individual homeowner. In a sense you have to accept that if the lake is the breeding site there are going to be adult mosquitoes. There may, however, be some breeding sites directly on the property of your customer that could be eliminated - standing water or some kind -  that would at least reduce the overall problem. 

The most effective service you may be able to offer in this case might be a "barrier treatment" using a labeled residual insecticide. Many of the pyrethroids are labeled for mosquito control and can be applied to shrubbery, trees, under the eaves, and to other resting areas where adult mosquitoes will sit for many hours each day. University tests have shown some pretty good results lasting several weeks or more with major reduction of adult mosquitoes on a property. This is probably best used when some outdoor event is planned, applying the materials the day before to get the kill of the mosquitoes for the best effect. 

Mosquito misting systems are also a possible option, but some states do restrict how these can be used. These are permanent installations of misting nozzles and a central tank of pyrethrum that is emitted at a timed interval. The pyrethrum mist then rapidly kills any adult mosquitoes that may be exposed to it at the time of the misting. Pyrethrum also is very repellent to flying insects, so some level or repellency may be achieved for awhile afterward. 


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