A sweet slice of watermelon. A juicy tree-ripened peach. A cold crisp apple. A slice of warm pumpkin pie.
All of these foods I look forward to each summer and fall, and I can pretty much count on those foods being available at Kroger or Walmart or Rhoads. However, a lot of things need to happen first.
Seeds must be planted and plants need to spring forth from those seeds. The plants then have to set flowers, which then need pollinated so that the fruits and vegetables can grow from them. They have to be picked and brought to market.
Each one of these steps is important but I’d like to focus on the flowers needing pollinated.
Pollination, as defined by the U.S. Forest Service, is “the act of transferring pollen grains from the male anther of a flower to the female stigma.” Plants have evolved two different methods of pollination, abiotic and biotic. Abiotic pollination occurs without assistance from another organism. About 20% of pollination is abiotic. The remaining 80%, biotic pollination, is mediated by animals including birds, bees, wasps, butterflies, moths, beetles, flies, ants, bats and other animals.
Abiotic pollination occurs by either wind or water with 98% by wind and 2% by water. Wind pollination brings us that sweet corn on the cob as well as oats, wheat, rice, rye, barley and other grasses. Trees including walnut, pecan and pistachio are wind pollinated. Plants that use wind pollination for reproduction produce flowers that are small, lacking color, fragrance or nectar. Most have no petals. They produce copious amounts of light, smooth pollen that will lift easily on the wind.
So that leaves us with our sweet watermelon, juicy peach, crisp apple, and pumpkin pie. All these favorites of mine reach our table thanks in part to biotic pollination, pollination by animals. Of those animals, the largest majority by far are insects: bees, wasps, butterflies, moths, wasps, ants, beetles. Here’s how it works:
The insect needs the nectar for energy and the pollen for protein. The plant needs the pollen transferred from the male anther to the female stigma so that fertilization can occur. So, for the plant, it’s all about attracting pollinators. For the insects and other animals, it’s all about getting that pollen and nectar for nourishment.
Plants and pollinators have co-evolved in order to foster pollination. Plants have developed flowers with visual cues such as showy petals, bright colors, nectar guides (color patterns within the flower that guide the insect to the pollen and nectar), unique shapes that have evolved to attract a certain pollinator, and large size. Some plants have flowers with scents while others provide food in the form of nectar and pollen formulated to attract certain pollinators. For example, plants that depend on hummingbirds and other high-energy animals for pollination produce large amounts of nectar (sugar water) with a higher concentration of sugar. Other strategies plants use to attract pollinators include mimicry and even, entrapment.
For their part, animals have evolved physical characteristics that aid them in the collection of nectar and pollen. Honeybees and bumblebees have “pollen baskets” on each hind leg to collect balls of pollen and nectar. Hummingbirds with their long thin beaks and tongues and butterflies and moths with their straw-like proboscis can easily drink the nectar from tubular-shaped flowers.
As you can see, the plants depend on the animals just as the animals depend on the plants. Each, over time, have developed these strategies in order to survive. And we, incidentally, can enjoy that watermelon, peach, pumpkin pie, cherry cobbler, sliced tomato and crisp apple. In fact, according to the U.S. Forest Service, “Of the 1,400 crop plants grown around the world, almost 80% require pollination by animals.”
Put another way, pollinators are responsible for one out of every three bites of food you eat. Yet populations of insects are in decline and have been since the beginning of the 20th century. Suspected causes for this decline include use of pesticides, diseases, habitat destruction, climate change, air pollution, effects of monoculture, and competition between native and non-native species.
How can you help? If you’d like to learn how, join the Friends of Circleville Parks at our program, Planting for Pollinators: How to Plan and Plant a Pollinator Garden on Saturday, July 13th at 11 a.m. at Shelter House #2, Mary Virginia Crites Hannan Park, 1230 Pontius Rd., Circleville, OH. Our presenter, Christina Bobek is a local beekeeper and Master Gardener Volunteer. Children under 12 are welcome but must be accompanied by an adult.
For further information, please contact:Brenda Johnson at firstname.lastname@example.org or 740-497-0119; Melanie Shuter at email@example.com or 740-601-4907; or, Paul Hang at firstname.lastname@example.org or 740-497-4397
Brenda Johnson is an Ohio Certified Volunteer Naturalist