May 13, 2021

Team of pollinators means better yield for crops

SPRINGFIELD, Ill. — When it comes to pollinators, teamwork makes the dream — of more lush and bountiful specialty crops — work.

“While most of the time it’s going to be bees pollinating our plants, there are a variety of insects that may visit our plants and pollinate them. Don’t discount some of these other insects when it comes to pollination,” said Ken Johnson, horticulture educator at the University of Illinois Extension.

Johnson discussed the array of pollinators for specialty crops, including fruit and vegetables, at the 2021 Illinois Specialty Crops Conference.

The benefits of pollination are obvious: fertilized flowers produce a fruit or vegetable. But a lack of adequate pollination can show up, as well.

“If you have misshapen fruit, a lot of times that’s because of poor pollination. Either pollinators weren’t present or you had bad weather and pollinators weren’t flying,” Johnson said.

Some of the benefits of adequate pollination go beyond the row. Johnson cited research that has been done to discover how the type of pollination, by insect, wind or self pollination, impacted yield and other characteristics of strawberries.

The research found that insect-pollinated fruit crops were 11% heavier than wind-pollinated fruit and 30% heavier than self-pollinated fruit. The insect-pollinated fruit also had deeper color and had a longer storage life, with 40% of the fruit from insect-pollinated flowers being marketable after four days, compared to 29% of the fruit from wind-pollinated flowers and none of the fruit from self-pollinated flowers.

Creating A Buzz

Many fruit and vegetable crops, including melons, cucumbers, squash, pumpkins, tree fruits like peaches and apples, and berry crops, including raspberries, blackberries, blueberries and strawberries, need to have pollination in order to produce a crop. Other crops don’t need to have pollinators, but tend to yield better if they have pollinators. Those include tomatoes, peppers, eggplant, lima beans and okra.

One benefit of having a diversity of pollinators is that each group may prefer to forage for pollen in a different part of the flower, resulting in a flower that is more thoroughly pollinated.

“There have been studies done where honeybees prefer the center of the strawberry flower and some of the native bee species tend to pollinate the perimeter, so you get the entire flower being pollinated that way, both the inside and the outside. That better pollination leads to bigger berries and better colored berries,” Johnson said.

In addition, different species, especially of bees, can make boost pollination efficiency. Different species of bees work together to pollinate plants, but other pollinators include lady beetles, butterflies, moths and some fly species can help pollinate plants.

“Honeybees may not be the fastest pollinators and some of our native species are a little bit faster at pollinating,” Johnson said.

Bee A Friend

Honeybees, which are the most well-known of the bee species, are the most important bee for pollination for a variety of crops. But other bee species play important roles when it comes to pollination of a wide variety of flowers.

Bumblebees: These bees are the next most important to honeybees. Bumblebees are short-lived. Their colonies only last for a growing season. They are medium-sized and a bit bigger than honeybees, but similar in color. They nest in the ground. Bumblebees do a form of pollination called buzz pollination or sonication. They hold onto a flower, buzz and vibrate the flower, which causes the release of pollen. Bumblebees also operate in cooler temperatures than honeybees. They may be out in temperatures lower than 50 degrees or in rain or drizzle.

Carpenter bees: Carpenter bees are larger and usually solitary. They bore holes into wood to create nests.

Small carpenter bees: Smaller than their larger counterparts, they build nests in softer wood, like dead berry canes or dead wood.

Mason bees: Mason bees are tunnel nesters, choosing to build their nests in woody stems, beetle galleries or homemade nesting boxes. They collect pollen on their abdomens and are active in the early spring, so they are an important pollinator for early season flowering fruit trees.

Leafcutter bees: They are known for cutting circular pieces out of the leaves of plants like roses or ash trees to line the walls of their brood cells. They emerge in the summer and are useful for pollinating plants that bloom in the summer.

Sweat bees: They nest in the ground and are solitary. They are attracted to the salt in sweat. They prefer smaller flowers, like those of herbs, and are out in the summer and late summer.

Squash bees: Squash bees are vital for pollinating squash, pumpkins and gourds. They can be found nesting near these plants in ground nests. They tend to be active from dawn through the middle of the day, while squash blossoms are open.

Jeannine Otto

Field Editor