Hello; If you have done a literature search and weren't able to answer the question you will have to do a little behavioral experiment in which you test each chemical on free-flying butterflies that you are interested in.
The toxicity of at least some of these molecules might be a source of some concern. best regards, Jim Des Lauriers
Just do the GC-MS analysis of particular flower extract to find the chemical constituents. After that You can easily find which compound is acts as deterrent and which one is attractant.
Took a particular chemical (which were previously identified through GC-MS analysis) and simply soak in a cotton ball and offer it to the butterfly. If the fly is moving nearby then it would be a attractant. Repeat the process before standardization.