From our August Home and Garden publication: Columbia Gorge Beekeepers: Megachilinae / Leafcutter

Summer is in full swing! Hopefully you have ventured outside exploring the flora that brings beauty to the Columbia Gorge area. Have you seen any native bees visiting their grocery store — the flowers and plants? Native bees are out foraging for nectar and pollen to support their brood (babies). Each egg must have a bit of nectar and a splash of pollen.

Honey bees, on the other hand, forage not only for their brood but sustenance for the long winter months ahead. The native bee’s queen hibernates through the wintry season, only surviving one year. Thus, the need for nectar stores is unnecessary.

There exists a symbiotic relationship between pollinators and the flora surrounding their habitat. The plants and flowers rely on pollinators to move pollen from the flower’s anther (male part) to another’s stigma (female part). Of course, from the bees’ part, the need for nourishment supplied by the plant or flower is greatly needed to support the superorganism of the honey bee colony.

Bees, whether native or the European honey bee, thrive on nectar (which dehumidifies into honey) and pollen. Pollen contains proteins, amino acids, carbohydrates, lipids and fatty acids, phenolic compounds, enzymes, and coenzymes as well as vitamins and bioelements. The ingredients support cell division, repair and growth. Nectar is essentially sucrose, or sugar, providing energy to the bees.

Native bees come in two varieties: Generalists and specialist. The generalist searches for a multitude of flora while the specialist seeks out specific flowers. An example in Oregon is the Squash Bee.

The native bees are so-called as they emanated from North America while the honey bee is worldwide. The honey bee populating the United States is considered the European as it exists in that region of the world. Each sub species displays differing behaviors, takes up housing in a different way, and pollinates the natural flora of that region.

The Megachilinae, leafcutting bee, is a small compact black bee typically seen in late spring and summer. Their motion is energetic, swimming-like motion releases the flowers pollen. The concealed stamens and pistils in alfalfa flowers can be triggered to release by the leafcutter.

Like other bees, they emerge in the spring. Mating occurs shortly after. The male ceases to thrive once mating is complete. The leafcutter does not reside in colonies as honey bees do but rather form a solitary life style. Each queen — mother — assumes the care of her own young.

They nest in a variety of cavities such as wood or hollow stems. A few seek underground abodes. The pencil size nest is all they need. It is here the family begins.

The mother exits her home in the spring to gather nectar in her crop (stomach) along with pollen which is kneaded into a bee loaf while adding some of her own saliva for moisture. Her saliva contains antibacterial and fungicidal qualities. Several trips gathering nectar and pollen are necessary to accumulate sufficient quantities large enough to feed one grub (larvae) which hatches from the mother’s egg.

Mom seals the brood chamber with chewed up leaves. Small, nearly perfect round holes in leaves may be sighted in your garden indicating a Megachilinae is close at hand. The mother continues to build segments until she creates the final closure consisting of a thicker wall. Consider the nest similar to a pipe with segments housing each egg separated by the leaf wall. Once complete, she dies shortly afterwards.

The babies feed on the pollen and nectar bee loaf until they grow into an adult remaining dormant until the next spring.

The emerging adult chews its way out, mates and is ready to engage in the circle of life all over again.

The honey bee thrives in a colony, which expands each year to accumulate on average 100 pounds of nectar to support their winter life. The beauty, at least for us humans, is the hive stores more than sufficient quantities, thus affording us an opportunity to steal some of the sweetness they have labored to forage and dehydrate into honey.

But the importance of all the pollinators comes down to the plants and flowers requiring the transfer of their pollen from anther (male part) to another’s stigma (female part). What would the Columbia Gorge look like in the absence of these vital pollinators.

Discussion abounds concerning native and honey bees. Is one deleterious to the other? All it takes is an exploration to witness the bumble bees and honey bees foraging on the same flowers. Native and honey bees often select different floral species. Thus, if there exists competition, it is minimal.

Access to clean, nutritious forage is essential for all bees, and as bee forage is declining each year in the United States, the number of native bees and managed bees are also declining. Seventy-five years ago there, were nearly twice as many honey bee colonies in the U.S., and more than half the native bee species assessed seem to be in decline.