> Flowering plants is way smaller domain than dicos plants It's the other way round. Dicots are a sub-domain of angiosperms (flowering plants). There are lots

> Flowering plants is way smaller domain than dicos plants It's the other way round. Dicots are a sub-domain of angiosperms (flowering plants). There are lots and lots of flowering plants. All (bar a rounding error) make seeds. Some of the seeds have 1 seed leaf (cotyledon), so are called monocotyledonous plants: monocots. The others have 2 cotyledons: dicotyledonous plants, or dicots. Some monocots use insect pollination and some make edible fruit. Bananas and coconuts are monocots. All cereals (except some false cereals like buckwheat) are monocots, but all are wind-pollinated. Hand-wavey generalisation: most monocots are wind-pollinated, and don't need insects. Many dicots use wind pollination, but most of the ones that make fruit we can eat are insect-pollinated. Some plants are self-fertile and don't need to be pollinated at all (e.g. dandelions). Some can be bred to be that way. If insects disappear it doesn't mean all fruit will. But OTOH it's not just about pollination. Insects do much more than that. They are also vital in decay, in the soil, in turning dead plants back into soil. No insects means much slower decay, means soil that's much less fertile, means plants grow much more poorly, means more crop failures.