Friday, October 31, 2008

"Insects and Gardens"

Before I quit posting for the day, I want to recommend a great book for anyone who wants to learn more about insects - or for anyone who gardens.

The book is Insects and Gardens by Eric Grissell, and it is a wonderfully readable book that discusses, often humorously, the roles that insects play in our gardens and our yards. The pictures are phenomenal too, making my photos look like the amateurish attempts that they are.

For anyone looking for Christmas gifts for a gardener or a budding naturalist, I can't think of a better gift to add to your Christmas list!

The Flying Confetti Garden, Part IV

The last insects that I'm going to highlight from my "aster collection" are a pair of bees that are often mistaken for each other - the bumble bee and the carpenter bee. They are about the same size (which means big, about 1" or so) and both are colored black and yellow. There's a straightforward way to tell them apart, though.

The bumble bee, the more "well known" of the two, has a hairy abdomen which is very visible in this photo.... Bumble bees generally nest in the ground in abandoned rodent nests, where a queen bumble bee creates a small colony of workers over the course of the summer. Reproductive males and females are raised in the colonies at the end of summer, and it is only the fertilized young queens that survive the winter to start new colonies the next year.

The carpenter bee, on the other hand, nests in unpainted or soft wood and has a generally hairless abdomen, which is easy to see in this photo. Carpenter bees eat out straight holes into wood, then create a few cells all in a line that they pack with pollen and nectar before laying 1 egg in each cell and capping it. Carpenter bees are often considered pests because of these holes that they create in the trim around porches, doors, railings, etc., but they also nest in dead trees and other wood.
Male carpenter bees, which do not have stingers (egglayers), are particularly noticeable and frightening at certain times of the year, as they zoom back and forth protecting their territory, waiting for females to come along so they can mate. Without stingers, their buzz is much worse than their "bite", but they certainly can be startling and rather disconcerting.

Both carpenter bees and bumble bees are important native pollinators. The photo below of a carpenter bee shows pollen dusting its head and body, pollen that will go along with the bee to the next flower where it can cross pollinate that flower and help create the next generation of plants, as well as the next generation of bees.

With honeybees having so much trouble these days and their populations seemingly in steep decline, native pollinators such as bumble bees, carpenter bees, syrphid flies, butterflies and so forth are all the more important. In some ways, I feel like my asters gathered all of these important insects together to reassure me that diversity and flexibility is the name of the game, at least in nature.

The Flying Confetti Garden, Part III

Syrphid flower flies, jet-winged skippers, little bees with full pollen loads, graceful painted ladies, even black and yellow garden spiders.... That's a good start, but there are many more insects hovering around these seemingly magnetic purple blossoms on the asters.

As the butterflies swirl off the flowers and around me, obviously the painted ladies are not the only butterflies that I see. Here is a black swallowtail who came to nectar this fall, showing obvious signs of having lived a long and adventurous life. Notice how worn out his wings are, almost transparent, and how he has lost one of his beautiful swallowtails.

Sometimes I don't see the actual insect that used the asters, just the remnant that shows me it was there. This shed cicada case is a perfect example. Of course, the cicada wasn't drawn to the aster blooms, just to the stems that it could cling to overnight as it made its final metamorphosis from a digging, underground nymph to a clearwinged, flying adult.

Another insect that probably wasn't drawn to the flowers (or at least not to their nectar) is this katydid, perched jauntily on top of the aster. Katydids eat vegetation, sometimes including the petals and buds of flowers, but they are rarely considered pests like many of the short-horned grasshoppers are.
There is one more pair of insects that I noticed on the asters, but they deserve a post all of their own....

The Flying Confetti Garden, Part II

Continuing on with my enjoyment of all the insect life drawn to my aromatic asters (Aster oblongifolius) this fall, the most obvious insects that I see on the vivid purple flowers are the butterflies. As I walk by, it's their drifting flight that swirls around me and brightens the very air I'm passing through.

While I've seen several different butterfly species drawn to the asters, the most common butterflies I see nectaring on these flowers are the painted ladies. It's not uncommon for my 3' diameter aster to have a dozen or more painted ladies on it at any one time.

Apparently painted ladies live on five different continents, making them the most widespread butterfly on Earth. They can't survive freezing temperatures, so the only adults to live through the winter months are those in the south. In the spring, they migrate northward, occasionally even outpacing the monarchs!

Not surprisingly given their large distribution, the hairy/spiny caterpillars of the painted ladies are generalists, eating thistles, mallows such as hollyhocks, legumes and other plants. Occasionally they occur in such numbers that they become noticed as pests. (I doubt, though, that most people able to identify the caterpillars as painted ladies would be quick to destroy them, even if their hollyhock leaves were getting eaten to a nub.)

As these colorful butterflies descend on my asters, I can easily watch the "ladies" daintily unfurl their tightly rolled tongues and sip nectar elegantly through their straws...

and sometimes I have to witness the end of their graceful lives.
Funny, when the black & yellow garden spider catches and eats a grasshopper or wasp, she seems like a heroine, but when she captures and eats a painted lady, her reputation as a villainess jumps immediately to mind.

No matter what she's eating, the black and yellow garden spider is gaining protein for her eggs, next year's black & yellow garden spiders. Hopefully her prey, the graceful painted lady, has already left progeny to give us next year's painted ladies too. Nature's balance is often difficult to watch objectively, but it's worked for millenia. For our own good, we might be a little less quick to judge and a little slower to interfere in the balance of life.

Tuesday, October 28, 2008

The Flying Confetti Garden, Part I

The asters have been beautiful in my front garden this year. First the New England asters (Aster novae-angliae) bloomed, joined soon after by the little bargain-bin Lowe's asters (Aster x) that I got for 50 cents last year and stuck in just to see if they'd make it. Just as all of those were beginning to fade, one of the aromatic asters (Aster oblongifolius) started in, and as it hit full bloom, it was joined by the second aromatic aster, which is only now beginning to dim. Looking back over my photos, I've had almost 2 months of aster blooms this fall.

Almost more spectacular than the asters themselves are the insects that are attracted to their blooms. For weeks now when I walk by the asters, a cloud of butterflies and other insects flies into the air, then settles back down again. I feel like I'm surrounded by brightly colored, living confetti!

About 3 weeks ago I spent several hours trying to capture close-up shots of the insects feeding on the aromatic asters. Here are a few of them....

This little bee has full pollen baskets, although she seems to be busily collecting even more to pack in. It always gives me a little thrill to see the pollen baskets on the hind legs of bees. I have no idea why, but I love them. (For scale, the blooms in all of these photos are actually about 1" in diameter.)

To the right is a syrphid fly. These little guys are colored to look like bees or wasps, but they have no stingers and can cause no harm to humans. The adults feed at the flowers, while the larvae are great predators on aphids, making this a very beneficial insect to find in your garden.

I think this little bee to the left is a leafcutter bee, although I'm not completely sure. If I'm right, this is the insect that cuts circular shaped pieces of leaf from roses, green ash and others. It uses the pieces of leaves to line its nest cells. The cells are packed with pollen and nectar and a single egg is laid in each cell. The insect overwinters as a pupa in its cell and emerges in the spring. There is one generation per year. Leafcutter bees do generally cosmetic damage to some leaves, but are important pollinators - a function that is increasingly important as honeybee populations continue to decline.
To the right is a skipper, a common relative of moths and butterflies that rarely seems to get noticed. If you look carefully, you can see the straw-like mouth coming out of the front of the head and curving down into the flower. This species always carries its wings in this "power jet" formation.
I have many more photos of insects from this aster, but time is running away from me for now, so I'll have to add more later.

The Big Freeze Has Arrived

As I write, the ground is covered in silvery frost, the green leaves of the perennials are looking bruised, and the water in the buckets is covered with a not-so-thin layer of ice. It's 29 degrees F. on the breezeway. The first hard freeze of fall has come.

I'm ready. I've enjoyed being out in the garden and the prairie tremendously over the spring, summer and early fall, but I'm beginning to crave cozy days inside, watching the birds through the kitchen window.

I still have a few outdoor projects to finish before I feel like I've put the yard "to bed", so to speak. There are about 100 daffodil bulbs, 100 crocus bulbs, and 20 tulip bulbs sitting on my kitchen counter that need to be planted. I need to harvest the sweet potatoes (if the cotton hispid rats and voles have left me any). I need to do a final weeding, to catch the winter weeds that have suddenly sprung up in the last couple weeks. Last of all, when people start raking their yards, I need to gather leaves, chop them, and put another layer of mulch on the flower beds.

Meanwhile, the first white crowned sparrows and Harris sparrows have shown up in the last week, the green ash have completely lost their leaves, and the natural world is glowing gold with tinges of orange. "It's a most wonderful time of the year."

Saturday, October 18, 2008

Exploring the Salt Mines

Normally I seek out sunlight and green, growing things, but every once in a while circumstances take me in the opposite direction. Today was one of those days.

With a group of friends from Clearwater, Prairiewolf and I visited the Underground Salt Mine Museum in Hutchinson. It's only been open for about a year and, like so many locals with their own area tourist sites, we hadn't been to see it yet.

After a slightly daunting safety film, we gathered our courage, geared up and headed down in the hoist. The tour guide was knowledgeable and humorous, while the mine itself was spacious and amazingly pleasant - cool and even temperatures, moderate humidity, and fresh-smelling air. The walls even glittered as the lights reflected off the salt crystals in them!
After a trolley tour during which the guide pointed out geological features, remnants of mining activity from the '30's and '40's, and a variety of features of the mine, we went on a self-guided walking tour, examining the mining equipment, watching videos about the mining process, and learning about some of the interesting items now stored in the hollowed out mining galleries.

Coming back out of the mines, the thought we all seemed to experience at once was disbelief at the amount of activity occurring deep below the seemingly undisturbed surface we were driving over.

There was much more to see than I'd realized, and it was a fun and informative adventure. If you're ever nearby, I'd recommend taking a couple hours to check it out. You'll never look at road salt and table salt in quite the same way again!

Suddenly Seasonal

We left for a weekend trip to San Antonio last weekend and were gone for 4 days. It was late summer when we left...and fall when we returned.

The green ash trees had gone from "streaks" of yellow in their green canopies to "streaks" of green in their yellow canopies. Seemingly overnight, many of the honeylocusts had simply changed with no prior notice, also from green to yellow.

The weather had gone from the mid-80's, requiring the air conditioner, to the mid 50's, requiring the furnace.

Most disconcerting was the apparent disappearance of Charlotte, our newly adopted Argiope spider. For a few days before we left, she had refrained from rebuilding her web across our kitchen sliding door, then she moved away from the door to a spot on the siding about 3 feet away. When we got back from our trip, there was no Charlotte to be seen, but there was a brown ball firmly attached to the siding where she'd been hanging out. Her egg sac. Next year's black and gold garden spiders.

I looked for her body but didn't find it, so I decided that a bird had probably eaten her.

Then just 2 days ago, I spied her! She had moved way up to the eaves, more than 2 stories off the ground at that point on our house. I can't see her now unless I go outside and squint upwards, preferably with the binoculars firmly glued to my eyes, but I'm glad she's there. Who knows? Maybe she'll gather enough energy to lay yet another sac of eggs, ensuring even more garden spiders next year.

Meanwhile, each day brings more signs that summer is wrapping up and winter is fast approaching. I love the clear blue skies, crisp air, and bright fall colors, but I'm not 100% sure that I'm ready for winter yet. Ready or not, it's coming. Then, before I know it, I'll be noticing signs of spring. The rapid cycling of the seasons brings bittersweet poignancy to my heart these days, but thankfulness, too, that I'm lucky enough to notice and revel in it.

Wednesday, October 08, 2008

Where the Wild Things Are [Or Should Be]

On Monday night Prairiewolf and I had the opportunity to attend a talk given by Richard Louv, author of Last Child in the Woods: Saving Our Children From Nature Deficit Disorder.

This book has been creating quite a stir in the environmental education community since it was published 3 years ago, so I was vaguely familiar with it. I hadn't, however, read it. Louv's lecture was not only interesting, it encouraged me to pick up his book so that I could delve deeper into his research and findings.,

(Note: I've just started reading the book. Most of the following commentary is based on his talk, his "sermonette" as he called it, and on my concerns and observations.)

Louv has been able to pinpoint a phenomenon that many of us, working with children and nature over the years, have noticed. He's gone further, then, to solidify our growing unease into a coherent theory of a radical change occurring within our culture.

That change, to paraphrase Louv, is the growing alienation of our children from nature.

The need of most children to play outside has basically been an accepted part of childhood throughout human history. In fact, for most of human history, all of us, adults and children, spent a great majority of our time outdoors, interacting with the natural world.

It's been such an accepted part of human behavior that no one has thought to study it...or has even thought much about it at all. Until suddenly it's not occurring anymore.

It's still not studied a great deal, for the simple reason that no one stands to make a great deal of money out of proving that children - or any of us - need to be out in nature. However, the studies that are being done show that free play in natural settings not only develops physical muscles, it also develops creativity. Free time in nature helps children deal with stress and helps them learn self sufficiency. Perhaps most important of all, it grounds them to the natural world in a deeply satisfying way that serves to nurture them throughout their lives.

While they may learn facts and interesting information, often about large animals halfway around the world, watching nature on TV is ultimately alienating if it is your primary exposure to the natural world. It sets nature off as "other". Watching a tree's limbs wave on a screen is very different from being up in that same tree, hearing the wind rustle the leaves around you, feeling it ruffle your hair while the branch below you sways as you look out over the surrounding landscape from your hideout deep in the middle of that tree canopy.

Louv has all sorts of data from various studies to back up his concern and his hypothesis, but those of us who have been lucky enough to experience this free exposure to nature in our childhoods can viscerally sense the loss to children who are unable to have these same sorts of experiences.

One other point that I think is very important to make.... It's tempting to point the finger at TV and other electronic devices as the culprits, or even to vilify the children themselves for being too lazy to get up off the couch or floor and go outside, but the problems are much more multi-faceted than that. Where are the children supposed to go play if they do go outside? Our yards are sterile and there is almost no open space left free around our cities. Our litiginous society makes us scared to let other people's children play on our property, and our overblown fear of strangers kidnapping our children makes us afraid to let them out of our sight. We've become dangerously scared of "germs" and "bugs", to the point where we're willing to poison ourselves in a vain attempt to delete natural bacteria, insect and spider populations from our lives. We're even scared to let our children get dirty because "people" might think we're bad parents!

We live in a free country, but we're caging ourselves and our children in a vain attempt to make life "safe" and we're impoverishing ourselves and them in the process. (Of course, that opens many discussion areas beyond this, but I'll save those for another time.)

Even if you can't take the time to pick up Louv's book and read it, I urge you to look around you with the thought of where you would play if you were a child. I think a connection to the wild ultimately makes each of us a little more human.

Friday, October 03, 2008

Spider vs. Wheel Bug: Battle of the Predators

Not that there was much battle about it. Charlotte won, "hands" down! The wheel bug was still alive and literally kicking when I took this photo, but she didn't last long.

Charlotte feasted on her for at least 24 hours, after moving her back to the center of the web.

The interlocking strands of the web of life fascinate me, especially when I get to observe them firsthand...and literally. Why would anyone simply kill off any bugs and spiders they see, rather than get to watch all of this real-life drama right under their nose?

A Bold, Beautiful, Benign Brand of Spider

As I was trying to learn the exact species name for "Charlotte," I came across some other interesting and fun facts that I thought I'd share.

As a starting point, I'd recognized her as a black and gold garden spider (the common name I knew) in the genus Argiope. As I understood it, Argiope spiders were the ones who wove the zigzag pattern into their webs. I was also quite sure that she was female, based on her size and the relative rotundity of her abdomen.

As is often the case, things were a little more complicated than that.

Charlotte is indeed female. She is an Argiope aurantia, also known commonly as the black and yellow garden spider, the writing spider, the yellow garden spider, the corn spider, and a lot of other similar names. These spiders are common around gardens, homes, and open, sunny areas in much of the U.S.

Males of this species (and many other spider species) are much smaller and more slender than the females. In this species, the male finds his way to a female's web at about this time of year. There he lurks around the perimeter, sometimes building a smaller web on the outskirts of the female's web or just nearby. He carefully plucks and vibrates the female's web, ready to make a run for it if necessary, to let her know he's there. After mating, the male usually dies or sometimes is eaten by the female for the extra protein to supply her eggs.
The female then constructs from 1-3 egg sacs of brown silk, each about 1" in diamater with a narrow neck and containing from 300-1400 eggs, which she suspends near the center of her web. She protects the egg sac(s) as long as she is alive, but she will die with the first frost. The eggs hatch that same fall, but the spiderlings remain dormant in the sac until spring, when they exit their sac and disperse. There is one generation per year.

Believe it or not, the bright yellow and black coloring of these spiders actually serves as camouflage in the open, sunlit areas where they usually build their webs.

Black and yellow garden spiders are neat housekeepers, rebuilding the center of their web every night. Actually, when I saw her, Charlotte was working on her web in the early morning hours, just as the sun was coming up. It was fascinating to watch the reconstruction work. As you can see in the photo to the left, first she ate the old web strands, then she would spin the new. Just in the short time I watched, I noted her producing 3 different kinds of silk: the sticky single strand used to make the spiral, a fine strand (presumably not sticky) that makes the cloudy center of the web (the part she's eating in the photo), and a heavy multi-strand silk used to make the zigzag pattern. Add to those the heavier nonsticky strands used to construct the radials and the strands used to make the egg sacs, and Argiope aurantia produces at least 5 distinctly separate types of silk.

Each web has a "free zone" between the central hub and the sticky catching spiral. With only the non-sticky radial lines in this area, the spider is free to move back and forth from one side of the web to the other through this area.

The zigzag pattern woven into the web is called the stabilimentum and is a common feature in the webs of spiders who leave their webs up during the day. At least 78 species of spiders build similar structures in their webs. Since webs with a stabilimentum catch as many as 34% fewer insects than those without, it is thought to be a warning to birds to help them avoid flying through the web and ruining it. Another theory is that it serves as further camouflage for the waiting spider.

Black and yellow garden spiders are important predators on grasshoppers, among other flying insect species. They can catch and eat insects up to twice their own size in their webs.

At the same time, they themselves are eaten by wasps, birds, lizards, and shrews. Their egg sacs are also preyed upon by many other animals, including birds. In fact, one source reported a study showing that 19 species of insects and 11 species of spiders besides A. aurantia emerged from A. aurantia egg sacs.

Last, but certainly not least, black and yellow garden spiders are considered generally harmless to humans. They are very gentle, only biting upon extreme provocation. Their bite usually produces an area of sore, itching swelling that subsides after a couple days. (Note: Individual reactions to any insect or arachnid bite may vary due to individual sensitivity. I would hardly recommending provoking any spider into biting, if it all possible!)

This is a fun type of spider to watch during late summer and fall, when they are the most easily noticed, although not everybody is lucky enough to have their own Charlotte hanging just outside their kitchen door!