Why should we conserve small insects like a bee or butterfly

Bees and Butterflies both pollinate flowers and plants, without them we would have no trees or food that's grown. Without these we would not only have a good source for our livestock, but our own diets would be put off balance, not to mention we would have little to no oxygen from the lack of photosynthesis. Which would result in the demise of humans and most to all living things.

This is a time line from 685 to 978