Inviting Pollinators with Plants

Understanding pollinators

Understanding pollinators (2)

HONEYBEES

Honeybees are native to just about everywhere. They vary from gold to brown to black. Most importantly, though, they all are fuzzy, which is ideal for collecting loads of pollen that they store in their pollen basket, a specialized body part called a corbicula, as they buzz back to the hive. Honeybees are generalist foragers, meaning they visit a variety of flowers. The location and quality of flowers they find is communicated to other workers through pheromones and an intricate “waggle dance.” They are not adapted to every plant they encounter because they are a foreign species, though, and sometimes practice nectar robbing. This involves tearing a slit in the side of a flower to extract the nectar without having to enter the bloom or pollinate the flower.

NATIVE BEES

They are generalists and forage on a wide variety of flowers. Bumblebees are able to shake pollen from a number of flowers that honeybees can’t access. Using “buzz pollination,” they grab the flower and vibrate their wings at a high frequency until the pollen falls from the blossom. They are important pollinators of tomatoes, watermelons, and blueberries, among other food crops.

OTHER POLLINATING INSECTS

Butterflies

Butterflies are measurably less efficient than bees at the business of pollination. Yet they may be the most popular pollinators because of their gorgeous colors and captivating flight. Their tall, slender bodies aren’t conducive to picking up much pollen. With their long proboscis, however, they can reach into flowers many bees can’t access. And unlike bees they are able to see the color red. For this reason they are often seen at brightly colored red, purple, and pink flowers that bees may pass by. They are important pollinators of wild and cultivated flowers, especially aster, goldenrod, dogbane, zinnias, and dahlias.

Moths

Moths work the night shift, searching out flowers that open in the late afternoon to evening especially for them. Many of these drab creatures are attracted to similarly dull-colored blooms in white, pale purple, and pinks that reflect moonlight. They are lured in further by the heavy fragrance that promises copious amounts of nectar. Of the moths that show their faces in daytime, large hovering hawk moths are well known as doppelgangers for hummingbirds. Many of these winged, nocturnal creatures are responsible for pollinating appealing plants, such as night-blooming jasmine, gardenia, yucca, and brugmansia.

Flies

Despite their negative connotation, many members of the order Diptera are economically important pollinators of annual and bulbous ornamental flowers. Look closely and you’ll see that hoverflies act like tiny helicopters, visiting flowers with a dart-and-hover technique quite different from the more methodical bees. You’ll see them nectaring shoulder to shoulder with other various bee species as well.

Wasps

With such shiny bodies, wasps aren’t usually thought of as good pollinators. While nowhere near as efficient as most bees, they do visit flowers and leave with a fine coating of pollen dust. The fig wasp is notable for its self-sacrificing pollination service. The tiny wasp squeezes into the immature fig fruit that keeps its flower structures hidden inside. The wasp visits the internal flowers and lays her eggs in the future seeds, spreading pollen from the fig from which it originally emerged. She never sees the light of day again.

Beetles

Beetles, by their sheer numbers, are actually the largest set of pollinating animals in the world.

Two-thirds of the entire world’s plant species depend upon animal pollination. It could be said that insects run the world. Yet many people still don’t realize the critical role pollination plays in maintaining human sustenance and a healthy, diverse ecosystem. 

Pollination is the transfer of pollen grains from the anther of one flower to the stigma of the same or another flower. This helps the plant to successfully reproduce. Some plants are wind-pollinated; a few are even pollinated by water, but most depend on insects, birds, and a few other animals. Bees collect different shades of pollen depending upon the flower source. Plants that use the wind to reproduce throw out huge quantities of lightweight pollen grains (the ones most responsible for all of those miserable symptoms) that fly through the breeze. Many trees, such as willow, birch, walnut, conifers, and even grasses rely on this system, one that takes advantage of an abundant natural resource without expending energy on producing conspicuous flowers to entice insects. Their flowers don’t produce nectar and have little to no fragrance. Their stamens, like those on birch catkins, are exposed to make it easier to catch pollen passing by. With this scattered shotgun approach, though, enormous amounts of pollen miss their mark and are wasted in the process.
Image Pollen sticks to this long-horned bee’s hairy body. It’s then transferred as the bee moves from flower to flower.

Insect pollination, on the other hand, is highly efficient and accurate. Pollen grains are held on the anthers at the center of the flower. When bees, butterflies, and other pollinators visit the flowers looking for nectar, they brush against the flower’s anthers, catching the pollen grains on their bodies. Bees also seek their share of the pollen, packing it into specialized structures on their hairy bodies to transport back to their hive. As pollinators move from flower to flower, some of the pollen falls off and sticks to the stigma, the prominent female flower part that serves as the entrance to the flower’s ovaries. The pollen grain is made up of two cells: one forms a pollen tube which then directs the other generative cell taking the pollen down into the depths of the flower where it fertilizes the waiting egg. Once fertilized, this enables the plant to make seeds.