QUESTION:

I have a farm and family center in central NY that has mosquitoes in the greenhouse, garden center, and some getting into the main store area. What would you recommend to do in a situation like this? I am not sure if fly zappers would work or if just the cold weather would take care of the problem, but they are asking us to deal with it. Please advise as to what we might be able to do.

ANSWER:

This is always a really tough demand on the part of customers - handing you the task of stopping flying insects from flying onto their property. Hopefully I can offer some worthwhile suggestions, and the first one is always to make certain of that identification. Are these really mosquitoes, or could they possibly be non-biting midges, crane flies, or some other similar fly? But, mosquitoes certainly are a possibility in your area, so we'll work with that assumption. Second, yes, cold weather is going to cause them rather suddenly not to be active anymore, but your customer is not likely to accept this solution if they think that you should have a magic wand in your pocket that eliminates the mosquitoes immediately. So, the question really is how to prevent these insects from coming onto this property and to prevent them from entering the store, and this is difficult.

Of course, we always look to the source. You can inspect the property itself, especially that garden center / greenhouse, to see if there are any breeding sources on site. Perhaps there are decorative fountains in place that contain water with mosquito larvae, catch pans under potted plants with water constantly in them, or any other standing water that would allow the mosquitoes to breed right there. If so, point it out to the customer and suggest ways to remedy the problem by eliminating the water. Then, move to the surrounding properties around this center and see what other local breeding sites may be nearby - ponds, creeks, low areas with water retention, waste areas with old tires, buckets, etc. Many of these could just be emptied of water while others might need to be treated with a larvicide if you are able to do so. Female mosquitoes generally do not fly very far from their breeding source, although some species are "capable" of traveling fairly long distances. But, the odds are that the mosquitoes at this garden center are coming from a local source.

So, do what you possibly can to reduce the numbers of mosquitoes that can visit this site and make sure they really are mosquitoes. Then, we have to ask what can be done to prevent or capture them as quickly as possible, and of course suggestions that work for homeowners are not appropriate for a retail store - wear repellent, long sleeves, keep doors closed, etc. Mosquitoes do not like air movement, so if this is a regular problem at this store they might consider the use of some sort of air door at entrances. Placed properly the air flow would either push the mosquitoes away from the doorway or just discourage them from even trying. Unfortunately, UV light traps of any kind (zappers or glue trap kinds) are not effective at attracting and controlling mosquitoes, and in fact are much more likely to kill many beneficial insects instead. Mosquito monitoring traps that use UV also use carbon dioxide, which is really the major attraction to a mosquito, along with some other interesting lures that may also enhance the draw to the trap. But, these are best used for monitoring and not control.

 

You might consider the application of residual insecticides as a "barrier" treatment while the store is not in operation. The treatments would be directed to places where the mosquitoes are likely to rest during the daytime, which is often shaded places such as under the eaves, within shaded cavities, or anyplace where there is semi-darkness and little human activity at that time. Around homes barrier treats have been shown to provide very good relief from biting mosquitoes for 2 weeks or more. The use of pyrethrum mists or fogs could also drop the population of adult mosquitoes but it has some drawbacks. First, you probably would not want the misting occurring while customers are present. There are just too many negative attitudes about being exposed to any kind of (and say this with dread in your voice) PESTICIDES!! You could fog the garden area at night, but pyrethrum lasts only a short time, so if more mosquitoes can come to the site the effectiveness is very short, and you would have to do this every day to keep the effectiveness going.

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