The Fruits of Civilization (79) Pollinator Downfall

Pollinator Downfall

The whole fabric of our planet is built on plants and insects, and the relationship between the two. ~ American ecologist Scott Black

Birds, bees, butterflies, beetles, bats, and wasps all have 2 things in common: they pollinate plants, and their numbers are dwindling fast.

Pollinators play a key role in the agricultural system, which also employs millions of humans to feed their world. 35% of the crops grown worldwide, with an annual value of $577 billion, depend upon pollination.

Flying insects have really important ecological functions, for which their numbers matter a lot. Flies, moths, and butterflies are as important as bees for many flowering plants. Flying insects provide food for many animals. Flies, beetles, and wasps are also predators and decomposers, controlling pests and generally cleaning up the place. ~ English zoologist Lynn Dicks

The abundance of flying insects in German Nature preserves plunged by 76% in the quarter century 1989–2016. That finding is likely to be typical of the worldwide trend.

This decline happened in Nature reserves, which are meant to preserve biodiversity and ecosystem functioning. ~ Dutch ecologist Caspar Hallmann

Insects make up about 2/3rds of all life on Earth, but there has been some kind of horrific decline. We appear to be making vast tracts of land inhospitable to most forms of life and are currently on course for ecological Armageddon. If we lose the insects, then everything is going to collapse. ~ Dave Goulson

Many pollinators face impending extinction, including at least 9% of bees and butterflies, and 16% of nectar-loving vertebrates like birds and bats.

In the US, beekeepers lost 41% of their honeybee colonies in 2018. This continued a 21st-century trend of accelerating debility in commercial colonies.

The causes of the decline are entirely man-made. Farming, roads, and buildings eliminate wildflowers and other plants pollinators depend upon. Decades of pesticides have decimated insect populations, and weakened those left alive, leaving them easy prey to parasites and pathogens. Honey all around the world is contaminated with pesticides known to harm honeybees.

Even managing pollinators takes a toll. Trucking honeybee hives around, as done extensively in the US, is disorienting to the captives. Their health suffers, and so contributes to pollinator decline.

If you look at what’s driving honeybee declines, industrial agriculture certainly plays a major role. ~ American geoscientist Kelly Watson

◊ ◊ ◊

Theoretical computer modeling suggests that plants can tolerate losing most pollinator species as long as other pollinators take up the slack. Instead, the plant-pollinator relationship is not so casual. Sustaining relations during a flowering season are important to plant fecundity. In a study of Rocky Mountain larkspur wildflowers, removing a single bumblebee population from pollinating services had profound consequences.

These wildflowers produce 1/3rd fewer seeds in the absence of just 1 bumblebee species. ~ American ecologist Berry Brosi

While particular flower populations are in bloom, certain insect pollinators favor them with fidelity, thus maximizing cross-pollination among the plants.

Most pollinators visit several plant species over their lifetime, but often they display floral fidelity over shorter time periods. They’ll tend to focus on one plant while it’s in bloom, then a few weeks later move on to the next species in bloom. You might think of them as serial monogamists. ~ Berry Brosi

When bees are promiscuous, visiting plants of more than one species during a single foraging session, they are much less effective as pollinators. ~ American biologist Heather Briggs

◊ ◊ ◊

A 2016 survey revealed that US crop production is in dire threat from pollinator downfall. The foolishness of assuming it was safe to spray pesticides at industrial scales across entire landscapes is a harbinger of doom.