Q.How Many Applications Of Spinosad, Beginning In Early Spring, Are Needed To Thoroughly Kill Iris Borers ? Your Article Mentions On
ly two – is that sufficient for the season? I live in southeastern PA and have a returning borer issue every year. I have been using Bonide’s Captain Jack Deadbug product for awhile, but perhaps not with the best timing or frequency.I also have dug up and thrown out infected plants.

Certified GKH Gardening Expert
Pesticides contain instruction pamphlets on the bottle. These should be read, thoroughly, and understood before using the product.
Different plants have different requirements, but be aware that tree borers, once inside the tree and established, can be near impossible to get rid of.
This article will give you more information on the subject of borers:
https://www.gardeningknowhow.com/ornamental/trees/tgen/tree-borer-insects.htm