Bifen IT has a residual of 90 days indoors and 30 days outdoors. Repeat application should only take place if there are signs of renewed insect activity and must not exceed one application per 7 days.
Please view the product label for listed insects and more information.
When applying Bifen IT for fall webworms or other ornamental pests, use 0.125-0.25 ounces of concentrate per 1,000 square feet, or 5.4-10.8 oz. per 100 galons of water for high volume applications. See the product label for complete application instructions.
You should contact your local cooperative extension office to find out the best time to start spraying a product like Bifen IT in your region. They are more familiar with the timing of insect activity in your area. We can say that it should be applied monthly through the beetles active months.
We would recommend using Hi Yield Indoor/Outdoor Permethrin 10% Insecticide. It is safe for use on edibles and is labeled for mosquitoes. The mixing ratio is 1-3 oz. per 4 gallons of water. This will treat approximately 4000 square feet. This can also be used in your lawn for mosquitoes as well.
Bifen IT typically only take 1 hour to completely dry on a surface and will hold up very well in the rain, but you should have a minimum of 6 hours between your applicaton and rainfall or irrigation. Bifen IT is rainfast 6 hours after the application, and is recommended to be used with a pump sprayer.