Colour for all seasons

Pause here to look at the varied collection of flowering plants along the riverbank. What colours do you see? Purple, red, white, yellow – depending on the time of year, flowers will have emerged: Woodland Sunflower (Helianthus divaricatus), Culver’s Root (Veronicastrum virginicum), Coneflower (Echinacea purpurea), Goldenrod (Solidago species), New England Aster (Symphyotrichum novae-angliae), Bee Balm (Monarda species) and Yarrow (Achillae millefolium). You may see some colourful butterflies or moths, who rely on the pollen and nectar of these flowers and in turn help to fertilize the plants so that seeds and fruits will be created.

What do you hear? Do you hear the buzzing of the Eastern Common Bumble bee? It makes quite a racket when it sticks its long tongue into a tubular flower and starts vibrating its wings and mid- body to shake out the pollen. In contrast, the honeybee is quite quiet as it goes about grazing on flower pollen. The syrphid or hoverfly is also a quiet forager, but buzzes when it hovers its wings in transit to the next flower. The native Eastern Common Bumblebee is quite common along the Riverwalk and is an important pollinator picking up large quantities of pollen on its fuzzy hairs and arriving early in the season looking for pollen and nectar to eat and take back to its nest in the ground.

The other insects found in large numbers along the Riverbank are the Syrphid flies. You would be forgiven if you mistook the hoverfly for a wasp. It has the telltale black and yellow banding of a wasp or bee but it's a disguise that nature has given it for protection. You’re meant to give it respect and stay clear so it can do its important job of collecting pollen and fertilizing plants, particularly native plants. Without a stinger however, it can't sting you and without jaws it can’t bite you, but unless you look very carefully you wouldn’t know that. The Narrow-headed Marsh Fly (Helophilus fasciatus), is one of the many species of syrphid flies found on the riverwalk as early as April and active into October. The syrphid fly's maggot-like larvae devour aphids and thrips like they were popcorn which should also make them a gardener's friend.

This tour stop has a terrific diversity of flowering perennials and is an excellent example of how to design a “three season flowerbed" that supports pollinating insects, birds and mammals throughout the entire growing season. Be sure to visit this section of the riverbank in spring, summer and fall to witness an ever changing parade of colourful blooms.

You may also spot an invasive plant, Purple Loosestrife, close to the water's edge. If you have questions about invasive plants on your property, the Ontario Invasive Plant Council has a very informative website to help you identify (and report, if necessary) invasive plants. They also have developed a “Grow Me Instead” plant guide designed for our northern gardens, which suggests native plants suited to our region which can be planted instead of invasive ornamental plants such as Goutweed, Periwinkle, Lily of the Valley English Ivy.

U-Links Species Profile:

Eastern Common Bumble bee, Bombus impatiens

As aforementioned in its name, B. impatiens is the most common bumble bee to encounter while out and about in the spring and summer (Williams et al., 2014). Some bumblebees are difficult to distinguish from the naked eye, and the eastern common bumble bee can be confused with another species Bombus bimaculatus, which is also known as the Two spotted Bumble bee (Williams et al., 2014). The difference between the two Bumblebee’s lies with where the yellow hairs turn into black hairs on it;s abdomen, with the two spotted bumble bee having more yellow colouration towards the middle of its abdomen, compared the the Eastern common bumble bee whose yellow colouration ends closer to where the thorax and the abdomen connect. This however is difficult to tell when they are out and about due to how similar they are.

colour shape and body size all change with the sex and the role of the bee in the colony. The Largest of all the bees is the queen, ranging roughly 21-23mm in body size, whereas the workers and drones are 9-14mm in body size (Williams et al., 2014). Drones will sometimes sport two yellow dots on the end of its abdomen, close to the stinger.

The Eastern Common Bumble Bee, as are the majority of bee species, are a eusocial species, with roles as scavengers and nest dwellers. Scavengers are the bees you will see in your gardens, frantically roaming around various flowers and plants in search of nectar. The Eastern Common Bumble Bee scavengers are some of the most active feeders, consuming nectar a lot more than other species due to how deep into the flower their tongues can reach (MacKenzie, 1994). This also makes them significantly superior pollinators to other species, as they will vibrate heavily while feeding, resulting in more pollen to stick to them, which they transport at high rates to other flowers. The Eastern Common Bumble Bee, as a result of their effective pollinating, are great for gardens as they will pollinate plants that traditionally have a harder time releasing their pollen (Vaudo et al., 2016). This generalist species can be found on practically any flower or fruit tree, making them incredible helpers for gardening and native plantlife. Asters, goldenrod and thistles are some of their favourite native plants that they can feed on (Williams et al., 2014).

Their nests are atypical to the traditional bees nest as this species will burrow underground (Williams et al., 2014). The Eastern Common Bumble Bee will set up nests in all sorts of environments, whether it be urban, forested, grasslands, farmlands, parks or wetlands.

U-Links Species Profile:

Narrow-headed Marsh Fly, Helophilus fasciatus

The black and yellow banding on insects is a strong indicator of a bee or wasp to both humans and animals alike.due to this predisposition, the infamous bandings of bees and wasp has caused many of us to become cautious around these insects, in hopes of avoiding being stung. Although there is reason to react in such a manner, one insect group has utilized this black and yellow warning as a disguise and that group is the syrphid. Despite their colouration, they do not possess a stinger and cannot bite either as they do not have the sharp mandible that are brandished by wasps, therefore making them harmless to humans.

Syrphids are the largest fly family and have a range of approximately 6000 individual species that can be found around the world. Their range is extensive, populating all continents with the exception of the antarctic and some remote islands in the ocean (Doyle et al., 2020).

Helophilus fasciatus is one of the most common syrphid species found along the east coast, but can be confused sometimes with its relative, Helophilus latifrons, also known as the Broad-headed Marsh fly (Skevignton et al., 2019), both of which can be found along the Minden Riverwalk. H. fasciatus is roughly 10.8-15.2mm in length, but is wider than some other species of syrphids found at the site, such as T. geminatus. The Narrow-headed Marsh Fly has one of the longest active flying times, being one of the first species to fly around in the early March months and will stay active until as late as October (Skevington et al., 2019).

Syrphids, also known as hoverflies, are known pollinators and can carry pollen for greater distances than bees and wasps due to not having constraints to a hive or nest (Doyle et al., 2020). During spawning season, the females will look for plants overhanging ponds, where they will lay their eggs in the vegetation. Once hatched the larvae, known as rat tailed maggots, will dive into the water, where they will begin their development phase, eventually metamorphosing into their adult form (Skevington et al., 2019) that you commonly see on the walk.

Researcher: Caleb Brown, Trent University