Friday, September 28, 2012

Zebra Longwings

I took this picture of a Zebra Longwing butterfly at Paynes Prairie Preserve State Park the other day.
Zebra Longwing on Bidens alba
Zebra Longwings (or Heliconians) are the Florida State Butterfly. I grew up in Utah and had never seen one until I moved to Florida. They're beautiful and photogenic butterflies, with their black and white zebra stripes, red spots and blue compound eyes. And they do indeed have long wings. They're gentle, slow fliers that waft through the landscape. They are (usually) fairly common and stick around late into the fall. But last year they were completely absent, all year. We had an extremely harsh winter in 2010-11, with record cold temperatures. We had 27 days of below freezing temperatures, which may sound like no big deal for someone in the northern climes, but down here in the subtropics, the weather killed our landscape plants. In South Florida the iguanas were dropping out of the trees (which was probably a good thing--more on that another time!). The Zebras are not cold hardy, so their populations froze back to South Florida, where the winters weren't quite so cold. I never knew how much I had come to love them until they didn't appear. No one was sure how long it would take for the Zebras get back north. One person I talked to said it could be years. This past winter was cold again, but not as bad as the year before. Early in the spring, my husband and I took a trip to Miami. We saw Zebra Longwings all over the place and it was so nice to see them again. It made me sad to think that we wouldn't be seeing them in Gainesville for a long time. So you can imagine my reaction when I saw a couple at our botanical garden in early summer. The Zebra Longwings returned! Over the summer I saw more and more, and now I feel like the population is about back to normal. In fact, I just saw one drift past our dining room window. What a relief!

Zebra Longwings are cool butterflies. As I mentioned, they are primarily a tropical or subtropical species, so are not cold hardy. But they are fairly long lived, as far as butterflies go. They can live for several months, as opposed to weeks, because they eat pollen along with the nectar from flowers--a very unusual butterfly behavior. Their host plant is Passion Flower (Passiflora sp.). The Gulf Fritillary also uses Passion Flower as a host plant, but (this is so cool!) Zebras lay their eggs in the shade, and Fritillaries lay theirs in the sun. We had a big passion flower vine in the yard of our previous house and I watched this in action. The two types of butterflies would segregate their populations between the shady and sunny places in the yard. The females lay their geometric looking eggs on the tips of the new leaves, and soon the tiny white and black caterpillars emerge.
Zebra Longwing Caterpillar

When they finally pupate, the chrysalis looks just like the dried leaf of a passion vine. They blend in perfectly. The chrysalis is beautiful, with numerous irridescent patches that look like jewels or stained glass windows.
Zebra Longwing Chrysalis

Zebra Longwings engage in something called "pupal mating". As a human, I find this rather repulsive. But in biological and evolutionary terms, it makes great sense, because it provides a better chance that the first male's genes will be passed on. Males will crowd around a chrysalis where the new female butterfly is almost ready to emerge. They fight to be the first to mate with her, thus ensuring that their semen is first to fertilize her eggs. Sometimes the males will mate with her before she's emerged from the chrysalis. The first time I saw this, I had no idea what was happening. I thought the emerging butterfly was in distress and the nice butterfly friends were helping it out. Then I read up on Longwings and discovered what was really happening!
Attentive Male and Chrysalis

One other interesting behavior is roosting. Groups of Longwings will gather together at night to keep warm. They don't do it on the scale of Monarchs overwintering in Mexico, but they can sometimes form fairly large bunches. We had a Lepidoptera graduate student watching roosting Zebra Longwings in our yard to understand what chemical cues they use to return to the same spot.
Blurry picture of Roosting Zebra Longwings
So you can see that I'm a fan of the Zebra Longwing. I'm glad they have returned and will look forward to watching them well into the fall.

Tuesday, September 25, 2012

What's Eating Me

I was going to write all about blood sucking arthropods this week. I'm one of those special people who attracts every kind of biting organism. Mosquitoes swarm me. No see 'ums see me. Fire ants used to make me get welts the size of a dinner plate, but now I'm used to them, so I just get the itchy bite with the nasty little pus cone (if you've been bit by them you know what I mean). If there's a tick anywhere nearby it will find me. Chiggers bit me all over just the other day when I was taking the owl/hawk/crow pictures. DEET doesn't help. Recently, we adopted a cute stray kitten. He's a good little guy, but he was infested with fleas. And now we have fleas in the house and I have bites all over my ankles. Between the mosquitoes, ticks, chiggers and fleas, I look like I've got measles. I hate the lot of them.

But I got a reminder today that it could be much, much worse.  I was out at the Natural Area Teaching Lab at the University of Florida hunting for good caterpillar and butterfly photos and saw something large and strange trundling along the top of a fence. When I went to investigate, I understood why it looked so strange. It was a Pine Sphinx Moth caterpillar, almost unrecognizable under the bulk of scores of Braconid Wasp cocoons. Fully grown, a Pine Sphinx Moth caterpillar will be the size of my pointer finger. They are pretty cool looking, with long white/yellow stripes, white speckles and large black ringed spiracles (breathing holes) along their sides. This one had been parasitized by a Brachonid Wasp. Braconids lay their eggs inside their hosts. In this case, just under the skin of the large caterpillar. The eggs hatch and the larvae eat the caterpillar from the inside but don't kill it right away. The caterpillar is dying slowly and probably doesn't know it. When the wasp larvae have matured, they bore holes through the caterpillar's skin and make a cocoon. They pupate as they ride around on the caterpillar. Then the wasps emerge as adults and the caterpillar dies soon after. Kind of a horrible way to go, I think. Gardeners and farmers use Braconid Wasps as biological pest control agents in organic gardens. Caterpillars are major crop pests--think tomato horn worms, for example. I guess it's better than pesticides, but it's no fun for the caterpillar. On the other hand, it's great for the wasps.

Pine Sphinx Moth with Brachonid Wasp Cocoons
So, for now I'll just be remind myself that itching is one thing, but being eaten from the inside by larvae is another. Of course, there is always West Nile Virus and Lyme Disease, as well as other horrible insect borne ailments, so I'll have to be work harder at my mosquito and tick bite prevention. But at least I'll never be covered with cocoons.

Sunday, September 23, 2012


Today I took a walk around my favorite city nature park, Morningside Nature Center. I love it because it's a patch of sanctuary in our growing city. I can always be sure to see something special when I visit. I worked there as part of the teaching staff for several years and got to know it quite well. It is a special place and I try to go there often.

As I was walking along the new boardwalk in the Cypress Dome (it's beautiful and FULL of water for the first time in many years) I decided to focus my attention on listening. Weekends are really quiet there and I was one of about 3 people in the park, so I could hear tiny sounds and sounds from far away. Around the Cypress Swamp, the primary sound was buzzing. The cicadas buzzed from the treetops and the mosquitoes buzzed in the shade. I could hear the buzz and plop of the dragonflies dipping and laying eggs. I heard leaves drop into the water. A frog chirped from somewhere in the trees. Another plopped into the water. Soon I became aware of bird sounds and was happy that over the years I'd learned to identify a few of their calls. I'm not a super birder, but I'm enthusiastic and do know some of the calls. I tend to walk with my head down, looking at flowers and bugs, so if I hear a bird call that I recognize, it at least points my head in the right direction. Today I could hear the squeaky rubber ducky sound of the Brown Headed Nuthatches. Next I heard the White Eyed Vireo. Sometimes it sounds to me like it's saying "chick" followed by a gobbledegook. Other times is sounds like it's saying "Step to the rear, Jack" ("Or give me a beer, Jack"). In the bushes next to the walkway I could hear the Eastern Towhees calling "Shweep, Drink your teeeeeeeeea". When I hear tapping, I look for woodpeckers, but sometimes if it's a tiny tap, like today, I find that it's a Tufted Titmouse standing on a branch cracking open a seed. Listening opens my eyes.

After a bit, I heard a commotion. A bunch of crows. They were loud and calling from across the park. I thought there was a chance that they were mobbing an owl, so I followed the sounds. Crows dislike owls and will gang up on them to chase them away. Mobbing can be very effective and smaller birds like crows and bluejays can chase away a much larger predator or competitor. I once watched a single, tenacious mockingbird bother a great horned owl so much that it finally flew away. When I got to the source of the racket, I was happy to find that it was indeed an owl. A great horned owl was perched on a pine tree and a flock of crows surrounded it from the trees, cawing and diving at it.

Crow trying to intimidate a Great Horned Owl
This time, the mobbing did not work and the owl just sat there.

This Owl Ain't Budging!
Other kinds of birds were chattering in the trees. Everyone was upset about this intruder! I heard mockingbirds and bluejays. Then I heard the sound of a red shouldered hawk. I thought that it could just be bluejay mimicking a hawk. They actually do a pretty convincing impersonation. I've watched a bluejay clear the bird feeder out with a well placed call. But this time, it was real, and a red shouldered hawk flew into the tree to join the mob. I imagine that the crows, jays and mockingbirds weren't sure what side to take. They don't like hawks, either, for the same reasons that they don't like owls, and can often be seen mobbing them. (The bluejays and mockingbirds will mob crows for the same reasons as the hawks and owls, so this gets really complicated.) So when the hawk moved in, the rest of the birds quieted down and watched from the trees.

Hawk/Owl Stare-Off

Red Shouldered Hawk tries to scare the Great Horned Owl
The hawk repeatedly flew at the owl and tried to knock it off its perch. I heard the "thwack" of the hits. But the owl wouldn't budge. Then the hawk tried flying right in the face of the owl and spreading its wings to look bigger and more frightening. The owl stayed put. I watched the hawk go back and forth from one branch to another, flapping its wings, calling and flying at the owl. Finally the hawk flew away to pine trees nearby. I could hear it call. I'd been watching for about 20 minutes and my arms were tired from holding the camera, so I walked away. Of course, as soon as I was out of sight, the crows started up again. This time they were loud and furious, and I saw some commotion from the trees, so I think they were finally successful. I don't know for sure because I didn't see it, but the silence that followed spoke volumes.

Sunday, September 16, 2012

And So it Goes...

A couple of nights ago my husband and I were walking our dogs when I saw something moving on the sidewalk ahead of us. As we got closer we could see that it was a big Golden Orb Weaver Spider (aka "banana spider") and some sort of large wasp. The wasp flew off too fast for me to identify it. I think I saw some red, but it was dusk and it all happened too quickly for me to really see it. I thought that if we waited for a minute, the wasp would come back. I suspected from the color and behavior that it was a Mud Dauber wasp. These are the harmless (unless you're a spider) wasps that build those tubelike mud structures on our houses. Mud Daubers paralyze spiders to feed to their young. They pack the spiders into their mud nests and lay eggs inside. The spiders are there, alive but immobile, serving as fresh food for the newly hatched spiderlings. So, getting back to the spider, it made sense that the flying insect was a Mud Dauber. However, what didn't make sense was that the spider was too big for any wasp to carry anywhere. We waited for a few minutes, but the wasp didn't return. So we continued on our walk.

I didn't have my camera with me, so when we got home again I decided to go back and take some pictures. I figured that the wasp may go back and try to drag the spider away. I've seen wasps dragging some pretty big caterpillars, so why not? It took me a few minutes to find it, but when I got to the spot, the spider was still there, but no sign of the wasp. It made me a little sad. The big spider was so beautiful lying on the sidewalk with its hairy legs and elaborately painted abdomen. The legspan on this one was probably 3 inches. These are truly glorious creatures.
Golden Orbweaver Spider
As I looked at the spider more carefully, there were signs that it was dead and not just paralyzed. There was a puddle of something next to the spider, and as I looked closer, I could see ants underneath it, working furiously. I could see that there was a hole in the upper part of the abdomen. This spider was definitely dead. Maybe the wasp was a red herring. Something else could have killed the spider and the wasp was just passing by. Or maybe the wasp bit off more than it could chew and just gave up. I'll never know. In any case, the ants had discovered the spider and were making quick work of it.
Definitely Dead, With Ants Underneath.
The next morning I came back again to the spider to see how far the ants had come with their disassembling. The ants had been very busy. The spiders legs were still there, but the abdomen was flat and deflated. There was a liquid substance on the ground all around the spider's body. I suspect that the ants had emptied the contents of the abdomen because there were no shoe tread marks  and the rest of the spider was in place.
Next Morning
This morning I went back one last time, hoping to track the ants' progress. I was a little doubtful that I'd see anything because it rained yesterday afternoon. Also, the spider was on a sidewalk and could easily have been stepped on or swept away. But it was still there. It took me a few minutes to find it this time because there was almost no sign of the spider, only the dried up abdomen exoskeleton and some spider residue. The abdomen could easily have been mistaken for a piece of leaf along with other debris from the trees. There were no legs and no other signs of what had happened such a short time before. Just a shiny smear and a few meticulous ants scouring for crumbs. And so it goes...
Day Three. Note abdomen in upper left corner.

Thursday, September 13, 2012

Everyone Loves Bidens

Spanish Needles (Bidens alba)
I talk with people a lot about butterflies and gardens and I'm often asked what flowers are best for attracting butterflies to your yard. There are any number of beautiful plants available that will do the job--milkweed brings in the monarchs and pentas and butterfly bush are also excellent. If you have a wide selection of plants that will provide nectar and a food source for the caterpillars, the butterflies will come. But over the years I've come to believe that the very best plant, one that will bring more butterflies than any other plant I know of, is also one that I won't let grow in my yard. Spanish Needles, or Bidens alba is a pretty native plant that grows in disturbed sites just about everywhere. It is covered with lovely, daisy-like white flowers with a yellow center. Just about every small critter loves this plant, either for the nectar, the leaves or to hunt the nectar and leaf lovers. Butterflies, moths, flies, bees and beetles go for the nectar. Birds eat the seeds. Caterpillars and grasshoppers eat the leaves. Lizards hide in the green. Spiders hunt from the shadows. A perfect, beautiful plant for any butterfly garden, right? Not quite.  Each flower produces numerous needle-like seeds (thus the name, Spanish Needles) that stick to your clothes and anything else that brushes by them. They spread like a cold. Every year I'm tempted to let just a tiny patch grow because they're so pretty and attractive. And every year I regret my mistake as I pull Bidens sprouts from every corner of the yard. I'm not an obsessive, tidy gardener. Far from it. But even I have limits. Now, Bidens is perfect for nature parks, fields, roadsides, and other large swaths of property where weed control is no issue. But it just doesn't work so well in my urban, neighborhood setting. So, reluctantly, I've come to this position regarding Bidens--I will love it forever, but from a safe distance.

I wrote this poem to express my conflicted love of Bidens:

Ode to Bidens

Where Bidens grows there is no doubt,
Butterflies will be about.

Its snow-white flowers with yellow dots,
Insects like an awful lot.

Nice green leaves give places to hide for
Beetles or a little spider.

Seeds that spread on wind and air,
On trouser legs, my shirt, my hair.

You're easy to grow, it isn't hard,
But just not in my own front yard.

Wednesday, September 12, 2012

Let it Go

I had an aggravating customer service experience this morning. I left the place feeling really angry. Over and over I imagined all the smart, self righteous things I would have said in my fantasy re-do of the encounter. I got more and more worked up, ready to write letters and get people fired. I was really irritated. Luckily, since it was on my way home, I decided to stop at NATL to take photos of butterflies. This turned out to be the perfect medicine. As soon as I neared the entryway, I heard red shouldered hawks calling to each other from opposite ends of the fields and the cicadas buzzing loudly. I stepped inside the fence and was swept away into a whole new world, far away from irritating clerks. It was overcast, but it was sunny enough that the insects were very active. The paths are lined with Spanish Needles plants (Bidens alba). Besides being quite pretty, Spanish Needles are very attractive to insects (more on that another time!) and these flowers were bustling. I could feel my blood pressure lowering. My muscles relaxed and my mind had a new focus.  My irritation melted away as I was drawn into the brilliant colors and movement.
Green Fly on Bidens

Painted Lady Butterfly on Bidens

Buckeye Butterfly on Bidens
There was a tractor tilling a field near me and the air smelled like cut grass and warm soil. I breathed in that sweet smell and felt content. I continued taking pictures for about an hour. Every so often I'd recall the bad start of my morning and would start to relive the encounter. I could feel myself getting worked up. Then I would breathe in the sweet air and remind myself that I was surrounded by calm and beauty. The birds sang, the dragonflies darted, and the flowers danced in the wind. It was beautiful.

Bees and Bidens

I am slowly realizing that it is up to me whether or not I dwell on the things that bother me--on the unkind words, the hurt, the injustice, the misunderstandings. If I want to, I can think about them so much that they begin to consume me. Or I can let them go. If I choose to dwell on the past, it's so easy to find myself sucked into a vortex of hurt feelings, resentment and anger. I can pick at those wounds and let them bleed any time I choose. It can be hard to break out of the grips of a good sulk. The funny thing about this morning is that it really wasn't a big deal. "In the Big Sea of Life," as my friend Robin used to say, it didn't really matter. But caught up in my feelings, I lost perspective. When I decide not to indulge my negative feelings,  I turn to nature for an attitude readjustment. It's really hard to stay focused on yourself when you are outside, smelling, hearing, feeling and seeing. The feel of the sun or the wind on your skin is like a gentle nudge. Psst. Hey. Wake up. Look around. Come out. The nice thing about being outside when your irritated is that there are too many distractions to stay focused and nurse that anger. I am thankful for all the distractions out there. And I feel a whole lot better.

Viceroy Butterfly

Clematis reticulata Seed Head
Lady Bird Beetle on Partridge Pea (Chamaecrista fasciculata)

Sunday, September 9, 2012

Love Bugs

We're having our annual late season Love Bug wave.  I was out last Friday photographing butterflies in the Pine Flatwoods Preserve and came back to find my car looking like this.

Our car covered with Love Bugs. The other side of the car had just as many.
Every year when the weather in Florida warms up, the Love Bugs reappear. Unlike with other animals, people do not rejoice the return of the love bug. There is no Love Bug festival that I know of. Instead, Love Bugs are generally considered to be an annoyance to be endured and survived. They are particularly attracted to vehicle exhaust and gasoline fumes and therefore are often found around highways and gas stations. Their populations wax and wane from year to year and throughout the season. There are usually two waves, one in the spring and another in the late summer. Some years there are very few Love Bugs. Other years, you'll see huge clouds of them on the roadways and the fronts of cars and trucks are covered with their splatted bodies. Some people go as far as to buy covers ("car bras") for the front of their cars to protect the paint from the corrosive bodies of the Love Bugs. I've never noticed bubbled paint after leaving them on, but I admit that it's hard to scrub them off. Then again, I don't wash the car much, so I'm not one to talk.

So if everyone hates them, why are they called Love Bugs? If you look at the picture below you will understand.

Love Bugs doing their thing
Love Bugs get their name because they are almost always seen mating, joined together, even in flight and while they feed. Once they find a mate, they stay hooked up for 12 hours or more. This creates some awkward conversations when people, especially other people's children, ask what they are doing.

Popular local mythology says that Love Bugs are the result of a diabolical failed experiment at the University of Florida. This is, of course, not true. (Apparently the same rumor exists in other states, such as Texas, about their respective university entomology departments.) Love Bugs are native to Texas and Louisiana and Central America and have only recently (since the 40's) arrived in Florida, which adds credence to the UF conspiracy theory since they're relative newcomers. Also, they are not bugs at all, but are actually variety of March Fly. Birds and other insects don't seem to eat Love Bugs. The same chemicals that cause them to corrode your car's finish also makes them taste bad. But they are good pollinators. At the same time that car owners are cursing as they scrape their cars clean, Love Bugs are busily swarming in fields of flowers. In addition to being attracted to petrochemicals, they are also attracted to flowers. The adults feed on nectar. And when they move from flower to flower, pollen sticks to their hairy bodies. The larvae feed on decaying leaf matter and can be beneficial as decomposers.

Love Bugs on Goldenrod (Solidago sp.)

Love Bugs on Passion Flowers (Passiflora incarnata
I guess that I'm ambivalent on the subject of Love Bugs. The name is funny. They're kind of pretty when you look close--bright red thorax, big black eyes and long black wings. It's interesting that they are always seen mating. I'm glad that they're pollinators. But it certainly is irritating to have to wave them away from my face and mouth, or away from the gas pump when they're swarming. And it remains to be seen if their carcasses are slowly eating my car. How do I love thee? Hmmm.