One of my favorite bits from James Scott’s Seeing Like a State:
While doing fieldwork in a small village in Malaysia, I was constantly struck by the breadth of my neighbors’ skills and their casual knowledge of local ecology. One particular anecdote is representative. Growing in the compound of the house in which I lived was a locally famous mango tree. Relatives and acquaintances would visit when the fruit was ripe in the hope of being given a few fruits and, more important, the chance to save and plant the seeds next to their own house. Shortly before my arrival, however, the tree had become infested with large red ants, which destroyed most of the fruit before it could ripen. It seemed nothing could be done short of bagging each fruit. Several times I noticed the elderly head of household, Mat Isa, bringing dried nipah palm fronds to the base of the mango tree and checking them. When I finally got around to asking what he was up to, he explained it to me, albeit reluctantly, as for him this was pretty humdrum stuff compared to our usual gossip. He knew that small black ants, which had a number of colonies at the rear of the compound, were the enemies of large red ants. He also knew that the thin, lancelike leaves of the nipah palm curled into long, tight tubes when they fell from the tree and died. (In fact, the local people used the tubes to roll their cigarettes.) Such tubes would also, he knew, be ideal places for the queens of the black ant colonies to lay their eggs. Over several weeks he placed dried nipah fronds in strategic places until he had masses of black-ant eggs beginning to hatch. He then placed the egg-infested fronds against the mango tree and observed the ensuing week-long Armageddon. Several neighbors, many of them skeptical, and their children followed the fortunes of the ant war closely. Although smaller by half or more, the black ants finally had the weight of numbers to prevail against the red ants and gain possession of the ground at the base of the mango tree. As the black ants were not interested in the mango leaves or fruits while the fruits were still on the tree, the crop was saved.
This successful field experiment in biological controls presupposes several kinds of knowledge: the habitat and diet of black ants, their egg-laying habits, a guess about what local material would substitute as movable egg chambers, and experience with the fighting proclivities of red and black ants. Mat Isa made it clear that such skill in practical entomology was quite widespread, at least among his older neighbors, and that people remembered something like this strategy having worked once or twice in the past. What is clear to me is that no agricultural extension official would have known the first thing about ants, let alone biological controls; most extension agents were raised in town and in any case were concerned entirely with rice, fertilizer, and loans. Nor would most of them think to ask; they were, after all, the experts, trained to instruct the peasant. It is hard to imagine this knowledge being created and maintained except in the context of lifelong observation and a relatively stable, multigenerational community that routinely exchanges and preserves knowledge of this kind. [Chapter 9]