Bee boxes, houses, condos and hotels…Part 2: The photos

by Christine Hanrahan

It is said that a picture is worth a thousand words and, bearing that in mind, I am posting some photos of a couple of bee nesting structures.

The large nest box made by Agriculture and Agri-Food Canada scientists has holes of varying sizes and contains rolled up tubes of paper that can be removed. At the end of summer, these paper tubes would be placed in a container in a refrigerator or unheated building for the winter and brought out in spring in a place where the bees can emerge safely. The nest box itself would be disinfected before being re-used.

The old bee box from 2009 was made for us by Bruce Burns and used as part of a display on pollinators. Later, in mid-summer, we placed it in a south-facing site, protected from intrusion and, within days, leafcutter bees (Megachile) were using it.

Bee bundles are another method of providing homes for tunnel-nesting bees and, in this photo, you can see how the bamboo bundles were placed inside a plastic plant pot for protection from the elements.

The next two photos are of two different bees using the bee boxes. The Megachile is checking out the old box in 2009, while the mason bee is investigating the newer box in 2012.

There is a close up of the rolled paper tubes in this next photo.

The last photo shows a tree swallow nest at the FWG, removed when the box was cleaned in early November. Inside were many dead bumble bees and, beneath the straw of the swallow nest, were many “honey pots” made by the bees.

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Bee boxes, houses, condos and hotels…

by Christine Hanrahan

This is a simple overview of various types of accommodations for bees. I won’t be providing instructions for building bee boxes, but I do provide a reference below for the best all-round source for creating different types of bee houses.

Much media attention has been given to declining honeybees (Apis mellifera), but less well-known is the decline in many native bee species, such as bumble bees (Bombus) and others. Our native bees are facing habitat loss, pesticide contamination, disease, and who knows how many other problems. Studies are ongoing with more research devoted to this issue.

The good news is that people are becoming more aware of bees as beneficial. I spoke with a pest control official recently who said that although he still gets calls from people worried about bees, such calls are fewer than in the past. The ongoing media attention about disappearing honeybees and subsequent attention paid to bees in general, and their importance to pollination, has moved this group of insects into a more benign category.

One indication of the changing attitude is the recent interest in placing bee boxes (bee nest sites) in gardens. Although I am happy about this trend, there is also a downside. Buyers are not usually told that if they want to help bees, nectar rich plants must be available or bees won’t be interested. The importance of hygiene in bee boxes is rarely discussed either. Unfortunately, some commercially produced bee boxes are more concerned with making cute ornamental art for the garden than with the requirements of bees.

Many of our native bees are ground nesters and won’t use bee boxes. This brings up a whole different issue, which I’ll leave for another time, as this article is looking only at tunnel-nesting bees, the ones most likely to use bee boxes.

The natural nesting sites of these bees is the hollow stems of plants, such as wild raspberries, or holes in standing dead trees (snags). When we build bee boxes for them, we are emulating their natural nest sites, much as we do for cavity nesting birds when we install nest boxes.

The most common tunnel-nesting bees we see around the Ottawa are leaf-cutter bees and mason bees (both in the Megachilidae family). These are the ones that will be most attracted to bee boxes. Bumble bees may also be attracted to man-made nest sites. At the Fletcher Wildlife Garden (FWG), a newly installed bee box in summer 2009, attracted leafcutter bees (Megachile) within days. In 2012, scientists from Agriculture and Agri-Food Canada (AAFC) placed a number of bee boxes as well as bee bundles, around the garden in a variety of sites, and these too were very well-used, particularly the nest boxes.

There are innumerable ways to provide nesting sites for these bees, the simplest being to leave snags standing, and to grow plants that bees would use in the wild for nesting. Creating artificial nesting sites is the other option, and ways and means are varied and many.

First and always, when making any bee structure, think of hygiene, as parasites and disease are a serious problem for bees. With simple bee blocks, essentially a wooden cube with holes in it, there are two options: you can replace them every year or you can use removable cylinders in each hole. These can be straws or rolled tubes of paper, which can be discarded when the bees have finished nesting. The bee block can then be disinfected, instructions for which are given in the native pollinator book listed in references below.

Bee blocks work best if they have holes of varying diameters (to accommodate different bee species) and of sufficient depth to allow bees a long tunnel to work in. Some people suggest drilling the holes slightly upward to prevent rain from getting in. Logs with drilled holes can also be used for this same purpose. Old, weathered logs are best as they emulate the snags that bees would naturally use. At the FWG, I’ve noticed bees making nests in some of our old well-worn wooden posts (used for habitat signs) and the split-rail fences.

Other types of simple nest accommodations include bee bundles, which can be made from lengths of hollow stems, such as bamboo, phragmites (abundant in the region, although very invasive so make sure you don’t distribute the seedheads elsewhere), cup-plants. These are best if situated within some sort of cover (large black soft plastic plant pots were used by scientists who set up bee bundles at the FWG in 2012) to protect them from rain and located in a sheltered site. At the FWG, I’ve noticed mason bees checking out plants for nest sites, and they also used the AAFC bee boxes.

Bumble bees frequently nest in the ground, but they will also nest in piles of stones, brushpiles, under decks, and even in bird nest boxes (which I’ve seen several times at the FWG). I’ve also seen them nesting in the foundation of my house and in sheds. In other words, while their sites are varied, what they are seeking is a warm, dry, sheltered cavity.

Finally, some very creative ideas for creating “condos” or “hotels” for bees (and other insects too) come via the Pollinator listserv. These examples show how bee and insect condos can be constructed fairly simply, using found objects, such as plant stems, bricks, logs, etc. Ingenious designs from across Europe are shown, ranging from small and simple to quite large and more elaborate, all of which can be used and adapted for our area. General information about cleaning out bee blocks, and maintaining sites is given, as well as tidbits of other interesting information. Some of the photos show carefully constructed structures that will hold about 8 or 9 separate bee boxes. Others are created with boards or pallets, separated by bricks, and stuffed with a variety of material that will attract not only bees but other insects such as ladybeetles. The site is fun to peruse and is sure to generate a desire to emulate at least one of the structures. At the FWG we are already planning to create several and will be keeping an eye on them throughout the summer to see who uses them.

References:
***Attracting Native Pollinators. Protecting North America’s Bees and Butterflies. 2011. By the Xerces Society. Storey Publishing. I can’t say enough good things about this marvellous book. It provides excellent information, complete with photos, of different types of bee structures, good instructions for how and when to install, how to keep nest boxes and bundles clean, and much more. Buy it!!! It is the best source around; you need no others!

Bee and insect condos and hotels: inspirationgreen.com/insect-habitats.html

NAPPC Pollinator listserv: pollinator.org/nappc/listservrules.htm Provides a variety of topical and worthwhile information with much current information about bees and their conservation and efforts to protect them.

North American Pollinator Protection Campaign: pollinator.org/nappc/index.html The premier site for all things to do with conservation of pollinators.

Pollinator Partnership (NAPPC): pollinator.org/index.html Provides information about all pollinators, with an emphasis on bees.

Xerces Society: www.xerces.org/ One of the best all-round websites dedicated to bees and all pollinators, with a wealth of good, trustworthy information. Check under: www.xerces.org/fact-sheets/ for information on bee boxes.

More references for building bee boxes will be added when I find ones that are suitable.

Leafcutter Bees (Megachile sp.)

By Christine Hanrahan

Megachile constructing nest

As spring very slowly chugs its way into our region, many of us find our thoughts turning, longingly, to gardens and gardening. Those of us inclined to create and maintain gardens for wildlife, are also interested in the various things we can do to enhance our site for birds, bees, and other creatures. Bird boxes, bird baths, squirrel houses, roosting boxes, toad houses, and bee boxes are just some of the things that can be installed to help our fellow creatures. In this article, I’d like to focus on bees, and more specifically, on one type of bee that readily comes to bee boxes: the leafcutter bee in the genus Megachile.

First, a word about accommodation for bees. There are any number of plans for building bee boxes, ranging from the very simple to the extremely elaborate. In another article I’ll talk about the wealth of information available, but here I want to mention one very simple bee box we installed at the Fletcher Wildlife Garden a few years ago and how it attracted a number of Megachile leafcutter bees. Made for us by Bruce Burns, it was initially part of a display we had created to celebrate pollinators. In mid-summer 2009, I installed the bee box on a south-facing post behind the compost bin. A few days later I went back to see if anything might be using it (not really expecting any activity, but what did I know!). To my surprise, I found several leafcutter bees busily investigating the holes in the box. Within a couple of weeks it was very apparent that this bee box was being well used by a number of these bees, and I watched, fascinated, as they carried leaf sections, cut from rose bushes, into the boxes. When an AAFC scientist installed temporary bee boxes at the FWG in the summer of 2012, leafcutter bees were common inhabitants.

The family Megachilidae, typically called the leafcutter bees, includes a variety of genera, but the ones I am especially interested in are those in the genus Megachile. They are very common at the FWG, as indeed, they are throughout this region. Some years before I installed the bee box, while out exploring near Carleton Place, I’d come across nest sites containing a few leafy cells made by Megachile bees, and they were so remarkable that I began looking for similar cells in other areas. Most of the ones I found were under rocks, but they could equally be in rotting wood, in tunnels in the ground, in and around human made objects such as pipes, under bricks, or, as at FWG, in bee boxes.

The bees cut nearly perfect circles from leaves in the Rosaceae family, to construct tubular shaped cells, beautifully formed, and sealed with a leaf circle. In these cells a ball made of pollen and nectar is placed and an individual egg laid on top. A nest site can contain several cells, each closed off with a leaf circle. Some of the ones I have found were newly constructed, the leaves still fresh and green, others old and the leaves dried out. Some had obviously been disturbed by a predator. Some were half buried in the soil, others were jumbled together on top of the soil but under a rock.

I don’t know the exact species of Megachile that made these nests, but two common species are Megachile frigida and M. latimanus (the latter I have photographed at FWG, and the photos were identified to species by an expert). I tend to call all the Megachilid leafcutter bees I see, Megachile sp. These bees are easy to spot, as they carry pollen on their abdomens, instead of in pollen sacs on the legs, as most bees do.

Following are photos of the bees and their nests, including a bee busily constructing her nest. Many of these photos were taken at the FWG.

Overwintering Butterflies

by Christine Hanrahan

Winter may seem an odd time to be thinking of butterflies, but on your winter walk, you may actually be passing a butterfly or two, without knowing it. How can that be, you may ask? Well, our overwintering butterflies frequently find hibernation sites under loose bark of trees or in crevices, cavities, and even caves. I’ve also seen butterflies emerging in spring from the eaves of old buildings.

Many folk find it astonishing that butterflies, which we think of as fragile creatures, can survive our cold winters. Not all butterflies overwinter as adults, of course. In fact, only a few do so in this region, but they fascinate us because of their ability to withstand snow and freezing temperatures. Around Ottawa, Mourning Cloak (Nymphalis antiopa), Eastern Comma (Polygonia comma), Green Comma (Polygonia faunus), Question Mark (Polygonia interrogationis), Milbert’s Tortoiseshell (Nymphalis milberti), and Compton Tortoiseshell (Nymphalis vau-album) overwinter in their adult form. Other species overwinter as adults further south, the most familiar example being the Monarch butterfly which winters in Mexico.

How do these delicate butterflies survive the winter? In a word, diapause. As explained by James and Nunnallee (2011), hibernating adults are dormant “and in a physiological state called diapause, characterized by a lowered metabolic rate and radical biochemical changes. Diapause is different from simple dormancy or inactivity as occurs in butterflies and their immature stages during cool periods in spring and autumn or overnight. It is a rigidly controlled physiological mechanism that is genetically fixed or induced by environmental cues.”

Before hibernating, these adult butterflies fatten up by feeding voraciously, often on rotting fruit and sap. This is no different from what hibernating mammals do (think of bears gorging on food to put on fat for the long winter months).

Warming weather encourages butterflies to become active again, even for just a brief period. During the very early, warm spring of 2010, I found butterflies taking advantage of the warmth in mid-March. Likewise, during the unusual heatwave of mid-March, 2012, when the temperature hit +30, I saw several Mourning Cloaks fluttering around the woods. But when the temperatures cooled again, they vanished until the next warm spell.

The most common species that I see, almost without fail, as soon as we have a few warm days in early spring are Mourning Cloak, Eastern Comma, and Compton Tortoiseshell – sometimes all three in the same general vicinity when walking through woodland sites.

How do other local butterfly species spend the winter? Most do so in the larval (caterpillar) stage, but some overwinter as pupae and some, such as hairstreaks and the European Skipper (Thymelicus lineola) in the egg stage. Just as it seems amazing that adult butterflies can survive our frigid winters, it seems to me equally miraculous that larvae and pupae can withstand the rigours of cold weather.

Last winter (2011/2012), I kept two Black Swallowtail (Papilio polyxenes) in a glass aquarium in my garden shed. I didn’t believe that the seemingly desiccated looking pupae could really become butterflies, but they did. In late April, I brought the aquarium outside into the garden and, on 26 May, a female Black Swallowtail emerged, followed a week later by a male from the second pupa. Like overwintering adults, larvae and pupae also prepare for hibernation. “By changing their physiology, butterflies, or their eggs, larvae, or pupae, are able to survive the winter for months in a state of suspended animation.” (James and Nunnallee, 2011)

Next time you are on a winter walk through a woodland, remember that you may well be passing some overwintering adult butterflies, just waiting for those first warm days of spring to fly once more.

References: James, David G. And Nunnallee, David. 2011. Life histories of Cascadia Butterflies. Oregon State University Press.

Wiggle, waggle, woo: Hey, Bee, Vote for Me!

The recent American election once again highlighted that electoral politics in the United States are very different in structure than in Canada – electoral colleges, simultaneous elections of Congress and Senate, ballot initiatives and the fact that based on remit of powers, an American President has far less influence over his country than a Canadian Prime Minister (PoliSci 101 and a great digression from our topic at hand!)

However, did you know that HONEYBEES also have their own elections, complete with smear campaigns, speechifying and converting as many undecided voters into supporters as possible? This week’s PBS’ Nova Science Now showed how Honeybees decide on a new nesting site. The knowledge was presented as part of understanding how information is shared and how the human brain may function more like a hive mind in and of itself than previously thought. Continue reading

A bad day to wake up as a honeybee. . .

As if colony collapse disorder wasn’t misery enough, now the beleaguered honeybee has parasitic flies to deal with as recently reported in Washington State. The parasitic flies are native, but have never been known to target honeybees, a European import. Flies lay their eggs in the bees, which cause erratic behaviour including leaving the hive at night and being unable to fly back, resulting in death. The erratic movement has been referred to as ‘zombie-like’. Rather unfortunate with Halloween coming up. Hopefully, the issues can be solved on the west coast!

Watch a video here on the Weather Network.

**updated**

But Paul van Westendorp, provincial apiculturist at the BC Ministry of Agriculture, isn’t so sure that this is a new issue to be concerned about. He claims that the flies – scuttle flies, to be precise – lay their eggs in sick or dying bees which then leave the hive to prevent polluting the hive with their carcasses. At this time of year when food sources are more scarce, there is a concomitant increase in affected bees as they die off. So, the zombie bee is just a myth.

Christine’s FWG Walks: Late August

by Christine Hanrahan

Christine is one of FWG’s volunteer naturalists who writes in great detail about her visits to FWG. A great way to visit with us virtually and keep on top of what you might see when here in person!

Hi all,

There is always something interesting to see at the FWG, and today was no exception. While walking through the garden with a couple of visitors from England, we were astonished to see an American Bittern take off from just west of the old field, about 4 feet away from us. It had been standing in the midst of sow-thistles, and it landed in the middle of the buckwheat field.

While looking across the buckwheat field, before we saw the bittern, we could see at least 50 monarchs!! It was quite the sight, believe me. There were more in the BYG, and elsewhere. Continue reading

Mad about mothing – the OTHER winged beauty

by Diane Lepage // FWG Butterfly Meadow Coordinator

Macaria promiscuata – Promiscuous Angle Moth. Photo by Diane Lepage.

Moths are very interesting creatures that are worth paying attention to. My interest for those beautiful and sometimes oddly shaped moths started in my early adulthood, and increased when I got my first digital camera. It was originally the Silkworm moth family, such as the Luna moth,   my attention and made me pursue this hobby. For me, it became a serious interest and some would say a passion! With over 1500 species in Canada, I was sure to be busy for a long time looking for all those beautiful moths. Continue reading

Monarchs make the news

Monarch Butterfly on Common Milkweed, photo by David Hobden

Pollinators are numerous and varied, but a segment that for the media comprises predominately butterflies or bees. Monarch Butterflies are well-known as the poster child for pollinators, only recently having to fight it out with the cute and furry Bumblebee for facetime on pollinator topics. However, the plight of the Monarchs remains: as a migratory species dependent upon very specific plants to complete its lifecycle, this is a very vulnerable butterfly to climate change and land conversion.

The Toronto Star published an article this weekend on the plight of the Monarchs, and made mention of some initiatives to encourage people to create pollinator gardens. Fletcher’s own Monarch Waystation Project (and waystations in general) wasn’t covered, but we’re always happy to see how important Monarchs are to people across Canada. Apparently, Monarchs made it to Calgary which is a first in recorded history! The biggest issue of Monarchs reaching even further destinations is that they cannot find sufficient food sources or larval host plants. This is a greater issue in the Prairies where grazing lands preclude introducing Common Milkweed nearby as it is poisonous to livestock. Thus, urban centres will become some of the most important habitat areas for migrating Monarchs. Continue reading

Honeybees are on the rise but pollinator demand grows faster

Recent research shows that while populations of Honeybees are on the rise, the overall need for pollinators is rising faster. Good reasons to create pollinator habitat for our many native bees and pollinating insects near crops!

From Cell Press: The notion that a decline in pollinators may threaten the human food supply – producing a situation that has been referred to as a “pollination crisis” – can be considered a myth, at least where honey bees are concerned, say researchers reporting online on May 7th in Current Biology, a Cell Press publication. First of all, most agricultural crop production does not depend on pollinators. On top of that, while honey bees may be dwindling in some parts of the world, the number of domesticated bees world-wide is actually on the rise, their new report shows.

“The honey bee decline observed in the USA and in other European countries including Great Britain, which has been attributed in part to parasitic mites and more recently to colony collapse disorder, could be misguiding us to think that this is a global phenomenon,” said Marcelo Aizen of Universidad Nacional del Comahue in Argentina. “We found here that is not the case.”

By analyzing data from the Food and Agriculture Organization of the United Nations for temporal trends in the number of commercial bee hives, they found that the global stock of domesticated honey bees has increased by about 45 percent over the last five decades. That increase has primarily been driven by an increased demand for honey from a growing human population, rather than an increased need for pollinators, he added.

But the news isn’t all good: The data also show that the demand for crops that rely on insects for pollination has more than tripled over the last half century, suggesting that the global capacity for pollination may still be under considerable stress. These crops include “luxury” agriculture items, now common in any supermarket, like plums, raspberries, and cherries, as well as mangos, guavas, Brazil nuts, and cashew nuts.

“We were particularly astonished when we found that the fraction of agricultural production that depends on pollinators, which includes all of these luxury agriculture items, started growing at a faster pace since the fall of communism in the former USSR and Eastern Europe, and at a much higher rate than the larger fraction of agricultural production that does not depend on pollinators, including wheat and rice, which just follow human population growth,” Aizen said. “Although the primary cause of the accelerating increase of pollinator-dependent crops seems to be economic and political – not biological – their rapid expansion has the potential to trigger future pollination problems for both these crops and native species in neighboring areas.”

The associated increase in demand for agricultural land could also hasten the destruction of habitat that now supports hundreds or thousands of species of wild pollinators, which would in turn cause a drop in crop yield, he said.

“Most importantly, decreasing yield by these pollinator-dependent crops surely would imply rising market prices, which undoubtedly would constitute a further incentive for their cultivation,” Aizen said. “This situation would create a positive feedback circuit that could promote more habitat destruction and further deterioration of pollination services. The good news is that less-intensively managed agro-ecosystems that preserve patches of natural and semi-natural habitats and uncultivated field edges can sustain abundant and diverse communities of wild pollinators.”

 The researchers include Marcelo A. Aizen, Universidad Nacional del Comahue, Rio Negro, Argentina; and Lawrence D. Harder, of University of Calgary, Calgary, Alberta, Canada.

Contact: Cathleen Genova
cgenova@cell.com
617-397-2802
Cell Press

http://www.eurekalert.org/pub_releases/2009-05/cp-hba043009.php