All our mammalian friends are replaced by domesticated giant insects! Man's best friend are now dog-sized hissing cockroaches, fireflies are lighteninglighting our houses and harvestmen are used for transport. Consider present day technology, no magic - but instead of our most common mammalian companions, I'm looking for giant sized insects to fill their roles. Do not consider feasibility of this increase in size - for all that matters insects just happen to grow as big as mammals.
Cattle is used for meat and milk production and as draught animals. Which species of insects, given a boost in size and several thousand years of domestication, could replace them? Would it be more than one? They don't have to produce real milk, but some other digestible fluid would be cool!