Scientists have different methods of figuring out the best way to kill bugs. There's the standard "observe their behavior in a lab" and then there's the fly death chamber, which, you may not be surprised to learn, researchers pump full of new insecticides to see how effective they are at killing the flies.
A perhaps more civilized, though no less brutal method, are the "poison sandwiches." Researchers cut cute little disks of mulberry leaves, the favorite snack of silkworms, and cover them with poison dust. By measuring the weight of the silkworm and how much of the sandwich it ate before keeling over, scientists can determine exactly how much poison it takes to kill one.
Read the full story in New Indian Poison Aids War on Bugs