I don't think he's saying that a single species of insect will have specialists in many different roles. I think he's saying that there are millions of species

I don't think he's saying that a single species of insect will have specialists in many different roles. I think he's saying that there are millions of species of insects and each species usually specializes in one thing so that they can survive in a specific environmental niche. I don't think specialization by humans is bad, but I agree that specialization can go too far sometimes. If the person being paid to monitor a tank of fluorine loses the ability to do their own laundry or hold a conversation because they are spending so much of their time developing fluorine tank monitoring skills it's kind of a waste. Part of the human experience is learning and doing lots of different things. Even if our economy rewards hyper-specialization that doesn't mean that a person's entire life has to be focused on their hyper-specialized job.