Insect pollination is essential for healthy crop development. In fact, most of our favorite foods, from oranges and kiwi to avocados and onions, rely on pollinating insects to produce seeds and grow into food.
Of the top 100 crops that provide 90 percent of the world’s food supply, almost three-fourths rely on pollination by bees. The rest need flies, beetles, Lepidoptera (butterflies and moths), birds and bats to act as pollinators.
While concern over the decline of domesticated honeybees has grown in recent time, new research shows that wild bees and other insects may be just as important to the success of the agriculture industry.
In a study of 600 fields of 41 major crops (fruits, grains and nuts) on six continents, researchers found that wild insects pollinate these crops more effectively than domesticated honeybees. In fact, compared to bees living in apiaries, wild pollinators lead to twice as much of what’s called “fruit set”—the amount of flowers that develop into mature fruits or seeds.
Many of our food crops depend on a process known as buzz pollination. Honeybees aren’t capable of this kind of pollination, says Lucas Garibaldi, a professor at the National University of Río Negro in Argentina and lead researcher on the new study. This is why protecting wild pollinators and bees is so important.
It was astonishing. The result was so consistent and clear. We know wild insects are declining so we need to start focusing on them. Without such changes, the ongoing loss is destined to compromise agricultural yields worldwide.”
Numbers Declining Rapidly
According to scientists at the World Wildlife Fund, monarch butterflies have declined more than 59 percent over the past two decades. Because of their long annual migration, monarchs are among the most important of the Lepidoptera pollinators.
The wild bee population, as well as the number of different species of the insects, has also plummeted over the last 20 years. Of 109 bee species documented in the 19th century, only 54 remained by 2010.
Beekeepers have long experienced colony losses from typical sources like bacterial agents, mites, and other parasites and pathogens. These loses are managed by antibiotics, miticides, and integrated pest management techniques.
Unlike these common problems, the recent die-offs have been virtually instantaneous, causing scientists to look for other culprits behind the continuing decline of wild pollinators.
Genetically Engineered Crops, Pesticides Linked to Decline
Until recently, there was no conclusive evidence on the cause of colony collapse disorder. New studies point an accusing finger at a culprit that many have suspected all along: a class of pesticides known as neonicotinoids. In the U.S. alone, these pesticides, which target the nervous systems of insects, coat a massive 142 million acres of corn, wheat, soy and cotton. Neonicotinoids are absorbed by a plant’s vascular system and contaminate the nectar and pollen bees and insects come into contact with.
Genetically engineered crops, also known as genetically modified organisms or GMOs, have also been linked to the rapid decline in wild pollinators. These crops were first approved for agricultural use in 1996, and now make up nearly 70 percent of corn, soy, canola, and cotton production in the United States. Outside of the US and Canada, most countries have either banned the production and import of GMOs or require them to be labeled as a part of basic consumer information.
The most common types of GMOs are those either engineered with genes from a well-known bacterium, bacillus thuringiensis (Bt), to produce their own pesticide, or modified to withstand heavy applications of the herbicide glyphosate (the active ingredient in Roundup). These traits are commonly “stacked” into the same crops.
Bacillus thuringiensis has been used as a spray insecticide by farmers and gardeners for decades to control butterflies that damage cole crops such as cabbage and broccoli. But unlike the Bt spray, which breaks down quickly after application, the toxin in the GM crops is present in each cell (including the pollen) and does not break down in the environment.
Engineered Bt crops also target a larger variety of insects than the insecticide spray, affecting beetles, flies and mosquitoes as well as butterflies and moths. These insects are killed when the Bt toxin ruptures their stomachs. Bees are affected in a different way by the toxin. Rather than killing them directly, it has been found to reduce their learning and foraging abilities, which over time results in colony collapse.
The ability of genetically altered crops to survive large pesticide applications has also allowed for a massive increase in the use of these chemicals. Industrial application of the herbicide Roundup (manufactured by chemical giant Monsanto) has increased by 527 million pounds since 1997. Roundup has been found to directly kill bees. In February, 1,500 colonies of honeybees were destroyed by the fumigation of corn crops in Campeche, Mexico. Overuse of industrial herbicides has also resulted in habitat loss for wild pollinators. Butterfly populations, for example, have been devastated by the loss of milkweed, which also feeds numerous species of beetles and other beneficial insects.
Although the situation looks dire, there are still options available to avoid disaster. Germany and France have already banned the pesticides that have been implicated in the deaths of bees. Hungary, Poland and Peru recently destroyed and then banned all genetically engineered crops from their borders. According to environmentalist and author Bill McKibben, there is still time to save bees and other pollinators by working with nature rather than against it:
Past a certain point, we can’t make nature conform to our industrial model. The collapse of beehives is a warning – and the cleverness of a few beekeepers in figuring out how to work with bees not as masters but as partners offers a clear-eyed kind of hope for many of our ecological dilemmas.”
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