In Poland alone, there are 470 species of wild bees, and around 20,000 species worldwide (that we know of). However, bees are not the only pollinators, as beetles (which pollinate species from the water lily family, such as water lilies), butterflies, and hoverflies also take part in pollination. What’s more, there are also animals that pollinate, including birds (such as hummingbirds or honeyeaters, which pollinate Australian mistletoes) and even mammals, such as bats, which pollinate agaves, without which we wouldn’t have tequila or syrups.
Let’s focus on other types of bees, as the honeybee often takes all the glory. While the honeybee is an excellent pollinator of crops and responsible for producing 80% of food that requires insect pollination, it has been observed on only 10% of insect-pollinated plants in wild environments (where there were no hives nearby).
Bumblebees
We have several species of bumblebees in Poland. All of them belong to the bee family. However, we usually see the common bumblebee in gardens. They are commercially bred and used in greenhouses to pollinate tomato crops. The honeybee would not be suitable for this, as it is more aggressive (and there are people working in greenhouses) and cannot perform vibrational pollination, which is necessary to obtain high yields from these crops.
Vibrational pollination involves making the thoracic and wing muscles vibrate intensely. This is useful for plants with atypical anther structures, where the anthers are fused into a tube with an opening at the tip, and the pollen grains are enclosed inside, so they need to be shaken out. This pollination strategy is adopted by around 8% of insect-pollinated plant species, narrowing the group of insects that can transfer their pollen. Some cultivated plants from the nightshade family, such as potatoes, eggplants, tomatoes, and peppers, have “difficult” anthers. Bumblebees can shake the pollen out of the “anther tube” by intensely vibrating their abdomen. Without this behavior, the yield of the plants would be much lower.
That’s why, when observing honeybees and bumblebees feeding on flowers, we can notice that the former feed in silence, while the latter produce a loud buzzing sound.
Lucerne Bee (Megachile rotundata)
This species is native to Europe, and although it visits many flowers, it prefers those from the legume family, such as alfalfa, from which it gets its name. These flowers have a specific structure, consisting of a boat-shaped petal and a “sail” petal. The flower’s keel hides long stamens inside. When the pollinator lands on it, it automatically weighs it down and bends it, releasing the flexible stamens that strike the pollen sacs against the “sail” petal, releasing the pollen.
The movement of the anthers upwards is so dynamic that they “whip” the bee with considerable force, which causes the honeybee to become disoriented after visiting an alfalfa flower and take some time to recover. In contrast, the lucerne bee is resistant to these “stings,” making it an effective pollinator.
Alfalfa is an important fodder plant (used for feeding livestock), and since honeybees are not particularly good at pollinating it, the lucerne bee has been introduced to other continents to handle its explosive flowers and ensure high yields.
An interesting behavior of the lucerne bee is lining the inside of the cells where it lays its eggs and pollen with pieces of leaves. It cuts them with its mandibles, as shown in the photo.
Garden Mason Bee
Fruit growers have fallen in love with this species of bee. It has one generation per year, appearing from April to June – the blooming period of most fruiting plants, such as apple trees. Mason bees are solitary. They lay eggs with pollen balls in empty stems (e.g., reeds), cracks in tree bark, and corridors drilled by beetles, and they also nest in wall crevices – hence the first part of its Polish name. Bees separate each chamber where a new female or male will develop with a clay wall. In spring, new bees emerge from the cells and establish their own nests.
Mason bees can be invited into gardens by building reed houses. They are gentle bees, and due to their ease of breeding and excellent timing, they are used by orchardists because they don’t need to be cared for – all that’s needed is to place mason bee cocoons in the orchard, and the bees can be left to do their work. Meanwhile, honeybee colonies, although they are large in number, require more care.
Author’s note: Martyna Walerowicz
Main fot.: Kornelia Młynarczyk