I read your internet article on gnats. We live in Indianapolis, IN. Within the last month we have an infestation of gnats. They don't seem to bite. Can you help suggest how we can get rid of them?
Many Thanks, G.H.
If you read through our GNAT CONTROL ARTICLE, you'll see this pest is commonly a problem out in the yard. But as fall turns to winter, many home owners will find them active inside the home. To make the problem more difficult to treat, there is a wide range of gnats which will thrive all winter inside the average home so it can sometimes be frustrating trying to get rid of the active adults and solve the problem. Fortunately we've narrowed it down to a few key locations you should focus on if you have any in your home.
One of the most common sites for gnats during the winter is the soil of any house plants. Here they'll land to lay eggs and keep their cycle current. But don't expect to see any hanging around your plants; they'll rarely go there spending 99.9% of their time out and about in the home. But when it's time for females to lay eggs, potted plants and the soil in the pots are one of the most common locations they'll seek.
So if you have potted plants in the home, start with them. The simplest treatment for them is to mix up some VEGETABLES PLUS PERMETHRIN and drench the soil of the plant like you're watering the plant. This material is odorless and safe enough to spray on vegetables and fruit so it's fine for house plants. A good dose to the soil will permeate down and throughout the dirt rendering it impossible to be used for breeding gnats. If you prefer something organic, go with the MULTI PURPOSE INSECT KILLER. Treatments should be done the same way but since it's organic, it won't last nearly as long so repeat treatments weekly till you're sure all the gnats are gone.
The second spot gnats seem to love is the drain of any sink, shower or tub. This is especially true if the sink has a "sinkerator". Garbage disposals commonly harbor tons of waste and food in areas which are hard to clean. People routinely pour bleach, ammonia and other cleaning compounds down the sink thinking this will help but in most cases it's a waste of time and money. As food and other organic matter decompose, they tend to buildup as a slimy film along the walls of drain lines and other spaces. And it's these slimy buildups which gnats will use to both feed in and remain protected from cleansing agents. This makes it extra tough to control them in this area.
Fortunately GENTROL AEROSOL is labeled for use down drains. It's easy to use and can be sprayed directly into sink drains. Gentrol is a juvenile growth hormone and not an adulticide so it won't actually kill anything. But it will prevent the young fly larvae from developing so they won't be able to fully mature. That means they won't become reproducing adults and when it comes to breaking the cycle of gnats, this is critical. The only shortcoming of this treatment is you won't get the normal long term protection from Gentrol when used down the drain. Typically it can several months but down the drain it's life will be much shorter. The slime buildup will work against Gentrol just like everything else so you'll need to use it frequently to get the problem solved for good.
Now if you don't have either of the two locations mentioned above, you might have to do some detective work to isolate the gnat breeding ground. Keep in mind they like moisture and need some kind of organic matter. Besides sinks and potted plants, gnats will take advantage of kitty litter, garbage pails, recycling bins, leaky roofs, condensation around windows, leaky showers, washing machine drain lines, ac water pumps that are harboring water, sump pumps, septic tanks and other places where water or some kind of organic matter can remain warm during the winter months. Most of these areas can be treated with the Gentrol and over time, it alone can solve the problem. But if you have a lot of adults flying around, use AQUACIDE for quick control. Designed for flying insects, it's safe enough to use as needed but it won't target the gnats where they're nesting so in the long run, Aquacide generally won't solve problems. But it can help. The organic option for the adults is the FLYING INSECT KILLER which would be used the same way as the Aquacide.
Here are direct links to the information and products listed above:
Gnat Control Article: http://www.bugspray.com/article/gnats.html
Vegetables Plus Permethrin: http://www.bugspray.com/catalog/products/page1815.html
Multi Purpose Insect Killer: http://www.non-toxic-pest-control.com/concentrates/multi-purpose-insect-killer-24-oz
Gentrol Aerosol: http://www.bugspray.com/item/gentrol_aerosol.html
Flying Insect Killer: http://www.non-toxic-pest-control.com/aerosols/flying-insect-killer-14-oz