I have numerous cicadas in all trees. Is this the only known repellant available?
We have two insect repellents that work well on most any insects including cicada's. These products won't kill anything; they're only meant to keep annoying and invasive pests away. Used mostly for mosquitoes, gnats, wasps and other pests that commonly invade homes, these same products can be used to chase away cicada's.
The first one is the MOSQUITO REPELLENT. It comes in a ready-to-spray jug which means all you need to do is hook it up to your garden hose and you're ready to use it. The power of the water pressure for your home is what will propel it out and most homes supply a strong enough water flow so the spray can reach quite high. Be sure to get some material on as much of the tree as possible. And focus your attention to the trees they seem to like. Repeat when they return; most people will have to treat 2-3 times per season depending on the cycle for any particular year. And most applications will last 1-3 weeks.
The second option is a concentrate. NBS INSECT REPELLENT is mostly used for pests like wasps, carpenter bees and other invasive insects on the home. The most popular way to use it is to add some to your paint or stain when finishing the exterior of the home or any other structure you want to keep pest free. It can also be mixed with water and sprayed out over these same areas. It's perfectly safe for plants and when used on trees and shrubs and bushes where cicada's like to rest, it will effectively repel them for 2-4 weeks. Again, retreat as needed and mix it up at the rate of 3 oz per gallon. Most people will use it in a HOSE END SPRAYER so they're able to reach quite high where cicada's like to roost.
Here are direct links to the information and products listed above: