Flesh-Eating Swarms

By Adrienne Montgomerie

The buzzing starts faintly, then grows. Around and around your head, there is buzzing. Then two buzzing things, then you are surrounded by dozens of flying yellow bodies that… go on their way. Because the meat they’re looking to feed on is not you.

You might think of a sting when you think of bees, and you most definitely think of honey. But I bet you picture their fuzzy little legs heavy with yellow pollen from flowers, not a toothy grin, ripping into flesh.

A Wide World of Bees

There are almost 20 000 types of bees, and there only five types that eat meat. Common names for these flesh-eating bees include vulture bees and carrion bees. The scientific name is for this family of bees is Tragona.

They aren’t known to go out and hunt down prey. These aren’t the killer bees of folklore. These bees don’t even have a stinger!

Vulture bees typically gnaw on carrion, like vultures do. Carrion is an animal that is already dead. The only reason these bees seem to bother with living things is to keep them away from their food.

Sharing the Meat

Vulture bees usually take the bits of meat they gnaw off a dead thing back to the hive. There they spit it up (regurgitate it) as food for baby bees (larvae). This is their only source of protein. They don’t feed on flowers or collect pollen the way that other types of bees do. Their hive still produces honey though, and it is a lot like the honey we put on toast and in tea.

Some other types of bees bring meat back to the nest, but they’re using it as a building material. Those bees don’t eat the meat.

Tracking Vulture Bees

To find a vulture bee, you could try Mexico, but you’re better off going farther south to South America.

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Photo of Tragona by José Reynaldo da Fonseca - Own work, CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=969999

Suspense in the Kitchen

By Simon Shapiro

What do these things have in common: milk and butter? Of course they're delicious dairy foods. How about milk, butter and balsamic vinaigrette? Still delicious foods, but no longer dairy. What if we add Polysporin to the list (or hand lotion or hair conditioner)? No longer foods and probably not delicious, though — full disclosure — I've never tasted Polysporin. But what they do have in common is that they're all emulsions.

An emulsion is a mixture of two liquids that don't usually mix. Small droplets of the one liquid are suspended in the other. Oil and vinegar are a good example. You've probably done this: you make a salad dressing using three parts oil and one part vinegar by whisking them together, or shaking them in a bottle. This makes a nicely blended mixture. But not for long. The dressing soon separates into an oil layer floating on a vinegar layer. When you pour some of that on your salad, you get all oil and no vinegar. That's because the emulsion isn't stable. 

 

A layer of  liquid II floating on liquid I

 

All shook up: Droplets of II are dispersed in I. This is an emulsion.

But an unstable emulsion separates into the original two layers.

Milk, by contrast, is a stable emulsion of oil droplets in water. And butter is a stable emulsion of water droplets in oil. Most commercial salad dressings are stable emulsions of vinegar in oil.

So how do you get your salad dressing to be stable? You introduce a chemical —an emulsifier—which will stop the two liquids from separating. The most common way the emulsifier works is this: it's a molecule, one end of which binds to oil, and the other end binds to water. So the emulsifier is active at the oil/water surface and prevents the drops of water (or vinegar) from separating out of the oil. 

With an emulsifier attached to the droplets of II, this is a stable emulsion.

While adding a chemical emulsifier sounds distasteful, but it isn't. Mayonnaise is a great example of a very stable emulsion. The secret emulsifier is lecithin, which is in the egg yolk that's used to make mayonnaise. Lecithin also occurs in soya beans, and soy lecithin is a common emulsifier. So too, are mono- and diglycerides. While these may sound like nasty, synthetic chemicals, they occur naturally in seed oils, which is normally the raw material from which they are produced (though sometimes animal fats are used instead: vegetarians and vegans beware).

Molecular model of soy lecithin

 

Other common emulsifiers for home-made salad dressings are mustard and honey. Now you know why those ingredients are often included in recipes for salad dressings. It's not just because of the taste. 

Emulsion Factoids

White Milk and Blue Milk

I wrote earlier that milk is a stable emulsion of oil in water. That's only partly true. If you let unprocessed milk stand, it will partially separate: cream will rise to the top. Literally. To make milk totally stable it has to be homogenized. This is a purely mechanical (not chemical) process. The milk is forced through a small nozzle which ensures that the droplets of fat are all small. That's enough to stabilize the emulsion. Full fat and even 2% milk appears white. Milky white. That's because the suspended fat particles are dense enough to reflect the full spectrum of ambient light. Anything that reflects all the colours appears white. 

But skim (or non-fat) milk doesn't have fat particles. The (relatively) big fat globules are gone, and what's left are mostly casein proteins suspended in water. This mixture doesn't reflect all wave lengths (colours) equally. The "Tyndall Effect" describes what happens: shorter wave length (blue) light is reflected more than longer wave length (red) light. Since more blue light is reflected, skim milk appears to have a blueish tinge.

Ole Blue Eyes

Unexpectedly, blue eyes don't have blue pigment in the iris. Irises have a translucent layer with particles of melanin suspended. And you guessed right. The particles of melanin reflect shorter wave length blue light more than longer wave length red light. And that's why blue eyes are blue.

The Ouzo Effect

Ouzo is an anise-flavoured liquor, common in Greece. Although it's a clear liquid, when you pour water into it, it becomes cloudy white. Here's why. Ouzo contains anise oil which dissolves in alcohol, but not in water. When the water is added to the Ouzo (alcohol/anise oil mixture), the alcohol itself dissolves in the water. That gives the anise oil a problem, so it leaves the water/alcohol mixture, forming tiny droplets of anise oil suspended in the water/alcohol—a stable emulsion. This phenomenon is called spontaneous emulsion. The emulsion is dense enough to reflect all light, and so the mixture looks white. We also know that if you keep diluting it, it will get a blue tinge.

Insect Mimicry; Caterpillar Predators; Baby Snapping Turtles & Bird Eggs: Jan Thornhill Blog Post Updates

by Jan Thornhill 

This week's blog post was going to be about mimicry. I'd come across an insect in Chile that  was a fabulous example of automimicry – the kind where part of an animal's body looks like a more vulnerable part. 

Here's the first view I had of this insect:

"What a character!" I thought.  Kinda cute, and kinda homely at the same time, like an old shoe. 

Then I changed my camera angle...

...and saw that what I'd thought was a face was actually the insect's rear end. 

How fabulous – it's abdomen was pretty much a replica of its head, complete with bulging red eyeballs! 

If anyone knows anything about this beetle(?), I'd love to hear from you!!

And that was it. Kind of short for a blog post. But then I realized I'd already written a post about mimicry (Spider Art and Bioluminescent “Bombs”: Extreme Animal Mimicry) – and that I should just add this guy to that post as an update. And then I remembered more updates I needed to do.

Update # 2:

It seems like a no brainer to add this find to a post about cabbage moth caterpillars I wrote a couple of years ago, Wild Helpers in the Brussels Sprouts Patch. 

I found a tiny clay urn glued to our outdoor table yesterday. I knew it was some kind of wasp nest. I also knew that the tiny pot was going to be destroyed one way or another, so instead of leaving it to be crushed by a coffee cup or plate of sliced tomatoes, I sliced it off the table with a knife so I could see what was going on inside.

Oooh! 

The urn was built by a Potter Wasp nest – someone in the genus Eumenes. 

Potter Wasp, Eumenes sp. (Wikipedia)

Potter Wasps normally won't bother you. What they will do is construct tiny, marble-sized urns out of drops of mud.

Potter wasps sometimes include an urn "neck."

They fill these little pots with paralyzed caterpillars, then lay an egg on the inside clay surface. If all goes well, the egg will hatch and the wasp larva will feed on the caterpillars until it's mature enough to chew its way out of the pot and start its adult life.  

I don't think the egg in the one I found one "took." Or maybe something happened to the builder before she could lay an egg. Too bad, since there were five different desiccated caterpillars inside, one of which, judging by its pale green colour, was surely a cabbage caterpillar. 

A feast gone to waste.

Update # 3

A few weeks ago I wrote a post about a bird egg collection I donated to the Royal Ontario Museum, I Might Be a Criminal. I sent a link of the blog to the ROM's Mark Peck, who, in response, told me about a Canadian citizen scientist nest monitoring program that anyone can join: Project NestWatch. 

It looks like a fun summer project. A little late now, but there's always next year! Go to their website to see how It works:

Step 1:  Register for Project NestWatch 

Step 2:  Learn how to find and monitor nests using the resources provided on this site

Step 3:  Search for nests around your home, school, cottage, or elsewhere

Step 4:  Monitor your nest(s) throughout the breeding season

Step 5:  Submit your data online and contribute to Canada's national nest records database!

Update # 4:

I wrote a post a few years ago about helping snapping turtles on our road, A Baby Snapping Turtle Success Story. Snappers have been nesting on and near that same bridge for years. Then the county decided to replace the bridge. But what about the eggs that had already been laid? Solution: my neighbour Tracy and her daughter gathered the eggs and took them to the Ontario Turtle Conservation Centre (previously the Kawartha Turtle Trauma Centre) where they were incubated. Tracy picked them up when they hatched and sent me pictures of their release. 

Photos by Tracy Dafoe

Another friend brought 50 snapper eggs to the Ontario Turtle Conservation Centre a few weeks ago. At that point, the centre was already incubating 3,000 eggs! Please consider helping them in this important work!  

The Art of Presenting Science = Literally!

Post by Helaine Becker

I had the great pleasure of working with illustrator Dow Phumiruk on Counting on Katherine: How Katherine Johnson Saved Apollo 13, which "launched" earlier this summer.

Dow's artwork, in my opinion, is stunning, and really brought the book to the next level. I was curious as to how she blended her knowledge of math and science with her artwork to create such effective illustrations. So I asked her.

Here is the result of that interview:

H: Your artwork in Counting on Katherine is so beautiful. But it's more than that - I can tell that it's historically accurate too. Can you describe your process - how did you research the illustrations in Counting on Katherine?

D: So much research!!

I started with online sources from NASA. I also watched online interviews with Katherine Johnson herself, which I found to be the most helpful to learn about her personality. I read about the start of NASA, about the solar system. I filled a folder on my computer with screenshots of images I thought might be useful for reference. I read the Hidden Figures narrative nonfiction book by Margot Shetterly (the movie did not come out until after my final art was turned in). I made trips to the library to look through books about space. I also looked at maps and images of what West Virginia looked like in the 1930s, including the Greenbrier Inn in her hometown, and what her classrooms might have looked like back then. I looked at online clothing ads and patterns as well as old photographs to see what styles of clothing best represented the fashion of each phase of her life. And of course, I found as many photographs of Katherine herself at different ages.

H: What were the biggest challenges? Biggest surprises?

D: The biggest challenge was the above-described quest for accuracy, from the math to the scenery from her childhood. It was really difficult to find enough photo reference from that long ago. Little details were hard to discern, like if her family might have owned a car upon moving to Institute, West Virginia. In addition, her achievements spanned decades, and this meant learning as much as I could about the evolution of our space program over this long period of time.

I was surprised about Katherine in general. I didn't know who she was upon receiving the pitch for this project. I couldn't believe I had not heard of her before. The more I learned about her life, the more I grew inspired!

H: The endpapers are stunning. They show a blackboard covered with mathematical equations and math problems. How did you, a)think to do this for the book, and b) come up with the material to put on the board?  

D:  I wanted to represent Katherine's genius with math-filled chalkboards. Picturing her as a young girl in front of these chalkboards made sense to emphasize the extent of her abilities since early childhood.

Coming up with the information to fill the chalkboards was not easy! I may have been proficient at math in my youth, but now advanced math is a challenge. Basic algebra and word problems, like the picnic pies and the rocket ship questions, are not a problem for me to make up. I was able to easily google search equations for circumference, radius, volumes of different shapes for example, to make up the ice cream cone question (in which I do not clarify is the volume of the parts of a one scoop cone, by the way!). Sometimes, as for the rocket ship trajectory question, I’d leave off needed information to answer the question (so that I wouldn't need to have an answer!).

  

I used multiple sources for the rest and especially for the higher level math and physics seen in the book. I got lots of help from my family, sampling bits from my girls' homework (their work spanned algebra to calculus) and basic physics equations from my husband’s old physics book (he is a former engineer). I also found some information online, altering the source by replacing letters and figures so it would not be just copied. In compiling this together to fill the board, I would sometimes intentionally obscure parts.

In the end, I would remind myself that this is a book about a mathematician and her brilliance and not a math textbook to keep myself from hyperventilating.

What projects are you working on now???

I have a couple books in the works, but they have not been announced yet. I will say that I am very excited to be both author and illustrator for these upcoming projects!