you are comparing apples with oranges, so to speak. the irradiated, pesticided, Genetically-Modified-Organisms fruit is not necessarily recognized as "food" by the critters so they stay away.
as for on the vine or off, doesn't matter. the produce continues to emit frequencies. thus healthier produce emits a stronger frequency that tells the insects to stay away, not so healthy produce emits the signal that tells them to come eat. there is no difference between on the vine or off the vine, the same process is taking place.
this is why high brix produce does not rot as quickly as low brix produce does.
(and come on you didn't know that about human flesh emitting radiation did you? haha!)