A Garden of Specialists

On a recent August morning, Native Beeology founder, Tim Stanley and the YMCA Kingston Farm Project staff and interns gathered together to explore the urban garden and see what bees were busy at work pollinating the plants in blossom. The mission of the Kingston YMCA is to educate and empower young people and their families in the City of Kingston by directly engaging them in sustainable food production at their urban farm while increasing the community’s access to fresh, local food. The garden is an impressive sight and a testimony of the hard work of the staff and the pollinators that work in partnership to ensure a bountiful harvest.

Taking a closer look at some of the bees in the garden.

Specialists

The first discovery on the morning garden tour were the long horn bees (Melissodes spp.) actively pollinating the sunflower blossoms. The beautiful sunflower looks like a single flower but a closer inspection reveals a collection of many tiny little flowers called disc florets surrounded by “petals” that are really flowers also, called ray florets. Sunflowers are one example of composite flowers that are a member of one of the largest flowering families that include asters, dandelions and echinacea. Long horn bees are a medium sized bee and a specialist of sunflowers. As their name implies the male bees have extra long antennae while the females antennae are much shorter and they have shaggy scopa hair on their hind legs used for collecting pollen. Like most native bees these are solitary bees where every female is an egg layer. Long horn bees represent the 70% of solitary bees that nest in underground chambers. The males feed on nectar during the day and congregate on the edges of the sunflowers to spend the night. Joining the long horn bees are many other species of native bees including smaller sweat bees that can be seen defending their right to share in the rewards offered by the field of disc florets.

A female long horn bee encounters a dark sweat bee on a sunflower. The smaller sweat bee defended her space successfully.

The pumpkins, zucchini and other squashes with large orange blossoms attract an assortment of bees including squashes very own specialist, the squash bee (Peponapis Pruinosa). The squash bee is about the same size and coloration of a honey bee but it a much faster bee. These two natives, the fruit and the bee share a long evolutionary history dating back to the mastodons and each summer the squash bees emergence coincides with the blossoming of the plant. The nectar lures in other bees such as bumble bees, honey bees and sweat bees but the squash bee actually begins pollinating long before the summer sun rises giving them a distinct advantage over other bees. Male squash bees remain inside flowers as they whither in the noon day sun, here they remain protected and hidden from predators until they chew their way out the next day. The females work to dig underground chambers that are often deep enough to escape a plow or rototiller blade. The female lays her eggs and provisions each one with a bit of pollen and nectar. The young larvae develop deep in the earth and overwinter in cocoons to emerge the following summer when the squash blossoms. Squash bees can be found anywhere the squash grows whether on a country farm or city garden.

A squash bee taking in some nectar.

The tomatillo, a member of the nightshade family, may best be known for green salsa, aka, salsa verde. First cultivated by the Aztecs, this native North American plant has its very own specialist pollinator, called a broad footed cellophane bee (Colletes latitarsis). These bees were found pollinating the tomatillo flowers that require cross pollination to bear fruit. This species also pollinates plants in the same family including the ground cherry that was also growing near the tomatillo. Ground cherries like the tomatillo are covered in a papery husk. The yellow fruit of the ground cherry tastes tart and described by some to taste like pineapple. It is delight to eat and is often made into sauces or jams. Like many solitary bees, the adult bees are only active for a short period of time and for many specialist bees that usually coincides with the blossoming of their preferred plant. This cellophane bee can be found only in late July and August when the tomatillo’s and ground cherries are in blossom. These ground nesting bees are known to nest in wet areas successfully because they line their nest with a cellophane like substance that if removed from the ground is reminiscence of plastic bags.

A cellophane bee is a specialist of tomatillo and ground cherry.

Generalists

Leaf cutter bees (Megachile spp.) unlike the previous species on our garden tour are generalist pollinators and can be found throughout the garden on a variety of flowers. Leaf cutter bees are unique for many reasons, most notable are their large mandibles that they use, as their name implies, to cut leaves they use to line their nests and add partitions between brood chambers. Like all bees in the megachile family, which include blue orchard bees, they collect pollen on scopa hairs located on the underside of their abdomen instead of on thier hind legs like most other bees. Lastly, they often hold their wings outward similar to wasps. Look for this dark colored bee throughout the garden. There are many different species that are common in our area and it can be difficult to tell one species from another.

Note the pollen on the scopae hairs on the underside of this leaf cutter bee.

Any walk in the garden is incomplete without mentioning the common eastern bumble bee (bombus impatiens), which is the most commonly found species of bumble bee, anywhere in our region. The bumble bee is a generalist pollinator and the only truly social species of bee in our area, which means they have a queen. The summer garden is full of worker bees gathering nectar and pollen that they bring back to the underground colony to raise brood. By late summer the bees are rearing a new generation of queens and drones. Bumble bees like most of our native bees are better equipped to pollinate native flowers such as tomatoes, another familiar member of the nightshade family. Tomatoes require buzz pollination to shake the pollen from the flower and bumble bees are skilled at acquiring the pollen using this technique. As on any garden tour it is imperative to pay heed to the loud vibrations of the wings that remain motionless as the bee shakes the flower by use of the powerful flight muscles.

A bumble bee buzz pollinating the tomato flower.

Most of the bees already described are relatively large but there are tiny bees appropriately sized to the the smallest blossoms. One tiny sweat bee covered in red pollen from the holy basil is from a family of bees called Lasioglossum also known as small dark sweat bees. This minute insect works undeterred among literal giants such as bumble bees, leaf cutter bees and carder bees. They are not only difficult to see but are even more difficult to identify and certainly their contribution to pollination is under appreciated. Their flight radius ranges from a tenth of a mile to just over a half mile depending on species and size. The smaller the bee the smaller its territory therefore individual gardens and backyards can certainly be essential to the survival of the smallest species.

This small lasioglossum is one of the tiniest bee seen in the garden.

In agriculture there is a symbiotic relationship between the bee and the flower but also between the bee and the farmer who reaps the harvest of successful pollination. The farmer picks the bounty of food that they proudly take to the farmers market. Despite this interrelationship the bee has its own personal reasons to visit the flowers, to gather pollen and feed their developing progeny that will emerge in the coming summer to pollinate the flowers of the vegetables that the farmer replants.

Bees are not the only pollinators at work in the garden here is a fly called a Mydas clavatus that is often mistaken for wasps that they resemble.

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