Thursday, September 30, 2010

Arachnophilia

You could say I have arachnophilia, an affection for spiders. Instead of running screaming from a room where a spider has made an appearance, I will readily scoop one up that is in harms way and take it to a safer spot.


So, I was quite pleased to come across this beauty, a lovely Banded Garden Spider, Argiope trifasciata. The name "banded" comes from the tri-colored (yellow, black and white) stripes on its dorsal side, or top, of the abdomen. Trifasciata means three banded, with the root fasciatus meaning "enveloped in bands". My recent shots from that angle did not turn out, but you can view another one at a previous post here.

I enjoyed watching its acrobatic antics as it swung across its decimated web. I was not sure if one of our party had accidentally destroyed the web, or if it had happened at another time. The spider was starting to rebuild.

This belly shot shows the spinneret, the organ used to spin its elaborate web. (It is right under the black marking in the middle of the abdomen.) If you look closely, you can see the silk coming from the opening. Argiopes are orb weavers that construct the beautiful webs with the spoke-like patterns. To see one of these webs bejeweled with dew in the early morning is utterly breathtaking.



Above is a closeup of the spinnerets. Each species of spider has between 2 to 8 spinnerets that are usually in pairs. The spinnerets are comprised of hundreds of glands that produce different types of silk. A spider will spin different types of silk depending on the job and can control each gland to produce silks of varying components. The silk is a liquid solution that is pushed through long ducts that lead to microscopic spigots. It can control these spigots to produce a silk with varying amounts of stickiness and strength. Also, each spigot has a valve that regulates the thickness of the silk and the speed it is deposited. The spinneret will wind the individual strands of silk fibers together to form the different types of silk.


Above is an amazing shot of the spigots from an electron microscope, magnified 1,500 times. This shot courtesy of MicroAngela. It show the multiple spigots that comprise the spinnerets. By examining the photo, one can somewhat understand how the spider spins silk with varying strengths and stickiness. In the same way that yarn is comprised of individual fibers that are wound together, the spider's silk is made by winding various strands of silk fibers together. If grandma wants to make a hat, she will choose various lengths, textures and colors of yarn that she will use to knit the hat. In the same way, the spider can take various silk fibers, some that are sticky, some that are stronger, some that might be thicker, to produce a product it can use for the task at hand. If it wants super strong silk for its egg case, it might use stronger, thicker fibers. If it needs super sticky fibers for the center of its web, it can produce those, as well.

If one spends a little time learning how awesome and amazing spiders really are, I think less people would be afraid of these small industrious creatures!

StumbleUpon

Tuesday, September 28, 2010

I'm Blue

Hearing the song "I'm Blue" made me think of the many blue flowers that are blooming right about now.

One of my favorites is Closed Bottle Gentian, Gentiana andrewsii. This beauty has blossoms that are always closed, making it look like it is perpetually in bud. Pollinated by bumblebees, one was caught in the act.


Blue Mistflower, Conoclinium coelestinum, for some reason reminds me of cotton candy. Its delicate feathery flowers are a lovely shade of periwinkle.

Great Blue Lobelia, Lobelia siphilitica, is a relative to the lovely cardinal flower. One of my friends was lucky enough to witness a Giant Swallowtail butterfly nectaring on it.

So, how could one stay blue seeing all the beautiful flowers that are out and about? Go outside and enjoy this awesome weather!


StumbleUpon

Sunday, September 26, 2010

Some Smug Slug

Rolling over a log while on a trek with friends, revealed this critter. A huge Leopard Slug, Limax maximus. Since I didn't know a whole lot about Leopard slugs, I did a little sleuthing on the internet. Wow! There are some really cool things to learn about these slimy creatures. I found out Leopard Slugs are not native to the United States. They were introduced from Europe.



I knew they had a organ used for eating called a radula which is like a tongue with raised chitinous teeth. These teeth scrape up bits of vegetation and a thick saliva transports it to the esophagus.

Radula of snail/slug. Drawing from Wikipedia


Slugs breath through a special apparatus called a pneumostome. It is an opening on the right side of the slug where air enters into the slug's single lung. Slugs are placed in family groups based on the location of the pneumostome on the slug's body.

Slugs also have an amazing mating ritual. This could be right out of a sci-fi movie. It is fascinating and actually beautiful, in a weird sort of way. I really could not do it justice by describing it, so I will let the master, David Attenborough, describe it for you in this video clip from Life in the Undergrowth.


StumbleUpon

Friday, September 24, 2010

Goldenrod Ninjas

Goldenrods are blooming in abundance at our park. Their brilliant yellow flowers are irresistible to many insects, especially the butterflies.


Delicate and dainty, Pearl Crescents, Phyciodes tharos, were numerous, flittering about on Riddell's Goldenrod, Oligoneuron riddellii.


Common Buckeyes, Junonia coenia, were also enjoying the abundant nectar from the goldenrods. Usually flighty. this one let me sneak up fairly close for a shot before it took off.

When butterflies and other insects are slurping up nectar, they tend to not pay attention to potential dangers that lurk around them. This nearby plant looks fairly safe at first glance.


But the view from the other side tells a different story. Yep, a hungry Praying Mantis lies in wait for an insect to land. Scroll back up to the prior picture and see if you can spot its abdomen, which looks similar to a dead leaf.

The Stiff Goldenrod, Oligoneuron rigidum, in our butterfly garden also had hidden horrors. This gray, dead "leaf" is actually the abdomen of a Wheel Bug, Arilus cristatus. It flew away before I got a decent shot, but you can see a better photo at a previous post. This armored insect grasps its prey and inserts a huge needle-like stylet into the insect, fills it full of paralyzing enzymes that digest the prey's innards, then slurps it up like a yummy bug milkshake. Mmmm good!

But the Praying Mantis and Wheel Bug are not the masters of camouflage. There is one bug that truly rules the goldenrod patch. A goldenrod ninja lurks among the blossoms...

Looking like a dead flower head, the cropped picture reveals the stealthy predator. A Jagged Ambush Bug, Phymata pennsylvanica, is concealed from unsuspecting nectar seekers.

Checking another flower, the small brown patch on the right side of the flower is another Ambush Bug.

By tipping the flower, this angle shows the mini-ninja. But don't be fooled by its tiny size...

Here's one with a small bee which looks like the appropriate size meal for this critter. But wait, there's more. Just like the Wheel Bug, the Ambush Bug also has crippling enzymes in its arsenal of tricks. Faster than lightening, the Ambush bug will grab a bug with its thick front legs and zap it with powerful enzymes that immobilize much larger prey. And many times, they do it while mating! Talk about multi-tasking! This photo from BugGuide shows two little Ambush Bugs mating and dining on a huge BALD-FACED HORNET! Yikes!

Impressive skills, ninja warrior, very impressive!StumbleUpon

Thursday, September 23, 2010

Albino Hummingbird in Indiana

A pretty cool looking hummingbird has been seen in Vigo County, Indiana, near Terre Haute. It is a true albino Ruby-throated hummingbird, which means it does not have any pigment on the body. The feathers are completely white and the eye is red. I do not have any photos of the bird, but here are links to Marty Jones's photos and Jim Sullivan's photos. (There recently was another white hummingbird, a leucistic one, that showed up in St. Louisville, Ohio this month. You can read about it here at Jim McCormac's blog and he has a nice explanation of leucism vs. albinism.)

Albino hummingbirds, although very beautiful, sadly do not survive. There are a couple of reasons. Allen Chartier, a fairly well-known hummingbird bander from Michigan, had some interesting comments on IN-bird , the Indiana Birds listserv, about albino hummingbirds and their survival. A hummingbird researcher in Oklahoma has been tracking albino hummingbirds. Of the banded ones, there have been no returnees. There, of course, is the obvious predation factor. A bright white hummingbird will stand out like a sore thumb to most predators. But Allen gave another reason I did not realize. According to Allen "it has also been proposed that these albino hummingbirds might not complete their migration as flight feathers lacking pigment are not as strong as normally colored ones, and so might wear out much faster, possibly even before the bird reaches its wintering grounds. They cannot force themselves to molt these worn feathers, as molt is driven by hormonal changes triggered by changing day length."

Interesting information, Allen!StumbleUpon

Tuesday, September 14, 2010

Awwww! Look at the Baby!

Today we were conducting a little pond exploration and found the cutest little baby turtle.

Not much bigger than a quarter, this little cutie will pack a punch when it gets a bit older. The common name is Stinkpot or Common Musk Turtle, Sternotherus odoratus, because when they are disturbed they tend to give off a scent similar to a skunk's "perfume". If you would like to see one that is a little bigger, you can check out a post I had earlier this summer.StumbleUpon