NATIVE BEES: WHO ARE THEY, WHAT THEY DO, AND HOW TO KEEP ‘EM HAPPY

Presented by Anthony Melathopoulos (Dalhousie University)

There is much more to those little buzzing creatures than meets the eye and more of them than many might realize.  I’m referring to native bees; there are hundreds of species in Nova Scotia ranging from very small to surprisingly large! Honeybees, one of the most common bee species that may come to mind, are however a domesticated species.

Unfortunately all native bee species around the globe are in decline largely due to anthropogenic causes:  habitat fragmentation and pollution.  Anthony Melathopoulos hosted the Native Plant talk on March 15, and discussed how to recognize native species of bees, their role in the environment, and how to house them and keep them content in your own gardens.

First, a bit of history:

One hundred and fifty million years ago native bees separated off from wasps on the evolutionary path. They co-evolved with many of the angiosperms (flowering plants) they are commonly associated with.  They are dependent on plants for their entire livelihood.

Who Are They?

As there are over a hundred different species in Nova Scotia, many bees do not look like the typical black and yellow striped critters that come to mind and some creatures, such as yellow jackets, that have this colour pattern are in fact wasps, not bees.

To distinguish bees from others it is important to note that they are hairy, have two pairs of wings, and sturdy antennae. Compared to flies they have a longer abdomen, larger eyes on the side if their head, and can fold their wings behind their back when they are resting.

Bee colonize consist of a queen, workers, and drones. The queens are about the same size as the workers just with a larger abdomen and they do all the reproducing.

There are around 400 species of bees in Canada with a wide range of appearances. The main species discussed were: leafcutter bees, wild bumblebees, digger bees, mason bees, and sweat bees.

Leafcutter bees are not social bees. They are quite small; fly size or smaller.  They are black to bluish in colour, carry pollen on their abdomen, and nest in holes made by beetles in wood.

Bumblebees are a medium to large size bee. They are a social species and often occupy abandon rodent dens. They carry pollen on their legs, and their colouring is species specific.

Digger bees are a solitary, small species that reside in the soil. They are rather specific when choosing plants and can be identified by their unique velvety area between their eyes.

Sweat bees are a small bee with a metallic/ iridescent gold or green colouring. This species is both social and solitary and lives in the soil or soft wood.

What Do They Do?

Bees make honey yes, but they also pollinate flowers, an essential duty for maintaining life on Earth. The processes involved, their routines, and life cycles are quite interesting.

Most bees are not picky when choosing which flowers they visit and move from bloom to bloom as the season goes in. Some bees however, are specialists. For example some live exclusively off willows.

With the pollen the bees collect they pack it into honey combs and use it to feed their young.  (It is interesting to note that honey from different flowers is different colour and even tastes different!)

Reproduction habits vary among species. Three species’ habits that were highlighted are: bumblebees, leafcutter bees, and mason bees.

Bumblebees are seasonal and live underground over winter. When it is warm enough they emerge from their den and begin to gather pollen to make wax and honey. They only have about four babies which are very small at birth. They grow throughout the season and are the largest in the fall when they mate and the cycle continues again.

Leafcutters lay multiple eggs inside a tube such as a twig and the babies chew their way out.

Mason bees make a cocoon in preparation for the winter.

Different species emerge from their dens at different times in the season. In April the mason bees and digger bees come out, followed by the leaf cutters and bumbles in mid-season, and finally the sweat bees near the end of the summer.  Because of this alternating pattern, in order to support bees in your garden through the season, you need to ensure there are successful blooms to accompany them.
This leads us to:

 How to Keep Them Happy

An important factor is there needs to be enough plants and a diversity of flowers within the garden as not all bees can use the same flowers.

Providing nesting sites and water can ensure happy bees!
Many bees nest in holes and making homes for them can be simple:

- take a block of wood and drill holes all the way through the block
- if the block is in two pieces you can break it open and get the cocoons to keep them safe

-plexiglass used as a cover allows for observation of them in their holes
- securing a bunch of straws together will attract bees that use tubes for nests such as the  leafcutters.

These are just some basic ideas. Visit the how to build nesting boxes blog for more ideas and insights on how to share your summer season with bees!

 

Written by Kaitie Porter

BUILDING HOMES FOR NATIVE BEES

NATIVE BEES-

Over 60 species of native bees have been identified in Eastern Canada and Maine’s wild blueberry production regions.

“Pollinators are a diverse and fascinating group of animals. In addition to their beauty, pollinators provide an important link in our environment by moving pollen between flowers and ensuring the growth of seeds and fruits. The work of pollinators touches our lives every day through the food we eat. Even our seasons are marked by their work: the bloom of springtime meadows, summer berry picking, pumpkins in the fall.

There are 4,000 species of native bees in North America. Together they form the most important group of pollinators. Like all wildlife they are affected by changes in our landscapes, especially the loss of nesting sites. Bees make nests in which they create and provision brood cells for their offspring. In many modern landscapes, a desire for neatness has usually resulted in the removal of bare ground, dead trees, and untidy corners of rough grass—all important nesting sites for bees.”

-Matthew Shepherd, The Xerces Society of Invertebrate Conservation.

BUMBLE BEES-Bombus lapidarius

Bumble bees have an annual colony cycle that begins early in the spring when the overwintered queens emerge from their hibernation sites to feed on spring flowers and search for a suitable location for their new colony. Once the site has been found, the queen collects pollen, forming it into a lump that she lays her first brood of 7 or more worker eggs on. The pupation takes about 21 days. Once hatched they feed on the pollen lump, and additional pollen and nectar collected by the queen. This first group take over pollen and nectar collection while the queen continues to lay successive broods of worker eggs. By mid-summer, a colony contains between 20-100 workers, depending on the species. It is around this time that the colony begins to produce males and queens. The new queens leave the nest, and after mating dig 5-10 cm into the soil for hibernation. As autumn approaches, the remainder of the colony declines and dies. The hibernating queen emerges the following spring to begin the cycle again.

-Department of Agriculture, Aquaculture and Fisheries

BUMBLE BEE NESTING BOX CONSTRUCTION -

*this is a great video that goes through the steps of building the box.

You will need

Untreated wood 2×8” and a smaller piece for the interior wall approx.  2×6”  cut into and some plywood or some sort of thin wood that you can use for the floor and roof.

2×8” board

-2x 14” lengths

-2x 7” lengths

2×6” board

-1x (7x 5”) piece (this can be any size as long as it’s shorter then 8” high)

ply wood

1x (10.5×14”) inch board (floor with 2” inch over hang)

1x (8.5×14”) inch board (roof)

supplies

- 3/4” plastic hosing

- screws + drill

- 1” drill bit

- wood glue

- cotton batting (available in the quilting/upholstery section of fabric stores)

*Glue all boards as you go so that they will be air tight. Bumble bees don’t like drafts.

This is the finished box minus the roof.

* When you first notice bumble bees in the spring place your new bee box outside in a safe, undisturbed place. Because bumble bees usually live in holes underground you will want to bury your box a few inches into the ground and extend the tube gently towards the surface. Only 1 in 4 boxes are occupied by bumble bees. If you’re box is not chosen take it inside and store until next spring when you can try again.

MASON BEE NEST BOX BUILDING-

MASON BEE- Osmia

Solitary Bees include leafcutter bee, mason bee or alkali bee. They emerge each spring never having met their mother. They develop in a stem, soil tunnel, or in an abandoned burrow made by another insect.

Each tunnel is filled with a row of compartments with an egg and mass of nectar-pollen. These compartments are sealed off with either leaves, clay or mud. The end of the tunnel is sealed with a heavier plug to keep the eggs safe. After consuming the larva’s share of pollen, the developing bee will enter diapause, passing through the rest of summer, fall and winter as a prepupa which is a sort of suspended state. Then as spring approaches they complete rapid pupal development.  Once they complete their metamorphosis and become adults and emerge from their compartment to mate right away, ideally with individuals from a different nest. The male dies soon after mating, and the female then does the environment an invaluable service of collecting pollen from the flowers that are blooming around her. The pollen collected is used to provision her own nest as the other of the next generation.

Collecting Knot Weed

*Please make sure that you remove all seed from your cuttings so that you do not accidentally spread the unstoppable knot weed.

1. Find a patch of knot weed

2. Cut stalks just below the lowest node.  A node is the area of a plant’s stem from which the leaves grow.

3. Trim off branches from the main stem.

4. Trim stalks into smaller lengths that are 6-8 inches,  always just below a nod so that one end is closed.

5. You will need approximately 25-40 stalks for one nesting box.

BUILDING A MASON BEE NESTING BOX

You will need

- 2 pieces of 2×8” untreated wood cut into 13” lengths.

- 2 metal brackets

- weather resistant rope

- screws

- knot weed, bamboo, raspberry canes or any naturally hallow plant. Cut into approx. 6-8 inch lengths.

——————-

1. Prepare your knot weed or other hallow stemmed plant into lengths that are 6-8″ long.

2. Screw your roof together and attach the brackets on the underside of the roof to be able to secure it to a surface.

3. Lay the hallow stalks in the roof, now looking at the stalks as though they are water in a bath tub mark four dots that are just below the water line. This will allow you to tightly fasten them in with rope in a moment.

4. Drill holes where you made your marks.

5. Lay the hallow stem lengths with the openings facing the front without the brackets.

6. Thread the weather resistant rope through the holes.

7. Tighten the rope, and tie it so that the stems are securely in place.

8. You’re done and ready to mount your new nesting box in a safe place facing east or southeast to catch the morning sun.

BEE VIDEOS

*Mason Bee Hotel video

*Leaf Cutter Bee video

RESOURCES

The Xerces Society for Invertebrate Conservation

Pollination Guelph

Toronto’s Wild Bee’s

Rebecca Singer