Imagine a beautiful, orange Monarch butterfly flying around your garden. Do you know why it’s there? Do you know what would happen if it wasn’t there? Probably not. But, this beautiful butterfly can pollinate all of the flowers in your garden and make it possible for more flowers to grow!
Pollination is how we get seeds. Seeds give us many of the flowers, fruits, vegetables and plants we love. The pollination process involves pollen from one type of flower (specifically from the flower’s anther, or male part) being transferred to another flower (specifically to the female stigma). The result is flowers producing seeds!
How do pollinators pollinate?
More than 20,000 wild bee species and countless species of butterflies, flies, wasps, moths, beetles, birds, bats, and many other animals are pollinators who help support the foundation of our food supply.
When a pollinator such as the Monarch butterfly needs a meal, it flies over to the nearest flower to obtain nectar or protein-packed pollen that provides the butterfly with energy. Food (nectar and pollen) is the clear driver for a butterfly to visit a garden or field of flowers. However, many flowers may also use specific scents, colors, and petal shapes to attract pollinators. While the butterfly is eating, pollen grains can attach to the outside of the butterfly and stick to its body. When the butterfly flies away from the flower, it carries this pollen on itself and when it lands on another flower (of the same species) it is able to fertilize it via a pollen transfer. This type of pollination is called cross-pollination.
So, fundamentally, when a pollinator takes pollen from the male anther of a flower to another flower, there is a chance that this pollen will fall off into the new flower’s stigma, which may result in the maturation (germination) of the pollen. Germination occurs when the grains of pollen are able to begin forming into seeds.
Self-pollination is a bit different than cross-pollination. Self-pollination occurs when the pollen of a flower makes its way to the stigma of the same flower. The new plant will be the same genetically as the old plant. Because of this, self-pollination can reduce genetic diversity.
How do pollinators help the food supply?
Pollinated crops include vegetables, fruits, seeds, nuts, and oils. More than 75 percent of the world’s food crops depend on pollination in one way or another.
When a seed forms in flowering plants, a fruit is able to grow to protect the seed. These fruit-bearing plants act as an incentive to animals that eat the fruit and excrete the seeds for growth in another location. The whole cycle is interconnected. Without pollinators, it could be impossible for a flowering plant to produce fruit. The flowers of vegetables also produce seeds that allow more vegetables to be grown.
The reproduction of plants from pollination dramatically increases the yield of crops that could otherwise not be able to reproduce. If pollinator populations decline, it could have a negative impact on crop and flower pollination, and ultimately, the diversity of our food supply chain. Therefore, ensuring the proliferation of pollinator species is crucial to the world’s food supply that is currently feeding 7.4 billion people.
How does this increase our access to nutritional foods?
Without access to foods that are a direct result of pollination, consumers would have limited access to essential nutrients, vitamins, and minerals. The results of this could be a decrease in access to many different foods that the population relies upon on a daily basis. An increase in malnutrition and related negative health outcomes are possible as well. Malnutrition can lead to weight loss, limited mobility, and stunted growth if experienced for extended periods of time.
The buzz about pollinators and pesticides
The proliferation of pollinator species is essential to the survival of our world food supply. One concern is that there are some pest control methods that have potential to negatively impact pollinators. Pesticides are designed to protect our fruits and vegetables by keeping harmful insects away, while also minimally impacting the ecosystem.
Recently, a 2018 study used a small sample bees to test the effects of glyphosate on bee gut microbiomes. While the study detailed changes in the bee microbiome due to glyphosate exposure, the body of scientific evidence indicates that there is no link between glyphosate exposure and honey bee health.
However, residues from one class of pesticides, called neonicotinoids (neonics), have been evaluated as potentially causing the decline of bee populations. A study released in 2017indicated that neonicotinoid-treated seeds of canola oil plants had negative effects on the reproductive potential of bees. This led to smaller colony sizes in subsequent seasons, but results varied greatly between countries where the study took place. They found some negative effects after exposure to neonicotinoids in wild and honeybee populations, and also some positives, depending on other relevant environmental factors. In addition to this, the European Food Safety Commission’s (EFSA) recently reviewed neonicotinoid impact on bee populations. EFSA released a 2018 report indicating that “most uses of neonicotinoid pesticides represent a risk to wild bees and honeybees.” The Authority updated its risk assessments of three neonicotinoids – clothianidin, imidacloprid and thiamethoxam – that are currently subject to restrictions in the EU “because of the threat they pose to bees.”
However, on the other end of the neonic study spectrum, research has also found that there are agricultural benefits to using neonicotinoids and that honeybee populations are on the rise. A 2015 study discovered that using these pesticide seed treatments decreased the use of other spray pesticides and in turn were beneficial to farmers. Further, the U.S. Department of Agriculture (USDA) released a honeybee health survey in summer 2017 that showed, U.S. honeybee colonies rose three percent to 2.89 million as of April 1, 2017 compared with a year earlier. USDA goes on to note that, beekeepers who owned at least five colonies, or hives, reported most of the losses from the varroa mite. These mites thrive on sucking blood from adult bees and their progeny.
So where does this leave us? Going forward, farmers will continue to responsibly utilize pesticide management programs to ensure strategic use that keeps crop productivity balanced and pollinator species safe.
Our Pals the Pollinators
Who knew something as small as a bee or a butterfly could be so important to keep us healthy? By simply seeking out food for themselves, pollinator species are able to increase crop yields for many different foods and they help ensure that our food supply remains diverse and plentiful.
This blog post was written by Danielle Corrado, food science/policy intern from the University of Massachusetts, Amherst.