I've had several questions recently about the Bambeco solitary bee house sold at Costco (they sell the Swiss Alps model), so I decided to head to my local store to check it out. While the price is amazing, the house has a few features that are not so ideal. For details on what makes a good solitary bee house, see here and here.
The depth. At 4.5 inches deep, it is sufficiently deep to allow the production of female and male bees.
What's not so good:
The nesting tube diameter. While the variety of diameters is good, solitary bees need tubes from 3/16 to 5/16 in diameter. While other arthropods, such as spiders, may use the larger tubes, they will not be used by bees.
Limited protected overhang. The nesting tubes should be placed so that the entrance has a bit of protection. That's why we make our houses at least an inch longer than the tubes.
The nesting tubes are glued in place. Once a tube is used it should be replaced to help prevent the build up of pathogens.
Update, March 2019
The bee house is not holding up well to the winter weather. Here's a photo showing some superficial mold as well as separation of the sides from the base. Note that I added extra protection by attached redwood fence boards to increase the cover of the roof.
My last post covered the use of color in garden design from the perspective of what bees see. While aesthetics are important in any garden, the needs of bees come first at the Haven and other bee gardens. Here are a few examples of color combinations that are attractive to us and provide both pollen and nectar for bees.
Shades of purple throughout the year
As was mentioned in my last post, purple is a color that bees see well. Here are some ideas for shades of purple throughout the year:
Winter: rosemary (nectar), germander (nectar), ceanothus (pollen and nectar), phacelia (pollen and nectar)
Spring:ceanothus (pollen and nectar)
Summer: sages (nectar), Russian sage (nectar), zinnia (pollen and nectar), cosmos (pollen and nectar)
Fall: aster (pollen and nectar), bluebeard (pollen and nectar)
Shades of yellow throughout the year
As a complementary color to purple, yellow is attractive against any of the plants listed above. Some yellow flower choices include:
Winter:bidens (pollen and nectar), blanketflower (pollen and nectar)
Spring:bidens (pollen and nectar), blanketflower (pollen and nectar), lupine (pollen and nectar)
Summer: sage (nectar), sunflower (pollen and nectar)
Fall: sunflower (pollen and nectar)
Spring: Santa Barbara daisy(pollen and nectar), buckbrush (pollen and nectar)
Summer: Santa Barbara daisy (pollen and nectar), gaura (pollen), veronica (pollen), coneflower (pollen and nectar), zinnia (pollen and nectar), cosmos (pollen and nectar), California buckwheat (pollen and nectar)
Fall:gaura (pollen), California buckwheat (pollen and nectar)
Hot colors throughout the year
Winter: California poppy (pollen), Cape balsam (pollen and nectar)
Spring: Cape balsam (pollen and nectar), sage (nectar)
Summer: Cape balsam (pollen and nectar), coneflower (pollen and nectar)
Fall: Cape balsam (pollen and nectar), sage (nectar), sedum (pollen and nectar)
Spring is here, and planting is underway in bee gardens throughout California. And planting, especially if you're creating a new garden, means you are thinking about design. In this series of posts I will cover various aspects of garden design -- such as color, texture, shape, and size -- from the perspective of what bees need. Based on research, this information should provide a solid foundation for a successful bee garden.
This post will focus on color. An understanding of color theory is helpful in creating an aesthetically pleasing garden for us, but color is also relevant for bees. All color wheel screen shots shown here are from the Adobe web page.
1. Complementary colors. Colors opposite each other on the color wheel are complementary; this is one of the easiest ways to select colors. Using opposite colors together makes each color appear more vibrant.
2. Analogous colors. Colors adjacent to each other on the color wheel are analogous; using these colors can be a bit trickier, especially with hot colors like oranges and reds. One way to combine these effectively is to mix in white, as is done here with white gaura in this planting of the analogous colors pink (echinacea) and purple (tall verbena).
3. Shades of one color. This is the easiest combination to pull off. Cool colors (blues and purples) tend to create a calming effect and make the garden appear larger, while warm colors (reds and yellows) create energy and make the garden appear smaller. Here is an example of shades of a cool color (purple) used in the Haven:
So how do we meld this with bee biology? Here are some pointers:
1. Bees see color differently than we do. They don't see red at all, and see purple very well....there's a reason we have so many purple flowers in the Haven. Here's an example: the first photo shows a flannel bush flower in daylight, while the second shows it under ultraviolet (UV) light, which is the light spectrum where bees see. The 'invisible' nectar (to us) is a bright blue beacon to bees under UV light.
But, you might be thinking, I see bees on red flowers all the time! Well bees can use more than color to find a flower, which brings us to scent....I'll discuss this in a future post.
2. Does color pattern in the garden matter to bees? One study (Proc. R. Soc. London B. 2003. 270: 569-575) found that honey bee foraging distance was longer in simple landscapes; this makes sense because honey bees do best with a varied diet and need to travel further to find a mix of flowers in a simple landscape. Conversely, waggle dance activity was greater in complex landscapes because the patches of plants were more variable -- high quality and low quality plants were mixed together. So it's also important to ensure a good mix of high-quality bee plants in appropriately-sized patches.
3. Another aspect of flower color often not considered is patterns on the flowers themselves. Called nectar guides, these serve to guide bees into the nectary. Of course they pick up and deposit pollen as they do this, thereby pollinating the flower.
For lots more detail about how bees see, check out this article. My next post will cover shape, size, scent, and texture. I'll finish with suggested plant lists and planting plans. Here's to your successful bee garden!
We have an exciting selection of classes and events planned for 2018 at the Haven. And we're off to a great start: 575 visitors joined us on Biodiversity Museum Day to learn about bees and flowers, to make 'Feed the Bees' cookies, and to try their skill at safely catching and observing bees with our insect vacuums. The day before #BioDivDay we hosted the Outstanding Farmers of America. It was great to share the Haven with so many of the growers who depend on bees to produce their crops.
We'll be offering our bee gardening class again this year; a new class is Bee Watching for Beginners. Ever wondered what all those different bees at the Haven or in your garden are? This is the class for you!
Our next event is our Spring Open House on April 7; click here for a complete list of 2018 events and classes. Hope to see you there!
Like all animals, bees need food, water, and shelter. Most insects get all the water they need from their food: think of a caterpillar that feeds on plant leaves, which are mostly water. However, the pollen and nectar that constitute a bee's diet don't contain much moisture, so bees must have a water source. As the weather warms and foraging activity picks up, honey bees will start looking for water as well as pollen and nectar.
Honey bees are good learners, and once they find a water supply they will return regularly. Water is so important that foragers will do the waggle dance to direct hive mates to water sources just as they will for flowers. So to direct bees to the water you want them to use, it's important to provide attractive sources early in the year (i.e. now!) so they will learn these rather than the places you don't want them, such as a swimming pool.
So just what is a good water source? Here are some guidelines:
Accessible to bees
Bees can't swim! They must be able to stand where it's dry and drink. Good systems include shallow bird baths or pot bottoms filled with water and pebbles or corks. These allow the bees to stand and drink; they'll generally dry out too quickly for mosquitoes to be an issue. If your water source is a pond, Bacillus thuringiensis israelensis may be used for mosquito control as it's harmless to bees. At the Haven, we create 'pots' using coiled soaker hoses. Connected to a timer-controlled water supply, these are a great way to efficiently deliver water in bee-sized droplets. I provided construction details for this in a previous post.
Nutritious for bees
Water needs to be nutritious? Surely bees need the same fresh, clean water that you or I might want? It turns out that water is an important route for bees to obtain essential nutrients. Butler (J. Experimental Biology, 1940, (17):253-261) coined the term 'dirty water' to refer to water containing nutrients. Probably because in the agricultural areas of Great Britain where he observed bees, they frequented areas we might consider undesirable. As he stated in his paper,
"It is well known that honeybees tend to collect water from many undesirable sources, such as rain-water gutters that are choked with decaying organic matter, on the puddles that form on the top of cow dung and sewage effluent, rather than from a source of clean water provided in the apiary for their use."
He performed chemical analysis of the water at these sites and found it to be high in various nutrients that were leaching from the organic material. Water with high sodium chloride (yes, table salt) seemed to be the source preferred by bees. A previous study (Hertz, Z. Vergl. Physiol., 1935, (21):463) suggested that bees used olfactory cues to located these preferred sources. To test this, Butler washed preferred water using activated charcoal and found that bees were unable to distinguish between the washed preferred water and distilled water. This confirmed Hertz' theory that odor cues are used to locate mineral-rich water. The take home from this? Don't place your water source near highly scented plants, and let leaves and algae sit in your bee water source.
More recent work by Bonoan et al. (Ecol. Entomol., 2017, (42):195-201) looked at drinking water as a source of micronutrients for bees. Honey bees were allowed to forage freely in a meadow and were provided water sources with varying chemical components. As with Butler, during much of the year they found that bees had a strong preference for sodium-rich water, regardless of plant diet. In the fall, however, when pollen is scarce, they showed a preference for water sources containing calcium, magnesium, and potassium, all of which are found in pollen. This demonstrated that honey bees have the ability to switch water sources to compensate for dietary nutrient deficiencies.
Plants as water sources
I mentioned earlier that the plant products consumed by bees -- pollen and nectar -- aren't good sources of water. Plants can be an indirect source, though. In a garden with overhead irrigation or large amounts of dew, water can sit for several hours on leaves that are covered with dense hairs. I've shown two examples from the Haven below. Since overhead watering can promote disease and waste water, try giving plants like these a quick wash from the hose so they'll do double duty as nectar and water sources.