Neonicotinoids: euphoria then death for bees

Two papers published in the journal Nature earlier this week are causing quite a stir in the bee world. The first, “Seed coating with a neonicotinoid insecticide negatively affects wild bees” by Rundlof et al. is unique in that the authors were able to perform controlled field experiments. This is often difficult to do because neonicotinoids are so prevalent in the environment that finding “clean” fields is tough.

But these scientists, working in Sweden, were able to obtain sixteen test plots of oilseed rape (canola). In eight of the plots, the canola seeds were treated with a combination of Clothianidin and a non-systemic pyrethroid. The other eight fields were planted without the insecticide treatment.

Not surprisingly, the wild bees in the treated fields were severely affected by the insecticides. What amazed the researchers was the amount of disruption. They found reduced wild bee density, reduced solitary bee nesting, reduced bumble bee colony growth, and reduced bumble bee reproduction. According to lead author Maj Rundlof, less than half as many wild bees were found in the treated fields, and colonies of bumble bees failed to increase in weight. Oddly, the honey bee colonies in the test appeared normal.

In the second study, “Bees prefer foods containing neonicotinoid pesticides” by Sébastien C. Kessler et al, researchers found that bumble bees and honey bees were unable to taste neonicotinoids but consistently chose syrup containing neonicotinoids over syrup that didn’t. Why? Some scientists believe that the effect of eating neonicotinoids may produce a euphoria in the bee similar to the effect of nicotine in humans.

So, given a choice of flowers—some with the insecticide and some without—bees may prefer the treated flowers because they get a high, even though that choice increases their overall exposure to the toxic chemicals and may cause impairment and death. Sound familiar?

In my opinion, these papers confirm what we bee-lovers have always suspected, which is that wild bees will be far more affected by field-applied pesticides than managed honey bees. Managed honey bees, after all, can be moved out of a field at the close of pollination season, whereas the wild bees cannot leave.

When compared to honey bees, most wild species:

  • Are active (and reproduce) during a short season, not much longer than the flowering time of a crop like oilseed rape
  • Fly only short distances and so are limited in their food choices
  • Live in the soil where the contaminants remain active for long periods
  • Have small populations sizes so the loss of a few individuals is significant

How important are these wild bees? How much pollination do they actually do? The answer, I think, is that we don’t really know. But having studied wild bees in graduate school, having spent years watching them, photographing them, and learning to identify them, I believe we underestimate their importance. I also think honey bees get a lot of credit for the work done by wild bees.

Determining their value is difficult because of their size. When we think of wild bees, we tend to think of the monsters: orchard mason bees, bumble bees, carpenter bees, even some of the diggers and miners. But many of the wild bees are so small that most people would never notice them. Some the size of fruit flies look like tiny splinters on a flower or a speck of dirt. Because they are so small and fast, it is hard to see what they are doing. It’s even hard to do controlled studies because they are difficult to screen out of a field or test plot.

But work? These little ones work themselves silly giving us flowers and trees, herbs, seeds, crops, medicinal plants and more.

If we studied only those living things that are easy to see—eliminating molds, viruses, bacteria, and single-celled plants and animal—we wouldn’t have a very good idea of how the world works. Similarly, if we study only the bees that are easy to see, we get a skewed view of how pollination works.

For example, I think a little sweat bee, Halictus rubicundus, may be one of North America’s premier pollinators. Found in all 50 states and most provinces, it seems to be everywhere, but no one has even bothered to give it a common name. When you walk through a field, they scatter like tiny flies, but work side-by-side with the recognized pollinators like honey bees and bumble bees.

Only after we eliminate them—along with the many other silent pollinators—will we know how valuable they were. When that happens, we will be sorry. We will wonder what was ever going on inside our maximum-crop-yield, perfect-produce, chemical-industry-protecting little brains. Of this, I am sure.


Halictus rubicundus are working hard all around us. This is a male on a chocolate mint. © Rusty Burlew.

How to build a slatted rack

I never go without a slatted rack in my beehives, and I extoll the virtues of them every chance I get. David Manning, a beekeeper in Missouri, makes some seriously good-looking slatted racks that you can see in the photos below. For those of you who are handy in the woodshop, David has graciously shared his method in the following write-up.

Thank you, David, for taking the time to share with us.

Materials List

(2) ¾” x 2¼”x 19⅛” for side boards
(2) ¾” x 2¼” x 16¾” for front and back board
(1) ¾” x 4¼”x 15¼” for shelf at front of rack
(10) ¾” x ¾” x 14” slats

Cutting dados on pieces

  1. On the ends of both 2¼” boards cut a dado ⅜” x ¾”. These front and back boards will be nailed to the end of the side boards making the side dimension a full 19⅞”.
  2. On the two front and back pieces cut a dado ¼” from the top of the 2¼” board. The dado needs to be ¾” wide by ¼” deep.
  3. On one of the 15¼” sides of the shelf board cut a ⅜” dado ½” deep the full length of the board, making sure that you have 3/16” on each side of the dado. One end of the slats will fit in this dado.
  4. On the two side boards where the shelf will set in a dado, a ¼” x ¾” dado will need to be cut ¼” from the top of the board the width of the shelf board – 4.0 inches. There are two ways of accomplishing this, dado past the 4 inch so that you have a 4 inch x ¼” dado cut with the curved cut beyond the cut. The second way is to cut the dado 4 inch long and using a chisel, remove the part of the dado that needs to be cleaned out in order to have a full 4 inches.
  5. On one end of the ¾” x ¾” x 14” slats, set up a dado blade to cut a 3/16” wide x ½” deep area from opposite sides of the same end of the slat. This should leave a joint on the end of the slat that has a centered ⅜” x ½” area. This is the end that will fit in the ⅜” x ½ “deep dado on the shelf board. The other end of the slat stays ¾” x ¾” and fits in the ¾” dado in the back 2¼” board.

Spacing of the slats in the frame

The purpose of this slatted rack is to have the 10 slats line up with the bottom of each frame in the brood super. To achieve this, the two end slats, #1 and #10, those closest to the sides, need to be spaced so that there is a 5/16” space between the slats and the side board. The remaining 8 slats will have an 11/16” space between each of them.

Securing the slats to the shelf board and the back board

  1. Using Titebond III Waterproof wood glue put glue on edges of boards that will come in contact with another board. In other words, any where there is a dado.
  2. Using 5/8” brads or brad nailer with 5/8” brads or staples, place the brad 5/16” from the edge of the shelf board where the slats mate with the board.
  3. On the outside of the back board draw a line 5/8” line all the way across the length of the back. Place a 1½” brad on the line and centered on a slat that has been correctly spaced.

If your brads are countersunk, on the outside of the frame, fill with wood putty, sand, and then put several coats of sanding sealer on the outside of the assembly that will be exposed to the weather and on the top and bottom edge of the outside frame.

Apply primer and several coats of good exterior paint. I use an exterior paint that the primer and paint are combined.

David Manning
Sparta, Missouri

For more on slatted racks, see:

How to use a slatted rack

Slatted racks: how should the slats be arranged?

Hive five: the best ventilation equipment


The top of the slatted rack is the shallow side. © David Manning.
The bottom side of the slatted rack is the deep side. © David Manning.
The end of the slatted rack with the crosswise shelf goes on the front of the hive, above the entrance. © David Manning.
A complete hive with the slatted rack in place. © David Manning.
The bees are happy with it. © David Manning.


Photos of Autumn Joy sedum

Here are some nice photos of Autumn Joy sedum with honey bees attached. It seems like everyone knew about this plant except me, so I’m happy to catch up. Beekeeper Marc Balboa, who made the photos, says:

My bees are crazy over them. Native bees too, although I’m not sure which. Bumble bees for sure, some very large bees with yellow backs with a large black spot in the center, and lots of smaller dark bees. . . . Regarding propagation, it could not be easier. Break off any branch, and you will because they’re somewhat brittle, stick it anywhere else, and it will thrive. I started with four. I now have nearly twenty.

I’m always looking for a bee magnet so I can get pictures of natives, so I’m looking forward to this. By the way, those big bees with yellow backs that Marc mentioned sound like carpenter bees. We’ll have to wait and see.


Honey bee on Autumn Joy. © Marc Balboa.
I love the colors in this garden. It looks more like spring than fall. © Marc Balboa.
Autumn Joy looking like honey bee heaven. © Marc Balboa.
A pair of honey bees on Autumn Joy sedum. © Marc Balboa.


Snack food for bees: Autumn Joy sedum

Right now I’m totally fixated on Autumn Joy sedum as a honey bee plant. It began when I was typing the responses to the Honey Bee Suite plant survey. The same plant repeatedly cropped up in the responses, and it was unusual in that people were always very specific about the variety: it couldn’t be just any sedum, it had to be Autumn Joy.

Immediately afterward, I tried to buy seed but I couldn’t find any. Added to that, I read that it was difficult to start from seed. Since I had no prior experience with sedums, I decided to heed the advice.

As soon as perennials began to show up in the local stores, I began to search. My first several attempts yielded nothing, but finally I went to the huge local gardening center that seems to grow faster than the plants they sell. It must be four or five times bigger than it was just a few years ago; in fact, it now fills multiple buildings. They even have a display of hives and smokers, conveniently located near the check-out for those customers who, while standing in line, develop a sudden urge to keep bees.

Now bear in mind that I didn’t know what I was looking for, only that is was called Autumn Joy sedum. But by strolling up and down the aisles with a cart, I eventually found myself in the sedums.

Actually, “strolling” isn’t the best word. Every time I came to a hose—and there were plenty—I had to pick up the front end of the cart and then the back end. I tried running over the the first hose really fast but nearly catapulted myself over the top. And for some reason I can’t remember, I had to lift the cart from the bottom. At any rate, the strolling, bending, and lifting weren’t so bad until I put a few two-gallon potted bushes in there, and then it became a kind of weight-bearing exercise that wasn’t any fun.

In the sedum section I was dumbstruck by all the different varieties. They were arranged on tiered shelves starting at ground level, but there was only a few of each of maybe 60 or 70 named cultivars. Methodically I slid along on my knees reading all the little tags that were partially stuck in the dirt, pulling them out one by one, but no Autumn Joy. When I found nothing, I went back through the tags again, certain I must have missed it. But no.

Finally, with filthy knees and gritty hands, I asked an employee with a hose where the Autumn Joy was. She more or less sneered and said, “We don’t sell candy bars.”

I didn’t pursue it. At any rate, there were other plants on my list. I found an Eryngium, some Agastache, two Ceanothus, and a Russian sage. The show rooms were filled with the intoxicating aroma of damp earth and wet leaves. The hoses hissed at the junctions, and little arcs of spray painted the walkways and dotted my clothes with mist. At one point the aroma of sage was so heavy I could taste it.

Finally, I headed toward the cashier, having selected more plants than necessary. The very last time I bent down to lift the cart, I saw it: a little hand-written card announced, “Autumn Joy Sedum.” These plants had big leaves (I’d spent all that time looking at little leaves) and, of course, these plants weren’t anywhere near the others. In fact, they were in a different building altogether. Not about to let them get away, I put all six in my cart.

So now I am mother to a half-dozen “Almond Joy” plants—candy bars for bees. From what I’ve heard, honey bees trip over themselves to get to these. I don’t know about native bees, but I intend to find out. I even began a new Pinterest board dedicated to learning as much about these as I can.

So far I learned they are easy to propagate, fairly winter hardy, and bloom in the fall when other forage is short. They provide fall color, winter bird food, and they are totally non-invasive. Thank you to all who recommended them.


Autumn Joy sedum. Photo by Leonora Enking.
Autumn joy sedum. Photo by Leonora Enking.

A beekeeping mystery

About ten days ago, on a cold and gusty mid-April day, I was making the rounds of my hives. All the colonies were tucked in against the 40-degree mid-morning sunshine. All but one.

Inexplicably, one hive had a group of about 200 bees frantically fanning at the opening. Other bees were nearby clutching blades of grass and fanning, and still others were fanning from their perches on the legs of the hive stand. Every bee was was facing the hive and beating its wings at a frenetic pace.

I’ve seen similar behavior when young queens are out on a mating flight. Some workers fly out with the queen, and others fan the entrance, making sure she know how to get back home.

The problem with this theory is that it was cold, windy, and early in the year. As a matter of fact, I hadn’t seen a single drone in 2015. So it didn’t seem like a mating kind of day.

It was too cold to dig through the hive and, at any rate, I didn’t want to disturb whatever operation they had going. Nevertheless, I did remove the lid for a peek. As soon as I opened it I heard the unmistakable sound of queen piping and chirping—as noisy as broody hens all scrambling for the same nest. I quickly replaced the lid, perplexed.

The colony isn’t large but about normal for having just overwintered. The queen is an unknown. Although she is marked, this colony was a mid-summer swarm that nested in a trap last year.

Due to temperatures and my own schedule, I haven’t yet been able to examine the colony, but from the outside all seems normal again. Nothing about it looks swarmy, so I imagine it must have been a supersedure in progress.

But will a colony send a virgin out on a cold and blustery day without a drone in sight? Do scout bees survey the local DCAs (drone congregation areas) before the virgin goes out, or do they just hope for the best? I don’t know the answers to these questions, but from my point of view it doesn’t look good. Any thoughts?