I think I've seen some discovery channel special about locusts or pests or something. If I am remembering correctly, they provide a surplus of food for birds at certain times, maybe during migration or breeding time or something.
It could become a counter-productive strategy, if we limit the swarming of locusts, which will limit the population of birds that prey upon the locusts... maybe causing an even larger population of locusts.
I'm sure things like that will be thought out before initiating any attempting to control the populations. Nature is a very sensitive thing, in regards to controlling it, we have been selfish in the past and thought of preserving humanity before preserving the entire environment.