Many societies have and continue to practice entomophagy, and many environmental activists promote the consumption of insects as an environmentally friendly alternative to traditional meat. It is relatively cheap to raise insects on an industrial scale with modern technology, but would it be feasible for people at a much lower level of technology?
Preconditions:
The primary reason they raise insects is that most of the large animals are dangerous to consume due to a neurotoxin that is accumulated in their flesh.
Tech Level: Think Iron Age Sub-Saharan Africa. So medieval Africa not medieval Europe. This means you’ve got iron tools, some kingdoms and a severe lack of good beasts of burden. They use hoe farming rather than the plow
Climate: Tropical Rainforest transitioning to Savannah. Think African Great Lakes Region
Other sources of food: They grow several kinds of tubers and fruit trees, along with fishing and hunting a very select few species.
My ideas for how they farm the insects:
Piles of rotting wood to raise grubs and termites
Slaughter some of the toxic animals to feed to carrion beetles and flies (Maybe to get the bones or something)
So would it be feasible for a preindustrial society in a tropical climate to farm insects?