There really are no temperature restrictions for applying Bifen IT. It can be applied at any time of day as long as you are not expecting any rain for at least 24 hours.
There is not an expiration date printed on the Bifen IT bottle. This product will last for 3-5 years from the date of purchase if kept sealed and stored at room temperature.
Adding a surfactant to Bifen IT outdoors does help the product adhere and increase effectiveness during the residual period.
Bifen IT and Termidor should not be mixed for termite control. Bifenthrin products used to be considered a good form of termite treatment, but bifenthrin acts as a repellent and now a days almost all professional termite companies are using non-repellents, such as Termidor SC. We have a great article called How To Do A Termite Treatment that explains how to perform a treatment using a non-repellent termiticide.
Yes, Bifen IT is labeled for silverfish and will do a great job helping to eliminate them. Be sure to spray in all of the cracks and crevices where silverfish are known to harbor for best results. You will mix 1 oz per gallon of water per 1,000 sq ft. and it can be applied every 30 days on the outside of the structure and every 90 days to the indoor cracks and crevices. Keep in mind that these pests frequent humid areas such as bathrooms and stored paper goods like files and wallpaper, so non-chemical steps to correct those conditions will help eliminate this pest.
Bifen IT is labeled for bedbugs but according to the product label it should not be the only product that you use for bedbug control. Most folks purchase and use our Bedbug Kits for bedbug control as they come with all of the products that will be needed. Please take a few moments to review our treatment article on How to Get Rid of Bedbugs for a successful program.