can't remember exactly, but it seems like the recommendations for grasshoppers are a dusting of plain flour (cements up their digestive systems) & maybe diatomaceous earth (sharp edges abrade their bodies).

You might post on the Organic Gardening Forum;
I'll bet they know more techniques!

there's a grasshopper killer called "viper"..i usually grow organic,but when i got invaded one year,i had to go to chemicals or lose everything in my greenhouse..i walked around the outside of a 48 ft greenhouse,spraying grasshoppers,and by the time i got to the starting point,i had piles of them kicking their last..really fast knockdown and kill.you'd have to actually spray the hoppers,but it sure works good!