I have a friend who thinks that the scene in “The Good Shepherd” directed by Robert DeNiro (2006) where the CIA destroys a central American coffee plantation by dropping locusts on it is absolutely absurd. (It is a fictionalized movie) However, I have seen stories on the History channel about the bizarre WWII plan to drop bats with explosives tied to them so that they would fly into Japanese attics,explode and scare people so I know the good people at the intelligence agencies have historically had a wonderful penchant for seemingly harebrained ideas. However, I am not sure how harebrained they really were. I understand the main problem with the bat plan was there was no cost effective way to load up bats with explosives other than by hand which would take forever and cost too much money - (hence the harebrained). I assume many bats wouldn’t make into Japanese homes as well, but in any case - What do the millions think of the locust plan? Totally ridiculous? Maybe it is in the same category as the bat idea, hard to implement, but not impossible… ?? What do you all think? Any comments on the bat plan are also appreciated and will not be taken personally. 
The bats were carrying incendiary bombs:
Yes, it’s completely absurd. You’d need a lot more than million locusts. Swarms measure around 1000 individuals/metre. So unless your coffee plantation consists of just a dozen or so trees you’ll need tens or hundreds of millions of locusts.
Locusts aren’t a species. Locust are grasshoppers. They become locusts when they swarm, but they only swarm under specific conditions. The *simplest[/I way to] collect a million locusts is to capture a million locusts from a wild swarm. The alternative sin contrast are silly.
So assuming you get your million locusts, then what? You release them from a plane, they disperse on the winds and you get a density much reduced fm the initial. But let’s say that you’ve compensated for that by collecting billions of locusts and manage to maintain high densities.
So your locust land. But locusts aren’t lawnmowers. They discriminate in what they eat, and when they are in low numbers in food rich environments they are very discriminating. They begin to feed on the coffee, realise that it is toxic and move to other plants. After all there’s plenty of food in the area, and locusts by definition are migratory. End of problem.
The whole scenario is ridiculous. It would make more sense to breed one of the numerous pests that, you know, actually eat coffee and aren’t poisoned by it.
Locusts are a problem in their natural habitats because they build up to truly huge numbers, tens of billion of insects. You can’t possibly fly such number sin by plane, and in smaller numbers the swarms rapidly disperse, breed and die.
The purpose of the bat-carried incendiaries was not to scare people, but to burn down cities more efficiently. During the war, Japanese cities were quite susceptible to fire bombing because of the large amount of wood used in their construction. The bat-bomb was thought up by a civilian (not an intelligence agency), who went on to work for the military, as a way to start more fires over a larger area (per bomber) than with typical incendiary bombs. It was abandoned not due to the difficulty of loading the critters, but because of the development of the atomic bomb.
What if we drop the requirement that it is a coffee plantation, and assume it is a plantation that crickets like to eat. And let’s say you manage high densities of locusts. Can this create a problem? Assuming they are in a good eating area, and taking into account their reproductive cycle, could it work?
I haven’t seen the movie, so maybe there’s an obvious answer to this, but: Why locusts anyway? Why not napalm, or agent orange? Or even land mines, so they wouldn’t be able to harvest the coffee?
It would be rather difficult to confuse napalm or land mines for natural phenomena. Plausible deniability and so forth.