Honeybee Botany and Dr. Paul Arnold

Tonight at the Metro Atlanta Beekeepers' meeting, Dr. Paul Arnold spoke to us about Honeybee Botany. Paul is a professor and researcher at Young Harris College and I have met him several times. He spoke to us last year about palynology and he was one of the teachers in the Journey(wo)man course I took at Young Harris.

He talked tonight about basic plant biology - the difference in fertilization and pollination as well as the parts of the plant and how they function. I had learned all about perfect and imperfect flowers at Young Harris. Here's a summary of my notes:

1. He described the two types of imperfect flowers: Monoecious and Dioecious. These two terms have Latin roots. Mono means "one" and Di means "two" The "Ecious" part comes from the same root as "ecology" and means "house" So if Monoecious means "one house" that refers to a plant in which the staminate and pistillate flowers are both on the same plant - like corn and cucumber. A Dioecious or "two house" plant refers to a plant that has staminate and pistillate flowers on different plants - such as holly where there is a male and female shrub or the ginko tree where there are male and female trees.

2. Bees find the flowers that they pollinate in several ways - some flowers have UV markers on their petals. Bees don't see red so if they are attracted to a red flower, it is not because of the color, but rather because of something else like UV markers or scent. Bees seek out flowers which will give them the reward of nectar or pollen. Sometimes the scent of the flower draws the bee.

3. Bees make good pollinators for several reasons. First they have perennial colonies which have large populations (lots of pollinators). Second, bees only eat nectar and pollen - they don't eat anything else and aquiring nectar or pollen results in pollination every time the bees seeks food. Bees have plumose body hairs that collect pollen easily ("plumose" means having feathery hair as bees do all over their bodies). Bees tend to stick to one type flower per trip. So if a bee goes out foraging to get nectar from the holly tree, she moves from holly flower to holly flower, rather than to two or three kinds of flowers at once. This makes it easy for her to carry pollen from one holly flower to another. Finally bees are good pollinators because the hives can be manipulated as well as moved to increase effectiveness.

4. The attractants for bees to flowers include sight: nectar guides on petals, color, pattern, and movement of the flower
and scent: the bees hold the scent memory for up to five days.

Finally he got to an explanation of my abelia.

5. Some plants, including abelia (I asked him), have "extra-floral nectaries." Looking at the trumpet shape of the abelia flower, it's hard to imagine a little honeybee sticking her body in far enough to stick her tongue in far enough to get the nectar. But as I reported in last night's post, both the bunblebees and the honeybees appeared to be getting nectar from where the flower meets the sepals.

In many flowers, the nectary is in the center of the bloom. But in the case of abelia and tulip poplar and many others, there is an extra-floral nectary. This is exactly what it sounds like: a nectar source outside the petals of the flower. This is the case with abelia and this explains why the bees are hanging on the outside of the flower to get to the nectary at its base.


If you enlarge this picture by clicking on it, you can see that the bumblebee is on the outside of the flower, slurping nectar from the extra-floral nectary.

The Difference in a Palynlogist and a Pollenologist

is my spelling error! Horrors!

I have been appalled that "ginormous" is now a word that is accepted and is in the dictionary. I certainly don't want to supply any more terrible contributions to the English language, so I want to do my part to rectify an error.

Dr. Paul Arnold is a "Palynologist" not whatever I labeled him earlier (not writing it again to avoid continuing the trend in the ginormous direction.)

OK, so let's look at the word. Wikipedia says

"Palynology is the science that studies contemporary and fossil palynomorphs, including pollen, spores, dinoflagellate cysts, acritarchs, chitinozoans and scolecodonts, together with particulate organic matter (POM) and kerogen found in sedimentary rocks and sediments. Palynology does not include diatoms, foraminiferans or other organisms with silicaceous or calcareous exoskeletons."
I heard from Dr. Arnold today about the analysis of my pollen sample. Here is what he said:

"Sorry it has taken me so long to look at your specimen! You had what seemed to be quite a bit of tulip poplar, and some magnolia pollen. Also, quite a bit of rosaceous pollen was found in your specimen (possibly blackberry, strawberry, apple, etc.). Holly pollen was also present in pretty large amounts, as was another very large pollen grain which I have not seen before. I keyed it out through my pollen keys, and it seemed to lead me to either a type of lily or yucca plant. I’m not 100% sure about this last grain, since I have never made a reference slide of yucca, but I wouldn’t rule that possibility out. All in all, a pretty typical spring woodland honey (with the exception of that last grain)."

I wrote back that this super was filled by the bees in early July - actually late June/early July.

Here's his response (what a nice guy - he ran my specimen again.)

"This confuses me too. There are some pollens that can be confused with poplar, but most of these are spring pollens as well. One of these “poplar mimics” are various species of the buttercup family. It would tend to be unusual to find large amounts of this unless there are various ornamental buttercups in your area, or a meadow full of native buttercups (some do persist into July). The only other thing that I can think of is that the bees may have been collecting residual pollen from old blooms or other surfaces. If they were doing that then that means that they were not collecting nectar from these residual sources. One possible support of this idea is, because of the unusual year, I saw many poplar blooms in the piedmont area persisting into late June, quite a few weeks past when I usually see them. We actually had almost no poplar bloom up here due to a warm early spring followed by a late heavy frost. Another explanation is that possibly there may be other types of ornamentals in your neighborhood that are neither in my pollen key, image databases, or from reference slides that I have collected that mimic those golden-yellow poplar grains. So, as you can see, I’m just as puzzled as you. After I received your e-mail, I actually spinned down another aliquot of your sample to check its contents. Once again, the golden-yellow poplar grains seemed to be present, but I found an additional pollen that I don’t remember seeing in your previous sample . . . sumac. Do you have any smooth or winged sumac in your area? This would tend to darken your honey somewhat. Holly was certainly a very significant part of your sample (there is no confusing these grains with anything else), although I can’t narrow it down to species. This is actually also a little unusual for so late in the year, unless you have quite a few late blooming ornamental hollies in your area (most native hollies have bloomed out by mid June). It sure would be interesting to try again next year at the same time to see if you get the same type of honey."

and he straightened me out about the spelling of what he does: PALYNOLOGIST
For those of you who care about words like I do, here is Wikipedia's description of how the term originated:

"The term palynology was introduced by Hyde and Williams in 1944, following correspondence with the Swedish geologist Antevs, in the pages of the Pollen Analysis Circular (one of the first journals devoted to pollen analysis, produced by Paul Sears in North America). Hyde and Williams chose palynology on the basis of the Greek words paluno meaning 'to sprinkle' and pale meaning 'dust' (and thus similar to the Latin word pollen).[5"

So there you go - and down with English additions like ginormous.....

Meeting a Melissa Pollinologist

I haven't ever met a melissa pollinologist until the meeting of the Metro Atlanta Beekeepers Association this past week. Our speaker was Dr. Paul Arnold and he refers to himself as such. Paul Arnold is one of the founders of the Young Harris Beekeeping Institute which I attended in May and has taught in the biology department of Young Harris College for 19 years.

He said that he is one of the few people in the country who analyzes honey to determine what pollen contributed to the honey. More people are melissa pollinologists in Europe and Australia. I was one of the nine or so people in the club who drew the straw that allowed us to bring out honey to him to take back to Young Harris and analyze.

Dr. Arnold told us that many people wonder why would one want to analyze honey for the pollen. There were four reasons:

• To determine the nectar source for marketing purposes
• You can't say for sure your honey is sourwood, for example, without this analysis
  
• To determine undesirable nectar sources
• This year there was an abundance of mountain laurel in the N Georgia mountains and because of the late hard freeze, the bees had little else from which to choose. As a result they made a ton of mountain laurel honey with is poisonous and smells like brake fluid.
  
• To verify a pollen contract
• If the person who hired the beekeeper wants to know if the bees he hired actually visited his almonds or blueberries
  
• To determine the source of a pesticide kill
• If bees are dead in droves around the hive, analyzing the honey may give you the source of the kill

There are many drawbacks (he had slide after slide about this) to doing pollen analysis. Among the drawbacks are:

• Equipment cost - microscope, centrifuge, slides, etc.
• Many pollens look alike so it's hard to come to an answer
• There are few pollen guides on the subject

Dr. Arnold makes his own reference slides when he finally gets down to an identification

He had a series of slides which were a lot of fun to see showing the notable characteristics of various pollens:

• Size: tupelo, for example is very large, dandelion is very small
• Shape: pollen is sometimes triangular, 4-lobed, football shaped, round, winged, etc.
• Wall apertures (openings)
• Wall ornamentation (spikes, knobs, pits)

What he does in the process is:

He mixes 50% honey and 50% hot water. He mixes this well and then centrifuges it at 1500 RPMs for 5 minutes. He then pours off the liquid and there is a pollen pellet at the bottom. He pipettes this out onto slides and looks at it under a low light microscope.

I left my dark honey with him. He had said the less filtered the better, so I put some from a cut comb box of the dark into a jar and left it for him. I've been mystified by this honey because it is very dark - less dark this year - but still very dark. The bees made this honey while I was gone over the week of July 4th. I know this because the hive had no honey in any super before I left and this super was full when I came back.

Dr. Arnold did say that the dark honey in Georgia late in the season is often made from smooth sumac or catalpa. It will likely be weeks before I know the answer about my particular honey because he spends about 30 minutes processing each individual sample. He was very kind to do this for our club, and all he gets for the effort is our appreciation and a taste of each honey sample!

So I was very glad he shed a little light on the dark late season honey before he ended his interesting talk at the bee club.

I feel very lucky that he was so generous to our club - taking home members' honey samples to analyze.