All Bees are Pollinators, but Not All Pollinators are Bees

May 24, 2023

By Beth Rigby

When the word pollinator comes to mind, bee immediately follows. It is a well-known fact that bees are the exceptional honey producers and pollinators; honeybees alone contribute 14 billion dollars to the US economy each year. However, bees cannot pollinate all of the world’s flora on their own. A plethora of plants and crops attract, or even require, non-bee pollinators. Organisms such as butterflies, moths, beetles, flies, birds, and bats contribute to the pollination of various flora in unique ways.

 

Beetle pollinating a Trillium grandiflorum

Evodinus monticola pollinating a Trillium grandiflorum. Photo by Peter Prehn.

Beetles belong to the largest order in the animal kingdom: Coleoptera. They are the most diverse group of organisms in the world, specifically in terms of their color, shape, and ecological role. In fact, 40% of the world’s known insects are classified as beetles. These insects are attracted to heavily fragranced flowers, as they rely on their sense of smell to find their flowers. Blossoms that release spicy, sweet, musky, or even fermented odors will attract beetles. They will often visit flowers with large cup-like shapes that are open during the day. Since beetles ingest pollen as a primary food source, the plant must be able to produce a surplus of pollen to satisfy both their need to reproduce, and the appetite of the beetle. Plants that are pollinated by beetles tend to do well if they have thicker, tougher, or leathery leaves and petals; beetles often eat their way through leaves and petals, so the plants must accommodate for that. Magnolias, water lilies (Nymphaeaceae), goldenrod (Solidago), sunflowers (Helianthus), and spicebush (Lindera) are all pollinated by beetles.

Hummingbird Moth

Hummingbird Moth by
Dwight Sipler

Two major pollinating insects fall under the order Lepidoptera: butterflies and moths. Butterflies tend towards brightly colored flowers that cluster and provide large landing platforms. Bright colors are more important than fragrant flowers because butterflies have a poor sense of smell. Inversely, moths are attracted to heavily fragranced flowers with dull colors, including morning glory, tobacco, yucca, and gardenia. Ample nectar production is a must for both moths and butterflies, as they subsist off nectar. There are many different species of moths and butterflies that pollinate, but one of the most interesting is the Hummingbird moth. The Hummingbird moth is a unique creature, as it accesses long necked flowers with a long curling tongue.

Flies pollinate many important crops, including cacao, apples, peppers, mangoes, and cashews. Flowers or plants with putrid odors of sap, rotting meat, dung, blood, and carrion often attract flies. Red Trillium is a prime example of this, as it reeks of rotting flesh. Some species of flies become suitable pollinators for niche plants simply because of their size. Chocolate midges, for example, can fit within the intricate flowers of the cacao plant, which are inaccessible to larger pollinators.

Several mammals are known to pollinate, including the ruffled lemur, honey possum, the Noronha skink, and several species of bats. The majority of bats subsist off of insects, but many species enjoy nectar, pollen, and fruit. Scientists are aware of 67 plant families and over 500 species of flowers that rely on bats for pollination. Examples include mangos, bananas, durian, guava, and agave. Bats often pollinate pale colored flowers with very fragrant blossoms- which correlates to their poor eyesight and strong sense of smell. Flowers with a sulfuric or musty odor are also preferred. As they are nocturnal, bats will often pollinate flowers open at night. The long-nosed bat and the long-tongued bat are two examples of common pollinating bats. Much less common is Anoura fistulata in South America. This rare bat uses its extremely long tongue to collect nectar.

 

ruby-throated hummingbird

Male ruby-throated hummingbird by
Tibor Nagy

There are roughly 2,000 species of pollinating birds on Earth, including hummingbirds, honeycreepers, honeyeaters, sunbirds, and even some parrots. The flowers must be prolific nectar producers, as birds often subsist off of the nectar. As the bird forages for nectar, the flowers will dust the birds head and back with pollen. They prefer flowers with a tubes, funnels, and cup, as this shape is easily accessed by a bird’s beak. A strong support for birds to perch on is a plus. Birds have a poor sense of smell, so odorless flowers will not deter them. However, blossoms with bright red, yellow, and orange petals will attract their attention. Hummingbirds in particular have incredible eyesight and are attracted to red. They must eat several times their weight in nectar daily for subsidence. Generations of adaptations perfected their long and slender bill to be perfect for nectar collecting. For protein, they will also ingest small bugs. In the Eastern United States, it is possible to spot a Ruby-throated hummingbird.

If interested in attracting a diverse range of pollinating species in a garden, be sure to plant a variety of flowers with overlapping bloom times. The flowers should range in shape, size, and color. Avoid insecticides and herbicides. Protect soil health with mulch and compost to protect organisms in the soil, including beetle eggs and larvae.

 

Sources

Who are the Pollinators? (WP)

That’s not a bee! (NAB)

Bees aren’t the only pollinators you can attract (B)

Notes from Other Orders: Beetles as Pollinators (NOO)

US Forest Service: ________ Pollination 

Bat Conservation International