Wild Helpers in the Brussels Sprouts Patch: Caterpillar Predators

by Jan Thornhill

Brussels sprouts look ridiculous! (Wikipedia)

The first time I saw Brussels sprouts clinging to their stems on the back of a truck in Holland in 1977, I was shocked. Up until then, I’d always thought they were baby cabbages. I still can't believe no one told me how they grew.

Cabbages, Brussels sprouts, cauliflower
and kohlrabi are all the same species.

We’ve had a large organic vegetable garden for over 25 years. For most of those years we’ve tried to grow various brassicas—broccoli, cabbage, kale, kohlrabi, cauliflower, and, yes, Brussels sprouts.

A pretty pest—the cabbage white butterfly (Wikipedia)

Every year, though, we’ve been inundated with cabbage butterflies and their progeny—cabbage-loving green caterpillars. The common Cabbage White Butterfly (Pieris rapae) is native to Europe, Asia and North Africa. There were none here until it was accidentally introduced to Quebec in 1860. Because there are plenty of wild Brassica species in North America, it spread like crazy. Now it's everywhere.

A hungry cabbage caterpillar (Wikipedia)

 Its caterpillars are fast-growing voracious feeders and can easily turn a gorgeous, giant cabbage into multiple, disgusting layers of green lace glued together with caterpillar droppings. Yuck! Damage can be controlled organically by applying products containing the bacterium Bacillus thuringiensis (Bt), but I’ve always been too cheap to buy it so we’ve always hand-picked eggs and caterpillars. 

This year we decided in the spring to be lazy and only grow Brussels sprouts and nothing else from the cabbage family. Surely two of us could keep on top of the caterpillars on only four plants! And we did—though we also had help.

Helper #1: Chipping Sparrow

Audubon's Chipping Sparrow from his elephant portfolio

One morning I saw a Chipping Sparrow emerge from between the big leaves of one of the plants. It had a juicy green caterpillar in its beak! The sparrow and its mate returned over and over again for several days, each time flying off with a caterpillar. We could sit back and relax! We didn’t notice when they stopped coming, which probably coincided with their young becoming independent. Suddenly we were inundated with caterpillars again.    

Helper #2: Nursery Web Spider

Pisaurina mira, the Nursery Web Spider, can
have a broad stripe down its back. (Jan Thornhill)

While picking off yet another crop of caterpillars, I came face to face with a giant spider—giant enough that I jumped backwards when I saw it. It was a Nursery Web Spider (Pisaurina mira) and it had a large caterpillar in its jaws. It was sucking the life from it. 

Nursery Web Spider sucking the juices from a cabbage caterpillar. (Jan Thornhill)

Helper #3: Paper Wasp

Polistes fuscatus, our common native paper wasp removing fecal matter
from a caterpillar that was too heavy to carry. (Jan Thornhill)

This one was the best one. While hand-picking caterpillars, I suddenly spied a large paper wasp, the native Polistes fuscatus. I normally don't like these guys because their sting can feel like a combination of being electrocuted and burned with a soldering iron. This one, however, had no interest in me. It was trying to take off with a large caterpillar held between its mandibles. But it was too heavy and the wasp only made it as far as one of the outer leaves. It landed with the caterpillar and then started fussing over it. 

At first I thought it was simply eating the caterpillar on the spot, but after a few minutes I figured out what it was doing: it was cleverly removing the heavy fecal matter from the caterpillar. When it was done, it easily flew away with the lighter carcass, leaving behind a line of green poo. 

I'm happy with any help I can get controlling the Cabbage White Butterfly, but do I want it to disappear? No, I don't. And in Great Britain, where they once had flocks of millions, they're looking at its disappearance as a real possibility. Between 1976 and 2008, its numbers have declined by a third—which is pretty astonishing. The crash in its population is likely due to the drop in the number of home vegetable gardens combined with commercial crops being sprayed with pesticides. If the Cabbage White Butterfly disappeared from here, sparrows, wasps and spiders would all lose part of their diets. 

The garden nasturtium is both tasty and a good
decoy plant for the Cabbage White Butterfly 

One more little snippet—apparently cabbage caterpillars will eat garden nasturtiums, which are a lovely salad addition (both flowers and leaves), so they can be used as a decoy crop. The caterpillars, however, much prefer cabbage leaves—if a caterpillar gets even a tiny taste of a cabbage leaf first, it will starve itself to death rather than eat nasturtiums!

Update: August 21, 2018

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.

References: 

Article about U.K. Cabbage White Butterflies: Cabbage Whites Under Threat

 

What's the Source?

by Helen Mason

What is a lemato? Is this one?

 Does use of the same or similar wording in more than one article about the same topic set your alarm bells ringing?

In 2013, I was working on Agricultural Inventions: At the Top of the Field, a science book for kids in grades 5 to 8. In my search for genetically modified foods I kept coming across references to the lemato. According to the sources, this is a cross between a lemon and a tomato.

One site talked about mixing a tomato and a lemon seed. Another discussed how the cross was made solely to test whether researchers could find a way to make a tomato smell like a lemon. An article for students talked about the health benefits of crossing an antioxidant such as a tomato with a fragrant citrus fruit such as the lemon.

Or this?

Almost all appeared with a picture similar to the one at the right from a Portuguese student web site. Some had one similar to the photo at the top. Another showed a fruit that was tomato at the bottom and lemon at the top, including the skin. The author claimed not to have used photo-shop. Really?

Several sites criticized the use of GM. Few referred to the original researchers. It was them I wanted to find—and fortunately I did.

Since the lemato was developed at Israel's Newe Ya'ar Research Centre and I don't read Hebrew, I researched SciTech news sites. The lemato is a tomato that includes a gene from a variety of lemon basil. Basil, that's the annual herb that's a member of the mint family and not a citrus fruit.

Would a pic like this draw you into an article about lematos?

So what's the message for online researchers? First, don't believe everything you hear or see on the Internet. Second, remember that many sites are like movie tabloids. Correct information might be present—but you have to get beyond the hype.

And no, I still haven't seen a lemato. But I suspect that it looks like a regular tomato. Researchers suggest that it has a different smell, however.

 Helen Mason's most recent books include What is Digital Entrepreneurship, Be an Active Citizen in Your Community, and Be an Active Citizen at Your School, all Crabtree, 2016.

Cupping Bruises May Confuse Forensic Scientists

by L. E. Carmichael

Via Amy Selleck on Wikimedia Commons

If you had any exposure to the Rio Olympics at all, you probably noticed the giant hickeys several athletes - most notably Michael Phelps - were flaunting all over their events. Attacks by enormous octopodi? Nope. Cupping bruises.

If you've had any exposure to the internet since the Olympics, you've probably learned that cupping is a procedure from traditional Chinese medicine that involves creating a vacuum inside a glass or plastic cup, then applying the cup to the skin. Skin and tissue get sucked up into the cup. This increases circulation to the site, which could speed healing. So, in theory, could the suction itself. As my massage therapist explained it, massage involves "unsticking" tissues by pressing down, whereas cupping unsticks them by pulling up.

Western science has yet to find evidence that cupping actually works, which is not entirely surprising, given the nature of the treatment. As my massage guy also pointed out, it's pretty hard to do a double blind study on a treatment that creates a distinct physical sensation and a giant hickey. But that's OK, because this post is not about whether cupping works.

It's about the giant hickeys, which are formed when blood rushes into the skin below the cup, causing the tiny blood vessels to burst.

Here's a fact about cupping marks those Olympic stories didn't mention - they look an awful lot like bruises left by particular types of blunt force trauma. Specifically, the kind found in cases of child, domestic, and elder abuse. Depending on circumstances, cupping marks can also look like lividity - the pooling of the blood after death.

This, as you can imagine, is a problem, not for athletes, but forensic scientists. If pathologists don't know about cupping and the kinds of marks it leaves, they could interpret those marks as signs of foul play, confusing a criminal investigation.

Something like that happened in Turkey in 2015. A 40-year-old man died during surgery to repair shotgun injuries. Most people would assume the shotgun was to blame for his death, but the attending doctor saw round bruises and ordered an autopsy for further investigation. It wasn't until police interviewed family members that the bruises were identified as cupping marks from the victim's regular treatments, rather than signs of violence that contributed to his death.

Which just goes to show that being a forensic scientist is a really, really hard job, because you have to know pretty much everything about everything.

Did you watch the Olympics? Have fun playing "connect the dots" with the athlete's cupping marks? Did their endorsement make you want to try it?

Want to know more about being a forensic scientist? Check out my latest book for young readers, Discover Forensic Science!

Clam Gardens Revisited

Ever dig clams on a beach? If you had to race razor clams as they ducked away in sand, it's easy to think "There HAS to be a better way!" But if you scraped for butter clams only a few inches down in the stony muck of a clam garden, you'd know that clam gardens ARE a better way.

Clam gardens are beaches modified by First Nations people on shorelines along the West Coast, to increase and improve the habitat for clams that are particularly tasty and easy to gather. Back in 2011, I was lucky to be a volunteer helping biologist Amy Grosbeck in her study of clam gardens, and wrote for Sci/Why about the experience. Click here to read that post and see some excellent photos by that scientist. Amy Grosbeck and her colleagues went on to write a journal article about their study (and it's really interesting to read).

Amy called me up this summer to offer another chance to volunteer to help her with another study. Hurray! My spouse Bernie and I were glad to join her on Quadra Island, to take some samples and tidy the clam gardens she was studying this summer. We stayed a few nights in a bunkhouse maintained by the Tula Foundation for the Hakai Institute, which supports intertidal biology research by Amy and many of her colleagues.

At 4am, you better have a headlamp!

Studying intertidal biology means getting up before dawn, and getting to our launch point at Granite Bay before low tide.We left the bunkhouse at four o'clock in the morning, after a quick breakfast. Amy and Bernie paddled a canoe loaded with pails of scientific gear, while I paddled alongside in my inflatable kayak (The Lagoon is a very practical boat, sent to me by Advanced Elements, and a big improvement on the already excellent version I paddled on my 2011 trip with Amy.)

When the sun came up, we could see clouds, fog, and rain all around Kanish Bay.

Paddling in a light drizzle of rain at 4:30am was made more interesting by the swirls of phosphorescence in the water. Every time our boats moved, the water would sparkle with tiny specks of light made by plankton. If there had been a moon or lots of electric lights, the dim sparkles wouldn't show. On that dark early morning, the swirls of light were amazing. Each stroke of a canoe paddle left big swooshes of light, and my kayak was skimming on waves of sparkles. Then we paddled over a bed of kelp, which lit up with the movements of fish and shrimp. Too bad the sparkles are too dim to photograph well with ordinary cameras. The light show made getting up so early seem worthwhile.

It seemed even more worthwhile when we got to the clam garden and learned how much work Amy had been doing there. Quickly she showed Bernie how to take samples of the beach material -- stony sand mixed with broken clam shells and muck -- while she and I gathered up sample bags she had fastened to metal rods driven into the beach at intervals.

Somehow we got all the samples taken, all the bags gathered, and all the rods retrieved before the rising tide covered her sample sites. The beach was tidied up at the end of Amy's study season, and our work was done.

And then we did it all again the next day on new beaches. Science! Paddling at 4:30 am in the rain for science! Soaked to the skin all day for science! It was worth it, and I'll go again when Amy calls me to come do for a few days what she does over and over many times a year.. To be an intertidal ecologist for a few days, gathering data for scientific studies, is a wonderful opportunity.

I wrote an illustrated book - about invisible stuff!

By Claire Eamer

Cover art by Marie-Eve Tremblay.
Published by Kids Can Press.

My latest kids' science book - Inside Your Insides: A Guide to the Microbes That Call You Home - hits the bookstore shelves on Tuesday, September 6. And I'm thrilled.

I know, I know - I've been here before. After all, this is my seventh kids' book. But the launch of a new book never loses its charm. There's a long and sometimes painful road from the first exciting bit of research to the finished object - all shiny and glossy and colourful, and just waiting to delight fresh eyes.

This time there's an extra level of delight, at least for me. The topic of the book is the invisible menagerie of tiny critters that make up the human microbiome. The key word here is "invisible." And a key aspect of kids' books is illustration. So, how do you illustrate the invisible?

One solution might have been photographs. Microbes aren't really invisible - just really, really small. You can see some of them through a light microscope and more through an electron microscope, but some are barely visible even with the best equipment. And they....well....they look a bit boring. (Sorry, microbiologists! I know you love them all.)

EHEC bacteria, O104:H4 outbreak strain. Scanning electron microscopy. Bar: 1 µmSource: Gudrun Holland, Michael Laue/RKI

The better solution is an artist - in this case, the marvellous Quebec artist and illustrator Marie-Eve Tremblay.

I should explain that the publisher, Kids Can Press, came up with this solution. I just sent them words and then sat back and crossed my fingers, hoping they'd find a way to bring the book to visual life.

And they certainly did. Marie-Eve's microbes have character, humour, colour, emotion. Not bad for mostly-single-cell organisms. They might not be exactly what a microbiologist sees, but they get some fairly difficult information across in a way that will engage the kids reading the book.

And, who knows? Some of those kids might be the next generation of microbiologists. I hope so!

Thanks, Kids Can Press and Marie-Eve Tremblay, for making my words come to colourful and entertaining life.

If you want to know what reviewers think of the book, check out the reviews in Quill & Quire, School Library Journal, and Kirkus Reviews.

And for some cool information about researching the human microbiome - and keeping your research up to date - see Jan Thornhill's Sci/Why post from March of this year.