The Buzz on Pollinators

We all know pollinators are very important for the production of our food. Bees pollinate the cherry trees, and then the trees produce cherries. Same with apples, oranges, bananas and so on. But did you know that almost all flowering plants need pollinators to reproduce?

The imported European Honey Bee (Apis melifera) is a hard-working and portable source of pollinators that farmers can manage in their fields and orchards to ensure a successful crop. Many of our native wildflowers and trees depend on pollinators too. But what did those plants do before the honey bee was introduced?

It turns out that Florida is home to a host of native pollinators; from native bees to beetles to flies and even slugs! Most flowering plants present their pollen-bearing structures (anthers) sticking out of the open flower to dust pollinators who visit the flower for a nectar reward. As the visitor flies from one plant to another of the same species, the pollen is transferred, and then the pollen fertilizes an egg cell in the flower and a seed develops. There it is, folks, birds and bees…

Generalists

Most flowering plants do not have specific pollinators; any visitor for nectar can be dusted with pollen. Insects use a “search image” that they store in their brain to find flowers of the same or similar species. Like we use the logo of a favorite restaurant, we know from experience that we will get a good meal if we visit the same restaurant in another town. This benefits both the pollinator and the plant.

Specialists

Some plants have particular pollinators. The pollinator is born with the search image already in its brain. It only searches out one species. This guarantees a meal for the insect and the plant’s pollen will only be transferred to a member of its own species. This can be troublesome should anything happen to either partner. In the short term, a late freeze or frost could kill the flower buds of a specific host which might collapse the insect population from lack of food. In the long run, habitat destruction and climate change could separate the partners, eventually dooming both.

Native Pollinators
Halictid Bees

Native bees make up the bulk of Florida pollinators. Halictid bees are small and often very colorful. These are sometimes called sweat bees, because further north, members of this family will land on mammals and drink sweat. Here in Florida look for the beautiful metallic green halictid bee.

A halictid bee (Augochlora pura). Photo Credit: UF/IFAS Lyle Buss

Bumble Bees and Carpenter Bees

Large, fuzzy bumble bees and carpenter bees serve as important pollinators too. Their fuzz collects and transfers pollen very effectively. Bumble bees are very important to plants that have special anthers that only release pollen when properly “shaken.” The vibration of the bumble bees’ wings stimulates the plant to release pollen. This is called “buzz pollination”. Blueberries, tomatoes, eggplant, and kiwi are examples of fruit that are buzz pollinated.

A bumble bee (Bombus spp.) on a thistle plant. Photo Credit: Lara Milligan.

Other Native Pollinators

Other Florida pollinators include male mosquitoes, male horseflies moths and wasps. What about butterflies? They are always flitting from flower to flower! Well, it turns out that butterflies are extremely ineffective pollinators. They are just getting a free lunch from the nectar-bearing plants without returning the favor!

Pollination without Pollinators?

Grasses (including corn and wheat), oaks, pines, elms and ragweed are examples of flowering plants that do not produce nectar and showy flowers to attract a pollinator. These are all wind-pollinated plants. People who suffer from hay fever know how irritating this air-born pollen can be. Goldenrod (Solidago spp.) is often blamed for hay fever, but this is actually an insect-pollinated plant, complete with nectar and sticky pollen. In some climates it flowers at the same time as the easily-overlooked and not showy ragweed (Ambrosia spp.) that is really the one causing itchy eyes.

Blog written by Extension Specialist, James Stevenson and edited by Natural Resources Agent, Lara Milligan.