What’s Buzzing in the Garden?
Plants are the foundation of life on Earth, but our ecosystems would look very different without pollinators. Bees, flies, wasps, and birds all help plants reproduce, supporting both wild ecosystems and the foods we eat. At UBC Botanical Garden, home to around 5,000 plant taxa from temperate regions around the world, we have a unique opportunity to explore how plant diversity shapes pollinator communities.
In the summer of 2025, I worked as a Biodiversity Survey Assistant at UBC Botanical Garden under the supervision of Adriana Lopez Villalobos. With guidance from Dr. Elizabeth Elle, a pollination ecology researcher at Simon Fraser University, I helped conduct field surveys to understand pollinator diversity across the Garden.
Our focus was on one especially important group: bees. While many visitors are familiar with bumblebees and honeybees, these represent only a small fraction of the almost 500 bee species found in British Columbia. Most bee species are solitary, meaning they do not live in colonies with queens and workers. Instead, each female builds and provisions her own nest, often underground or in small cavities. They do not produce honey, but they are vital pollinators and come in an astonishing variety of shapes, sizes, and colors. To the untrained eye, some may even look more like flies, wasps, or ants than bees.
Because many pollinators are difficult to identify in the field, I collected specimens for closer examination under a microscope. Pollinators were sampled using hand nets and pan traps – small colored dishes filled with water and a drop of soap. The blue, white, and yellow dishes mimic flowers and attract a wide range of pollinating insects. We placed sets of pan traps in different areas of the Garden, including forest sites in the David C. Lam Asian Garden, the E. H. Lohbrunner Alpine Garden, and the Garry Oak Meadow Garden.
Over the course of the summer, our surveys resulted in approximately 400 insects that were collected, identified and properly mounted, highlighting the remarkable diversity of pollinators in the Garden. Among them were about 20 species of mining bees in the genus Andrena, 15 species in the family Halictidae, 11 species in Megachilidae, 4 species in Apidae, and 3 species in Colletidae, along with 18 species of hoverflies and a variety of other wasps, sawflies, and muscid flies. With so many pollinators active in the Garden, here are a few especially interesting ones to look for on your next visit.
Mining Bees
Mining bees are among the most common native bees in gardens, though they often go unnoticed because of their small size and brief seasonal activity. Most belong to the genus Andrena, a diverse group of solitary, ground-nesting bees that dig small tunnels in sandy, bare, or lightly vegetated soil. Each female builds and provisions her own nest.
Some mining bees are oligolectic, meaning they collect pollen from only a narrow range of closely related plants rather than from many different kinds of flowers. Although many individuals may nest close together, they do not live socially. Instead, they simply tolerate near neighbours while remaining solitary. These bees are important early-season pollinators, visiting spring wildflowers and helping pollinate crops such as apples, cherries, and blueberries. Their nests are often found near the flowers they visit, and in early spring – before vegetation has grown thick – you may be able to spot the small entrances to their tunnels in patches of exposed soil.
Sweat Bees
Sweat bees may be small, but they are an important part of the pollinator community at UBC Botanical Garden. They belong to the family Halictidae, one of the largest bee families in the world, with species found on every continent except Antarctica.
This is an incredibly diverse group. Some species live alone, while others share nests or live in more socially organized groups. In some cases, their social behaviour can even shift depending on the season, elevation, or food availability. Sweat bees also vary widely in appearance: many are tiny and easy to miss, while others shine in brilliant metallic green.
These bees visit a wide range of flowers and play an important role in pollination. Their unusual name comes from the fact that they sometimes land on human skin to sip salts from perspiration. While that may sound alarming, sweat bees are usually very gentle and rarely sting unless physically threatened.
Mason Bees
If you’ve ever seen a mason bee (Osmia spp.), you may have mistaken it for a fly or a flying ant. Many mason bees are fuzzy and metallic blue, making them distinctive but easy to overlook. They often nest in small holes in wood, and it is a common misconception that they bore into the wood themselves. In fact, mason bees use pre-existing holes, often ones left behind by other insects.
Mason bees can sting, but they are not aggressive and are unlikely to do so. They are also extremely effective pollinators, making them an excellent addition to most gardens. To see them in action, visit the Garden’s forested areas in early summer, where they may be nesting in fallen trees.
Leafcutter Bees
If you’d prefer to stay in more open areas, keep an eye out for leafcutter bees (Megachile spp.). As their name suggests, they use their strong jaws to cut neat circular pieces from leaves, often from plants in the rose family, to line their nests in tunnels, hollow reeds, and holes in wood.
Although they do cut into leaves, leafcutter bees do not cause serious damage and are generally considered beneficial. Visit the Alpine Garden in late summer and you may spot one carrying a piece of leaf back to its nest.
Wool Carder Bees
One particularly fascinating species is the wool carder bee (Anthidium manicatum), which was introduced from Europe. Females use comb-like mandibles to scrape hairs from fuzzy plants such as lamb’s ears and use them as nesting material.
You are more likely to notice the larger, flashier males and their territorial behaviour. Males aggressively defend patches of flowers, sometimes ramming other pollinators that get too close. Although they can make life difficult for other bees trying to forage, male wool carder bees do not sting and generally leave people alone. If you’d like to witness this behaviour firsthand, visit in August, when males are actively defending their territories.
Cuckoo Bees
One especially interesting group found in the Garden is the kleptoparasitic bees, often called “cuckoo bees.” These bees are not a single natural group. Instead, kleptoparasitism evolved repeatedly and independently across different bee lineages. Most cuckoo bees belong to the families Apidae and Halictidae, with well-known examples including the apid subfamily Nomadinae and halictid groups such as Sphecodes. Kleptoparasitic species are also found in Megachilidae, showing that cuckoo behaviour occurs across several major bee families rather than in just one branch of the bee family tree.
Unlike most bees, cuckoo bees do not build their own nests or collect food for their young. Instead, they lay their eggs in the nests of other bees. Their larvae then consume the stored pollen and, in some cases, the host’s offspring as well.
Because many kleptoparasitic bees parasitize only specific hosts, they can also tell us something about the bee community around them. For example, our surveys found Coelioxys bees, which target leafcutter bees. These bees (Images 5, 6, and 7) have distinctive pointed abdomens, unlike the rounded abdomens of most bees. This pointed tip helps females place their eggs in or near the host’s pollen mass, sometimes before the host has finished provisioning the nest.
While parasitic animals often have a negative reputation, the presence of kleptoparasitic bees is actually a positive sign – it suggests a healthy and diverse ecosystem.
Image 7 and 8: Coelioxys sodalis collected by Elizabeth Elle and Grace Gooding. Photo credit: Mina Lander
Bonus “Bees”: Hover Flies
Another pollinator you’ll find here is not a bee at all – but it can be very convincing.
Many harmless hoverflies have evolved to resemble bees and wasps, an adaptation known as mimicry that helps protect them from predators. And it is not just predators that are fooled: you might mistake the fuzzy yellow narcissus bulb fly for a bumblebee if you do not look closely. To see this mimicry in action, visit the Food Garden.
Hoverflies feed on nectar and pollen, making them some of the most important pollinators after bees. As their name suggests, they are often seen hovering over flowers while foraging. Look for black-and-yellow striped insects with especially large eyes – if you look closely, their eyes may remind you of a house fly’s.
How You Can Support Pollinators
The next time you visit UBC Botanical Garden, take a moment to look closely at the flowers around you. You may notice that the Garden is not only full of beautiful plants, but also alive with the insects that help sustain them.
If you’d like to support pollinators at home, consider:
- Planting a variety of native and non-native flowering plants
- Avoiding pesticides
- Ensuring there are blooms throughout the growing season
To learn more about Pollinators of southern British Columbia, visit Elizabeth Elle Ecology. If you would like to see the full list of species found in our biodiversity surveys, you can explore the dataset here.
Written by:
Grace Gooding, Biodiversity Survey Assistant
Adriana Lopez Villalobos, Research Technician GIS
