Texas Bee Watchers

Travis County Squash/Pumpkin Gardeners: Bee alert!

 

(photo by Dr. Jack Neff)

Do you still have Squash and/or Pumpkins blooming in your vegetable garden? A local bee researcher is looking for gardens (preferably with a lot of squash flowers) in which to look for the cute squash bee (Peponapsis pruinosa).

According to our local native bee expert, Dr. Jack Neff,  this squash bee presumably was native to Texas and the SE but may have expanded its range greatly in the NE with the spread of cultivation of squash and pumpkins by Native Americans.  A researcher is looking to see what, if anything, DNA has to say about  that expansion. Dr. Neff is helping to find examples of the bees in Travis County and would like to come see what you have flying in your garden.

The photo above is of a female P. pruinosa in a squash flower.  Dr. Neff says this is the most common view of a female, head in and going for nectar. Males, with their longer antennae, when not zipping between flowers, often perch on the anther column and face outwards. Wonder what they're looking for? Mmmm . . . 

 If you have had squash mature in your garden this year, you've probably had these native bees doing the work of pollination. So, if you have the flowers, you probably have the bees.

 So, Beewatchers, I know it's hot today, but science needs you! Today. Get out there. Watch for cute Peponasis (they're kind of big and easy to see). If you think you've got 'em, send an email to me (Kim)  at beewatchers@mac.com and I'll forward it on to Dr. Neff. Hurry! Researchers are depending on YOU.

 

Reposting: Bluebonnet Spots and Bees

I've never reposted a previous post before, but a recent discussion elsewhere on the web combined with the beginning of Bluebonnet blooming season here in Texas prompted me to repost this entry I wrote last year on the reasons why bluebonnets have flowers with white spots and flowers with purple spots.  It's really quite an interesting story.  Enjoy. Just click on the link to be redirected to the original post.

Bluebonnet Spots and Bees

Is a Cow Killer a bee, a wasp, or an ant?

I spoke to a wonderful group of people at the meeting of the Williamson County Native Plant Society last Thursday. I always learn a lot at these presentations from the questions people ask.

One question concerned wingless hymenopterans (bees, wasps, and ants). The question, in particular, concerned evolutionary aspects of Cow Killers. As commonly occurs, I had no idea.  So I’ve spent some time learning about Cow Killers in the last few days.

 So, why ask about them at a native bee talk?  Easy. 

 Turns out the females are parasitoid Wasps without wings who chew their way through the nests of ground-nesting solitary bees and bumble bees and lay their eggs in bee pupa growing in the nests. When the eggs of the Cow Killer wasps hatch, they eat the bee pupa. Yum.

Let’s get some of the biology facts down. First, Cow Killers are members of the Hymenoptera, but they are definitely NOT bees. They are not ants, either. They are actually predatory Wasps in the Mutillidae family.  Cow Killers (also known as Velvet Ants) are known by their scientific name, Dasymutilla occidentalis. There are other species of Dasymutilla found in Texas too. According to Texas A&M University Extension, Texas is also home to the Thistledown (or Gray Velvet) Ant. These little predatory wasps really do look like solitary bees!

The female Cow Killer doesn’t have wings (further adding to the identification confusion), but the male does. The female also has a very long stinger which she uses like a “multi-purpose stun-gun/venom injection apparatus” according to Dr. Eric Grissell in his indespensible book, Bees, Wasps and Ants: The Indespensable Role of Hymenoptera in Gardens. The male doesn’t have a stinger. The general scientific opinion seems to be that the sting of a Cow Killer is really bad–but probably not bad enough to bring down a cow!

I found a nice little article (here) that will give you a bit more detail on Cow Killers (Velvet Ants).

And here's a video from Youtube that shows a Velvet Ant (Cow Killer) searching for native bee nests on the ground.  The video also gives a nice talk about Cow Killers.

Watch out for these little girls when you are out in the wilds. This is one lady you do not want to pick up!

 

Do you get stung by bees?

I get asked this every time I give a talk.  The answer is no.  I was stung by honeybees several times when I was a kid, however.  I grew up with a yard of St. Augustine grass interspersed with clover. The clover produced "stickers" for seeds and cute flowers that attracted honeybees. And all the kids in my neighborhood went barefoot during the summer. A recipe for semi-disaster–at least in terms of stickers, stings, and screaming kids---but we lived to tell about it. 

That's a big bumblebee!

Recently, I've received several emails asking about stings.  I've found a  couple of websites about stings which you will find fun and interesting. 

Getting stung may hurt. OK, it may hurt a lot. But just how much?  Thanks to Justin Schmidt, developer of the Schmidt Sting Pain Index, you can learn just how much that yellow jacket sting (like spilling a beaker of hydrochloric acid on a paper cut) or honeybee sting (like a matchhead that flips off and burns on your skin)  is going to hurt. Check it out below.

Schmidt Sting Pain Index

And if you'd like to understand why some people can stand a lot more pain than others (all women, IMHO), check out the following article which explains why:

Your Genes May Make You More Pain Sensitive to Stings

Remember:  Don't mess with any hive you see. It could be a honeybee hive, but it could also be a wasp or hornet nest. These little animals are going to defend their hive from you and sting you. Solitary bees are much less likely to sting you, but if you try to catch a Carpenter bee or a Bumblebee with your bare hands, well, you might just deserve that wake-up call!

 

 

A Very Handy Manual for Bee Watchers

Drawing above from the Very Handy Bee Manual

I just added a link to the Very Handy Bee Manual: How to Catch and Identify Bees and Manage a Collection (VHM) to the Navigation Pages (click on Bees in the Navigation Bar). This handy little manual explains various collecting techniques for those of you who would like to get a closer look at the native bees on your flowering plants. It also covers making a collection, pinning bees, and many other techniques useful for folks beginning to make a serious study of native bees.

Even if you are not interested in collecting some of your own native bees, you may find the VHM an interesting read to see how graduate students and field biologists collect bees.

The VHM will be available on the Bees page even after this post falls to the bottom of your page.

How did the Bumblebee know which flower to look for?

 Photo by the great bumblebee photographer, Al Janelle.

Bumblebees live in colonies. Often, they nest in old rodent holes in the ground. From these nests, the bumblebees will head out over the landscape looking for nectar- and pollen-producing flowers. So once a bumblebee finds a good patch of flowers (maybe it's in your Official Certified Texas Bee-Friendly Garden?), how does the bumblebee let her sisters back in the colony know which flowers or patch of flowers is the most rewarding on that day? 

Could it be just hit or miss? Do Bumblebees just fly around looking and hoping to find a good patch?  That doesn't seem likely.  It certainly isn't very efficient. 

Well, back in 2008, a group of scientists from Queen Mary College at the University of London in the United Kingdom decided to find out.

Here's what they knew:  

1. Bumblebees can provide information about flower odors to their nest-mates.

2. Bumblebees produce an pheromone (a pheromone is a chemical capable of acting outside the body of the secreting individual to affect the behavior of another individual) when they return to the nest. This pheromone can cause the bumbleebees in the nest to leave the nest and search for food.

3. If an odor of a flower is present in the nest, it may cause the bumblebees to prefer that odor when they are out foraging.

4. Scientists did not know how floral scent was spread to the other bumblebees in the colony: through the air or through the honeypots (where the bumblebees store concentrated nectar).

So they proposed an experiment.  They took 136 bumbleebees and trained them to land on artificial flowers (blue squares of paper) with a puddle of sucrose (nectar) in the middle. How cool is that? Then they changed the Sucrose to either an Anise-flavor or a Peppermint-flavor. 

I bet you didn't know that the bumbleebees–at least British bumblebees– naturally prefer peppermint scent to anise scent. Anise is sort of like licorice–a scent I'm not particularly fond of either (not that that matters at all!)

Then the experiment began. They devised five different ways (treatments) for the anise-scent to get in the colony (and two controls).

1. in the air

2. in the air with the pheromone present

3. in a honeypot

4. in the honeypot with the pheromone present

5. the anise scent could be brought back by another bumblebee–who naturally releases the pheromone on its own

6. a control (no anise-scent)

7. the control with the pheromone

After being subjected to one of the seven different treatments above, bumblebees were given a chance to fly to or land on either an anise-scented artificial flower or a peppermint-scented artificial flower. 

Guess what happened?  The bumblebees who were exposed to the anise-scent by another bumblebee (treatment 5 above) found the anise-scented artificial flowers more often than the bumblebees receiving any of the other treatments. The bumblebees in the control groups (treatments 6 and 7) preferred the anise-scented artificial flowers much less so. So, no surprise here, really. The bumbleebees prefer to get their directions the old-fashioned way–from another bumblebee.

But, remember, the scientists were trying to figure out just how the bumblebees learned which flowers (in this case, anise-scented) were more rewarding. It surprised me that their results indicated that the pheromone really did not contribute to helping the bumblebees learn to recognize the anise scent. 

The scientists knew the pheromone had little effect because the number of approaches and landings was the same whether or not the pheromone was present. For example, as many bumblebees landed on an anise-scented artificial flower from treatment 1 as landed on an anise-scented flower from treatment 2. The addition of the pheromone showed no increase–and no effect. 

But, having the scent in the air or in the food (the honeypot) did. And having the scent on the bumblebee returning to the nest also had an effect.

So why did more bumblebees look for the anise-scented artificial flowers when the scent was brought to them by another bumblebee? The researchers thought maybe it was because bumblebees prefer the freshest scent of flowers and they could recognize it when another bumblebee enters the nest, flies around, and distributes the newest scent (in this case, anise) around the air of the nest, letting her nest-mates know that she's found some great flowers. In any case, the scientists were able to determine that the pheromone had nothing to do with letting the other bumblebees recognize the anise scent.

If you want to read the paper the scientists from Queen Mary wrote about their experiment, just click on Learning Flower Odors in a Bumblebee Nest. It might explain any questions you may have thought of when you were reading this post. 

It's a bit like when I bake a loaf of banana bread and leave the window open. My son will enter the kitchen, recognize the scent, and look all over for the loaf (counter?, refrigerator?, oven?). He knows the scent of my banana bread. Give him a taste of it and he'll look for more, too. I have no idea what he'd do if I flew around the kitchen waving a fresh loaf under his nose–but I can guess.

Strange Coincidences with Bee Nests and Basket Maker

Oh, my.  This large photo shows one of the first photos of the nest of a rare solitary bee.  It's made of flower petals!  

Dr. Jerry Rozen, a real official bee expert with the American Museum of Natural History, along with a bunch of other bee watchers, found this petal nest in Turkey while another group of bee watchers found the same nest in Iran. On the same day! What are the chances of that happening?

But, that's not the only interesting thing.  Last summer I attended a workshop on basketry with Jutta Frankie, wonderful wife of Dr. Gordon Frankie, another official bee expert from California. To the right is a photo of the beautiful basket she made that day–months before the photo of the solitary bee petal nest found by Dr. Rozen was published. It bears an uncanny similarity to the actual solitary bee nest, doesn't it?

Is there some amazing solitary bee channeling going on here? Does Jutta Frankie know more than she's letting on about solitary bee nests? 

Perhaps we should get some official bee experts to attend the next Basketry workshop? 

Or perhaps, I'm just spending too much time in the Texas heat at the Bee Garden.

 

Bee-Friendly Planting Guides for Texas

The Pollinator Partnership's mission is to protect pollinators, including native bees. One of the helpful things they have done is to publish Ecoregional Planting Guides. If you are getting ready to plant a Bee-Friendly Garden, you can use these guides to get started.

By clicking on the Ecoregional Planting Guide, you can enter your Texas zip code to determine which Ecoregion you live in. Seven different guides cover parts of Texas:

the Southwest Plateau and Dry Plains Steppes, 

the Prairie Parkland (Subtropical), 

the Great Plains Steppe and Shrub Province, 

the Southeastern Mixed Forest, 

the Outer Coastal Plain Mixed Province, 

the Chihuahuan Desert Province, and the

Arizona-New Mexico Province.

The Pollinator Partnership used names for regions of Texas based on R. G. Bailey's Classification System. His classification system for climate and vegetative regions of the US was first developed for the US Forest Service in 1978.

If you like looking at maps and want to see Texas broken down to even smaller subregions, you can take a look at The Ecoregions of Texas map. Looking at this map will certainly convince you that Texas is a big state with a lot of different climate/vegetation regions.

Plant some bee-friendly plants and you can watch bees right in your own garden every day.

Two Very Different Books on Bees

If you are a beginning Bee Watcher interested in learning more about bees, I recommend Bees of the World by Christopher O'Toole and Anthony Raw. The authors cover all types of bees (miners, masons, leaf-cutters, carpenters, etc.) as well as discuss social and solitary behaviors, the relationship between pollination and bees, bee biology, etc.  I think this is a good introductory book for all Bee Watchers–even though some editions have a photo of a FLY on the front cover.

Don't confuse the O'Toole book with The Bees of the World by Charles D. Michener. Michener's book is the standard reference work for bee scientists and very interested Bee Watchers. It covers bee biology, bee morphology, bee taxonomy, and contains keys for identifying bees to genera. 

However, it is not a book for the casual Bee Watcher.  It has only a few photos of bees. Use of the keys requires an understanding and familiarity of bee body parts and terms. You need to catch and kill a bee to use the keys. And a good microscope is certainly required for identifications. 

My first exposure to The Bees of the World by Charles D. Michener was in the Reference section of the Austin Public Library. For this book, I would suggest that you start at your local library as well. It's a great book, but it is technical, a bit intimidating, and costly. 

Field guides with photos for regular Bee Watchers are on their way soon, but, until then, one of these books might be able to provide you with good, solid information on bees. 

Bluebonnet Spots and Bees

 

The flowers of the bluebonnet are visited by several different native bees. I went through The Hymenoptera in America North of Mexico and searched for Texas bees that visited Lupinus and compiled a pretty long list. As the bluebonnets begin their annual bloom, I’ll be on the lookout for these genera of bees (and others, of course).

 

Hylaeus

Andrena

Anthidium

Hoplitis

Osmia

Megachile

Chalicodoma

Melissoides

Anthophora

Centris

Ceratina

Xylocopa

Apis

Bombus

 

I find it helpful to look at photos of these genera before I go bee watching on bluebonnets. Of course, there’s a lot of variation, but it does help me recognize common characteristics.

 

The Bluebonnet is an interesting plant. If you look at the photo above, you will see a white or pale yellow spot on some flowers and a purple spot on other flowers. Ever wondered why there were different spots on one plant?  Me, too. 

 

Apparently, all the flowers start out with a white or pale yellow spot. By the fifth day after the flower opens, the spot begins to turn pinkish and by the sixth day, the spot is completely purple.

 

Bees will choose flowers based on the color of the spot. In one study, 96% of bee visits were to white-spotted flowers. It appears that bees will limit their visits almost exclusively to white-spotted flowers. Wonder why?

 

Pollen from new white-spotted flowers is sticky and makes a nice ball. As the pollen ages, it is less sticky and gets powdery–and the flower spot begins to darken. It turns out that the color of the spot is a pretty good indicator for the bees. Scientists (Schaal and Leverich 1980) determined that a bee can gather much more pollen from white-spotted flowers–as much as 150 times more!–than from purple-spotted flowers. So, if a bee is looking to get the most pollen for its effort, the bee is going to pretty much ignore the purple-spotted–older–flowers and just forage on the white-spotted fresh flowers.

 

This is good for the bee because it can be a more efficient pollen-gatherer–and it is good for the bluebonnet because the white spot directs bees to flowers with good, fertile pollen and the transfer of this pollen is likely to result in successful cross-pollination for the bluebonnet.

 

I have often heard that the purple spot is the result of pollination. I will hear that flowers with white spots are not yet pollinated while those with purple spots are already pollinated. I’m still wondering a bit about this. In the Schall and Leverich paper, they said that the spot color change was not related to pollination or fertilization. 

 

But . . . several papers from UC–Davis (the hotspot for studies on flower preservation) indicate that an increase in ethylene production can be triggered by pollination. 

 

So I think this means that the color change would occur anyway, regardless of whether or not pollination occurred. But if pollination does occur, it increases the amount of ethylene and the color change would happen faster.

 

Ethylene is a chemical compound produced by plants. It is responsible for many plant processes, but you are probably most familiar with its role in fruit ripening. Have you noticed that when a bunch of bananas ripen, it happens to the whole bunch at the same time? That’s because of the release of ethylene. 

 

Heard the old saying about “one bad apple can spoil the whole barrel?”  Again, that’s because of ethylene production. Once one apple starts the ripening process, it releases ethylene gas and ends up starting the ripening process in the whole barrel–or plastic bag. Growers will ship green fruits to a distribution center where they will be gassed with ethylene to start the ripening process before being sent to your neighborhood store. 

 

That is probably more than you wanted to learn about a bee’s visit to a bluebonnet, but I’m going to keep an eye out this spring and watch which flowers the bees visit. And I’m going to pick out the bad apples quickly–and maybe I’ll separate my bananas too.

 

 

Pollination and Banner Markings in Lupinus texensis (Leguminosae), Barbara A. Schaal and Wesley J. Leverich, The Southwestern Naturalist, Vol. 25, No. 2 (May 15, 1980), pp. 280-282 

The Effect of Pollination and Ethylene on the Colour Change of the Banner Spot ofLupinus albifrons (Bentham) Flowers. A. D. Stead and M.S. Reid. Ann Bot (1990) 66(6): 655-663

Pollination ecology and the significance of floral color change in Lupinus pilosus L. (Fabaceae) 
Ne'Eman, G | Nesher, R; Israel Journal of Plant Sciences [ISR. J. PLANT SCI.]. Vol. 43, no. 2, pp. 135-145. 1995.