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The Quarterly Buzz

Updated: Feb 18, 2022

Newsletter of the Native Bee Society of British Columbia October 2021

Volume 2 | Issue 3


Editors-in-chief: C. Thuring & M. Marriott

Contributors: Christine Thuring, Marika van Reeuwyk, Pat Holmes, Lori Weidenhammer, Josh Thompson, Cassie Gibeau

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Introducing: The Quarterly Buzz

Our New Newsletter Name

by Christine Thuring, Co-editor and NBSBC Secretary

We are so pleased to have a new name for the NBSBC quarterly newsletter! After our first five issues, it became clear that "Quarterly Newsletter for the Native Bee Society of BC" was quite a mouthful. We launched a contest and received numerous fabulous suggestions, including Anthophilings, The Nectar Enquirer, Buzz 4 BC Bees, The BC BeeLine, and BC Melittophiles. Many thanks to all who participated! The selection process involved the Board voting on their favourite 25 submissions, from which the top 3 were shared on social media for a vote from our followers/ membership.

Congratulations to Shira, who submitted the winning name, The Quarterly Buzz, and won a bumble bee nesting box! Shira currently lives in Calgary and is the driving force behind a new venture, The Urban Pollinator Project. This pollinator-focused advocacy project focuses on rewilding the Bow River riparian corridor and was one of over 100 proposals that made it to the finals of the Mayor's Innovation Challenge.


Christine Thuring is a founding board member of the Native Bee Society, and co-editor of the quarterly newsletter from its inception.


Annual General Meeting, Dec 2021

by Marika van Reeuwyk, NBSBC Vice President

It’s hard to believe our third year as a society is coming full circle! Our third Annual General Meeting will be held this December over Zoom. Stay tuned for the date and time.

If you’d like to get involved with the Society, now is a great time to start thinking more about this. Committee volunteers are welcome any time. Board members must be nominated; nominations can be sent via email by Dec 1st.

As ever, our AGM will feature stimulating talks to offset the formalities. Taxonomist and founding board member, Lincoln Best will tell tales of “Weird Wild Bees of BC”, which will appeal to novice and experienced bee enthusiasts alike. As well, founding board members Lori Weidenhammer and Tyler Kelly will share some of the exciting insights and most brilliant submissions they’ve observed on Bee Tracker, a project they’ve initiated on iNaturalist (recall our feature about this in our Summer newsletter). We’ll also provide an overview of upcoming events this fall in Metro Vancouver and the Kootenays.


Seeds to Bees Winter Workshop Series

The Native Bee Society of BC is excited to host a series of workshops this winter related to planting for pollinators. From home gardening to native plant propagation to restoration, learn from experts in the field about different ways you can support pollinators in your community!

Workshop 1: Beginner Seedy Skills for BC Bees

Basic Seed Saving and Growing Tips for Plants that Support Native Bees in Your Garden

Image 1: Agapostemon sweat bee on a cosmos flower. Image 2: Andrena prunorum on buckwheat at UBC Farm. Photos: Lori Weidenhammer

In the first workshop in this series, Lori Weidenhammer, aka Madame Beespeaker, will share fun tips on how to get hooked on saving and growing seeds for plants that provide bees with pollen and nectar. These are empowering skills that can save you money and fill you with the joy of helping create gardens that increase biodiversity. In order to be a successful seed saver and grower, you need to know about the basics of pollination, and which plants are best for saving our BC native bees. Learn how to help bees (along with butterflies, birds, and other critters) by growing plants that a generous seed producers, so you can share them with your friends and family.

Date and time: Thursday, Oct 28, 7:00 pm Zoom link (if you need a call-in number, please email us:


Lori Weidenhammer is a founding member of the NBSBC. She has been fascinated with seeds ever since she was a child in her mother’s prairie garden. She is the author of Victory Gardens for Bees: A DIY Guide to Saving the Bees published by Douglas and MacIntyre. As a food security volunteer and activist, Lori works with students of all ages on eating locally and gardening for pollinators. Lori is originally from Treaty 6 Territory in Saskatchewan the original lands of the Cree, Saulteaux, Dene, Dakota, Lakota, Nakota and the homeland of the Métis Nation, and is grateful to live and work in unceded territory of the Coast Salish nations. Lori's web site is Victory Gardens for Bees (

Follow Lori on Instagram @beespeaker


Workshop 2: Native Plant Propagation Techniques

by Joshua Thompson from Plan Bee Native Plants

Native plants are crucial to restoring ecosystems and for supporting native bees as well as all life unique to our part of the world. Learn about the different techniques involved with growing and getting different species of native plants to germinate from seed.

Date and time: TBA Access to the workshop will be shared via social media and an email to our members


Workshop 3: Restoration for Pollination

by Valerie Huff, MSc of Kootenay Native Plant Society & KinSeed

Plant-pollinator mutualisms are a critical ecosystem function that sustain natural habitats and support the food web in terrestrial ecosystems. Pollinators, mainly insects, transport pollen among flowers to ensure the production of viable seed, sustaining native plant communities. Interest is high in supporting these plant-insect interactions through establishing native wildflower meadows. In this webinar, Val will describe how the Kootenay Native Plant Society approaches the question of “What should I plant for pollinators?” in a restoration context. She will guide you through how KNPS developed theirr list of priority plants for the Pollinator Pathway Climate Adaptation Initiative in the Lower Columbia region of British Columbia and provide practical examples and tips for regional restoration interests.

Date and time: TBA Access to the workshop will be shared via social media and an email to our members.


Caring for Cavity Nesters

Strategies and learnings from a seasoned wild bee caretaker

by Pat Holmes


I first met Pat Holmes through my friend and fellow NBSBC Board Member, Martina Clausen when I was looking for some locally sourced bee cocoons to populate a bee hotel built by youth in a program I was leading. Martina connected me with Pat, and I was excited to learn she has a thriving garden and cavity-nesting bee set-up in her backyard in North Vancouver. Pat’s homegrown oasis attracts many diverse wild bees, invertebrates, birds and wildlife. A large population of bees from the Megachilidae family have taken up residence in her homemade bee houses, including mason bees (Osmia spp., her most common residents), leafcutter bees (Megachile spp), and wool carder bees (Anthidium spp).

Pat has been stewarding cavity-nesting bees in her backyard for over a decade. Through research, learning and practice she is constantly trying to better her techniques to minimize time and increase bee health and survival. It's been a welcome gift to exchange learnings with someone who has been working in relationship with cavity nesters for so long. Pat also joined the Native Bee Society of BC membership when we established in 2019!

Pat’s bees came from the wild - she set up some homes and they just moved in. Her husband Andrew kept having to build her more and more homes and cavities to keep up with her growing population. Today, Pat tends to over 1000 cocoons annually between her home residence in North Van and her cabin on Hornby Island. She keeps about 200 at each place then gifts the rest to EYA and other local people interested in starting up their own cavity nesting bee establishments.

Now is the time of year that those of us managing cavity nesting bee homes need to put in the work to mitigate parasitisation and disease, so I asked Pat to share some of her tried and true learnings and techniques with us.

-- Marika van Reeuwyk, NBSBC Vice President

Caring for cavity nesters: strategies and learnings from a seasoned wild bee caretaker

Images: Bee Houses in North Vancouver, Pat Holmes, Bee Houses on Hornby

A year in summary: managing cavity-nesting bee houses

Although cavity-nesting bees are easy to manage, some work is required to keep them healthy and able to continue their valuable work of pollination. Their life cycle allows for flexibility when it comes to cleaning their cocoons and setting up their space for the next year.

Cavity-nesting bees hatch in the spring, usually late March or early April and are mostly finished by mid June. They prefer their houses to be on an east or south facing wall, they need access to flowers of some description and soil and water. In North Van my bees have plenty of fruit trees and shrubs plus flowers but on Hornby they only have the woods and a large maple tree, both areas work well. I set my boxes out in mid March starting at about 4 feet high and they go up to around 8 feet - there are a lot of cats in our neighbourhood and the bees are vulnerable if they are too close to the ground.

I will clean out my bee houses anytime after early November, wash my bee cocoons and keep them safe and cool until the following spring when I set them out to hatch. They can be kept in glass jars with air holes in the lids either in the fridge or an outside garage or shed, preferably north facing and cold. Freezing temperatures don’t seem to affect them but if they get too warm they can hatch early.

[While mason bee (Osmia spp) cocoons are “waterproof”, leafcutter bee cocoons are encapsulated in a brood cell that is “wallpapered” with leaves. This leaf enclosure is not waterproof, so whether or not you wash your mason bee cocoons, it is typical in leafcutter bee cocoon management to simply use a dry toothbrush to remove frass and other debris. Its still important to sanitize trays to protect from fungal diseases].

General mason bee cocoon cleaning practice

Originally I washed my mason bee cocoons in the manner used by the David Suzuki Foundation, using a sieve and mild bleach solution. After time I became disenchanted with this method and felt it was unnatural and difficult to keep the cocoons cool yet dry enough not to get moldy. Also, the mites that cling to the cocoons don’t seem to fully let go in a bleach solution, they are incredibly tenacious.

Now I wash my mason bee cocoons by hand, I inspect the cocoon for any holes or mites and give them a cursory rub with my fingers to remove the brown frass. If they have a hole I discard them and if they have mites I give them a gentle scrub with a small brush or soft toothbrush which is the most efficient way to remove mites. I will keep my unaffected bees separate from the ones that had mites so I can check the mitey ones again before I set them out to hatch.

Cleaning the bee houses has been a time consuming business for me for years but using the compostable cardboard tubes in my wooden houses means that they remain clean and has really reduced my workload.

Three common parasites in cavity-nesting bee houses

As I mentioned before, mason bees are susceptible to mites, which are really interested in the pollen that the bees set in their houses for their larva to feed on. The mites multiply by eating the pollen [left by the female] and the bee larva starves. Then once hatching commences, if the tubes aren’t cleaned, the emerging bees have to crawl through a tube of mites which will jump onto the bees and the whole process begins again.

Another predator that the mason bees face is a parasitic wasp. These small wasps have a large ovipositor, they crawl into the bee tubes and drill a hole in the cocoon with which to deposit their eggs into the bee larva.

If this isn’t bad enough, a new predator from Europe has become prevalent in Vancouver, the houdini fly [Cacoxenus indicator]*. They sit nearby and wait for a female to leave her tube, they then zip in and lay their eggs on the pollen ball and zip out. A houdini fly or 2 can reduce a thriving colony of mason bees to zero in two seasons.

Image 1: Pollen mite infestation in a bee tube. Image 2: Parasitic wasp larvae and dead adults in a bee tube. Image 3: Houdini fly larvae and frass. -- Photos: Pat Holmes

How to protect cavity-nesting bees from parasites

I manage the mites by making sure my bees are clean to begin with every season. Mites are very hard to deal with- I've tried freezing the wooden houses, cooking them in the oven, washing them in water with bleach. The mites survive!! For me, preventing them from getting in to begin with [using the cleaning method mentioned above] is easier.

I manage the wasps by trying to making sure they can’t access the cocoons by traveling sideways down the bee tubes, which is easier said than done. Currently I use cardboard tubes which I get at WildBirds and set a tight fitting paper tube inside them. That way I can reuse the cardboard tube provided it isn’t contaminated at the blind end by mites.

The Houdini fly* is a whole new problem. I’m trying to control them by cleaning out my tubes and when I see their golden strands of frass and their little yellow larva I dispose of them in the garbage. I’ve had them in North Van for about 3 years but haven’t seen them yet at my cabin on on Hornby Island.

Hatching out your bees

It’s lovely to have a wooden hatching box with a hole but so far I just use a sturdy cardboard box with 2 holes for them to crawl out of, set in the upper corners of the box, around the same diameter as their bee tube.

The male bees tend to hatch first, they are very cute with white tufts of hair on their foreheads. They hang about waiting for the females to hatch, some will even sit in the hatching box to grab a female and mate with her before she’s even had a chance to try her wings.


Pat Holmes has had a life-long love affair with bees and started getting serious about mason bees in the last 10 years. A retired nurse, married mother of 4 children and 2 grandchildren, she lives in Lynn Valley. She is a keen gardener and, in recent years, she has become more interested in plants that suit native bees than in showy flowers and shrubs. Her friend, Taren, first introduced her to mason bees over 15 years ago because she was making mason bee houses and selling them at craft fairs and trade shows. She was definitely ahead of her time!