Welcome to the Forum Lucky Flowers! Glad you found us.
There is a microbial insecticide call "Nosema Locustae" that is supposed to work within 2-3 weeks of using it.
Another option is to cover your plant with garden or remay cloth, or a row cover.
There is also a product available call Semaspore Bait that is a biological control, and is not supposed to be harmful to other species.
I have not tried any of these, as it is rare for us to even see a grasshopper, let alone hoards of them, so I can't tell you whether any of them work. Those are the only treatments I was able to find in all my literature.
Best of luck! Feel free to stop back with any further questions or problems, or just to chat. Let us know how you make out!