I wonder if all these beehives and bee keepers are similar to a bunch of pastoral goats and herders? Almost no control of who puts a beehive somewhere (tragedy of the commons). Those bees then strip all of the surrounding area of flower nectar, leaving nothing for the natural insects, which then die. Bee keepers go all over the US to place their hives and then bring them to California to pollenate the nut trees. Plus the rise in the popularity of honey and the trendiness of having hives for fun.

In addition, bees' diets by commercial beekeepers are often supplemented by man-made sugars. To continue the analogy, imagine that there was someplace that really wanted a bunch of goats for two weeks a year to eat up a bunch of plants as a brush clearing method. People get paid a lot to have goats arrive at that location every year. The laws of the country are such that goats are allowed to roam anywhere and eat plants on people land and fences have not been invented yet. You only have to own the land where they come back to at night(the corral). The goat herders try to maximize the size of the herd by feeding the goats a cheap but nutritiously deficient food for most of their calories, but goats have to get some vital vitamins, proteins, and minerals from the stuff they eat in the wild. In fact, over the centuries the goats have evolved so that they can run fast and long away from the corral in the morning, just to get somewhere that has not already been stripped of wild food that they need, burning the calories supplied by the goat herder. The goat eats for a few hours somewhere that is not already over-grazed, and then runs back to the corral.

When the goat returns it has a way to tell the other goats where it went to find a good place to eat and the next day hundreds of goats head out to that location to strip it to dirt in one day. Other goats head out somewhat randomly on a dead run to try and find somewhere around that has something to eat.

This goat hive can only exist in one place when the grass is sprouting or in places that goats have not been in many years. The goat herders corrals are built on huge trucks so that when they need to move the goats to somewhere else, because the local area is completely stripped, they can just start up the truck and be in a new location 500 miles away in a single day.

A disease now starts spreading among the goats. They get shipped around everywhere so it spreads to other herds really fast. The goats are dying at a high rate and no one knows why or how to cure it, but the goats breed pretty fast. The goat herders can keep the number of goats high enough to meet the demand of the companies that need the annual grazing clearing, but only because of the increasing price the companies are willing to pay. This incentivizes more goat herders breeding more goats at a furious rate. The surviving herders are now searching hard for the last places that have not been completely stripped mined of wild food. Never a blade of grass springs from the Earth where a goat is not immediately there to eat it.

You can imagine what such a system would do to the wild grazing animal population. Anything wild would never find anything to eat, the predator populations would be huge, gorging on the free roaming goats that the herders don't guard. The herders have no way guarding hundreds of thousands of goats. They could not possibly watch over each one and don't even think about how that might be done.

Now add in farmers that grow plants the goats can't eat. They cover huge areas where only a small amount of the wild plants survive that the goats need. Around the farms wild plants still grow, but farms are being consolidated and those edge areas are being eliminated. Some wild animals can eat what the farmers grow, so the farmers develop chemicals that kill the animals that eat their crops. This chemical will also kill goats and gets on the few remaining wild plants the goats eat and poison them too.

Now imagine that the goats and wild animals are so small that the herders and other people in society don't really notice them at all. They only start to worry about the goats when there are not enough goats arriving every year to clear out the brush where the annual spring picnic is held. Only after that happens do a few quirky scientists start looking into the problem and notice that these wild animals that have to compete with goats have been dropping in numbers like crazy for quite awhile.

Just an analogy, but maybe some truth to it?