Friday, August 31, 2012

Yellow Garden Spider



I took one look at you ....and my heart stood still
                                       --------Rogers & Hart

stabilimentum
Our friend Georgia sent this picture of a "banana spider" which is seen frequently in her garden, asking for its real name. In a prevalent and distinctive looking spider such as this we run into many common names. Whether you like Latin names or not, they are necessary to confidently identify a species.

This is Argiope aurantia, the Yellow Garden Spider, and based on its size and full rounded abdomen it is most likely a female. Between three different authoritative sources it carries the common names of writing spider, corn spider, black and yellow garden spider, zipper spider, banana spider, x spider, corn spider, the yellow and black garden spider, the black and yellow argiope, the golden orb weaver, and yellow argiope.  This impressive list demonstates the importance of a scientific Latin name.

The distinctive zigzag web vertically through the web is called a stabilimentum. It is common among the Argiope (Ar-gee-O-pee) spiders but is produced by over 80 spider species.  A. aurantia makes an especially thick stabilimentum. It is called a "writing spider" from an old old folk tale that says if you see your name written on its web you are about to die - but hopefully not before you can submit the video to Youtube. So much for the kind and empathetic writing of Charlotte's Web.

The beautiful circular web A. aurantia builds is temporary, as they eat all but the long foundation webbing every night, spinning a new web for the next day. Some sources feel they may do this to add tiny particles to the webbing which look like food to small insects, drawing them to the web.

The zigzag stabilimentum is especially interesting. It is made of a slightly different webbing which reflects UV light, possibly attracting insects to it. It is important to recall that other species frequently see different light waves. Other biologists believe the stabilimentum is made to strengthen the web, confuse predators or to warn birds not to fly into the web. No one has asked the spider.


The story of a female spider eating the male after mating is a familiar one in many species (see Black Widow blog). The Argiope is different- the male effectively commits suicide by sex. Spiders transfer their sperm to females using their specialized palps which the male inserts into the female. In the case Argiopes, they die right after inserting their second palp, their heart stops beating several minutes later.  This gives a whole new meaning to Rogers and Hart's lyric, "...and my heart stood still."

The second palp remains inserted into the female, effectively plugging the opening and preserving the males genes from contamination from another male. In other words, he makes the ultimate sacrifice to preserve his inheritance.*
The male’s death is also described as an “irreversible seizure” and apparently this takes place to form a kind of “chastity belt” (James 2003*). Once the male Kamikaze has inserted the second palp, he’s stuck, despite what the surrounding males would like. "The other males go berserk, bite into the legs and try to pull him off." Securing himself inside of her also gives the male’s sperm sufficient time to fertilize the eggs. **
Meanwhile the female never gets to enjoy her 1000+ kids.  She makes a round brown egg sac, attaches it to the web and watches over it.  The spiderlings hatch but the first instars remain in the sac over winter while she dies.  They emerge in the spring to spread out into new territory.  I wonder it the thought of raising 1000 kids is what kills her?

*    See this NIH publication.
**  Comprehensive A. aurantia information with references is at this link.

Wednesday, August 29, 2012

Summer Fishfly

Last week's mystery critter is the summer fishfly, Chauliodes pectinicornis, neither a fish or a fly.  Flies are in the order Diptera while fishflies are Megaloptera.  You probably all ready guessed that they aren't fish either.

They fly for around a week looking for the opposite sex and eating little if anything except possibly plant juices.  They lay their eggs near still water and the larvae crawl in an spend a year, possibly more there.  They are carnivores, eating tadpoles, minnows and aquatic insects as well as detritus.  Finally they crawl up on land and find rotten wood to pupate in, emerging in 10 days as adults to start the cycle again.

There are several species of fishflies in the Chauliodesgenus.  This one has prominent pectinate (comb-like) antennae between its eyes.  Notice the delicate mandibles in front of its mouth.

I am calling this a summer fishfly C. pectinicornis, rather than a spring fishfly C. rastricornis based on the Bugguide description.   
"Head and pronotum have yellow markings on dark brown background, compared to dark markings on yellowish background in C. rastricornis"
Fishflies are sensitive to pollution so finding them around Bull Creek is another indicator of stream health.  Although the creek levels are down, there are still a few shallow holes and well as ponds for them to inhabit.

The Bugguide reference has information on rearing fishflies, but I think I will just "leave a light in the window" for mine.
=============================
"I bee a fly"
Coming soon, another unknown.  This one "be a fly," a real fly for a change.  It helps maintain your house, kind of a flying home owners policy against a destructive force of nature.  It may fly slow but it does good work.

Monday, August 27, 2012

Epizootic Hemorrhagic Disease

MDC
When I was a kid, a common phrase to describe your cold or virus was "a case of the epizootic" or "epizootie."  We thought we were being cute, but it isn't a funny phrase any more.  We found another dead deer in the field, making a total of 3 adults and 3 fawns this summer.

Francis Skalicky writes in the News-Leader about the effect of drought on deer, making them increasing susceptible to Epizootic Hemorrhagic Disease (EHD).  Chronic Wasting Disease (CWD) is a neurologic disease which gets a lot of press.  Chronically ill deer which slowly loose weight, act listless and walk around without their usual alert behavior are more likely to attract our attention.

EHD causes defects in blood clotting as well as blood vessel damage.  The resultant internal hemorrhage creates a variety of more rapid symptoms which are indistinguishable from bluetongue disease.
"White-tailed deer develop signs of illness about 7 days after exposure. A constant characteristic of the disease is its sudden onset. Deer initially lose their appetite and fear of man, grow progressively weaker, often salivate excessively, develop a rapid pulse and respiration rate, and fever (affected animals frequent bodies of water to lie in to reduce their body temperature) and finally become unconscious.  Hemorrhage and lack of oxygen in the blood results in a blue appearance of the oral mucosa, hence the name 'bluetongue'. Eight to 36 hours following the onset of observable signs, deer pass into a shock-like state, become prostrate and die."
Culicoides midge
The disease is caused by a virus transmitted by a midge or Culicoides biting fly such as Culicoides variipennis. These vectors occur around muddy water pools and deer are increasingly attracted to these areas during a drought. Outbreaks occur in late summer and fall until freezing temperatures kill off the vectors for the year. The unseasonably warm winter may have contributed to an increased number of midges.

Since the virus dies within 24 hours in the deer's carcass, it doesn't pose a transmission risk.  There is no risk of human disease although no one should harvest a sick deer anyway.

Comprehensive EHD information is available at michigan.gov/dnr.


Saturday, August 25, 2012

Mystery Critter

Several of these flew to our deck light last night, a common behavior for this species which is found around water.  They have pectinate antennae and their mouth parts may be a clue.

The adults live a week, mainly to breed although they may take in plant juices.  Their larvae live a year, possibly longer.

Their  common name  combines two words, neither of which describes this family of animals.

Put your guess in the comment box and look for the answer next week.

Friday, August 24, 2012

Trees Are Like Friends

Bull Creek Valley- Jennifer Ailor
Jennifer Ailor* wrote a beautiful article published in the Springfield News-Leader.  For those outside of the area, I am reprinting it here.

Trees are like friends to local naturalist


Looking out my window into a valley of Mark Twain National Forest, I see a forest dying for a drink. True, our spotty rains have helped some trees, but they all need a Big Gulp.

The occasional brown spot in a canopy of green in my valley has morphed into streaks and clumps of brown trees along the ridge tops and on southern-facing slopes. Walking my tree-shaded lane, I see close up how much they need that drink: limp, droopy leaves on the understory papaws; shriveled, crunchy-looking dogwood leaves; yellowing sycamores. It’s painful to see their stress.

I’ve always been a tree lover. I love their gray bones and intricate barks in winter, delicate greens of spring, welcoming shade of summer and in-your-face fall color.

Growing up in north Missouri, I’d ride my horse, Sparkle, into “the timber,” as we called it, a badly cut-over woodlot. The big woods of “A Girl of the Limberlost” they were not but nevertheless beautiful to me. I’d soak up the trees’ strength and dignity and silence (corny, I know, but they felt almost like sentient beings), taking delight in even the most scraggly, misshapen seedling. 

Sometimes the woods were my escape and comfort when my dad was angry. Come cutting time, it was gut-wrenching to see my friends turned into firewood for our uninsulated old farmhouse.  Today, I feel the same when I see the bodies of trees stacked on big trucks headed for sawmills to be turned into pallets that often end up in landfills — an inglorious end to century-old oaks.

There’s not much we can do to give our Ozarks woods a drink in this dreadful drought. Just too many trees. But we can take care of the young trees struggling in yards and along city streets, giving them enough sips of water to survive until the rains come. These baby trees need a helping hand.

We also can plant trees. If there’s no more room on your property for another tree, then give to organizations that will plant trees for you, such as the Arbor Day Foundation, www.arborday.org, and Plant a Tree USA, www.plantatreeusa.com. Give to organizations like Forest Releaf, www.moreleaf.org, here in Missouri, which provides free trees for public and not-for-profit spaces.
Close to home, think of Joplin, which lost an estimated 15,000 trees. Check with the Missouri Department of Conservation’s Ric Mayer for how you can help.

It’s easy in the Ozarks to take trees for granted because we are blessed with such an abundance. But worldwide, I’ve learned we’re losing millions of acres of trees every year. The most serious logging and clearance for mining and ranching is not the Amazon but the boreal forests of Canada and Russia.
Trees shelter us, feed us, shade us, soothe us. Perhaps they also may keep this Earth livable: Trees are one of the Earth’s natural carbon sinks for absorbing the excess carbon dioxide that is turning this planet into the toasty oven we’ve suffered through this summer.  A single acre of trees absorbs enough CO2 over a year to equal the amount produced by driving a car 26,000 miles! For a list of “tree benefits,” go to www.treesofstrength.com.

As a Missouri Master Naturalist in the Springfield Plateau chapter, I appreciate trees even more than I did as a kid on horseback. I’m proud to be a tree hugger and hope more of you will love your trees and plant others. Just don’t forget to water.

Jennifer Ailor, as President of the Springfield Chapter of Master Naturalist, volunteers to share programs and information about our natural world to area groups. Learn more at http://springfieldmasternaturalist.com/


t

Thursday, August 23, 2012

Black Widow Spider


There is more than one reason to have you wife do the weeding of the garden. In addition to being lazy, I am always looking for interesting creatures, and she has the knack of finding them. Just two days after finding the nursery web spider with its egg sack, she came upon a whole different type of arachnid mother.
Barb lifted a concrete block along the garden fence and found this black widow guarding its egg sac.  It became fairly agitated when I got within an inch or two with my camera for macro pictures, so I switched to video mode seen here.


There are 32 species of widow spiders  in the Latrodectus genus including the three "black widows" in the US, the northern, southern and western.  They are named for the habit of eating their mates, although other female spiders and some female insects have the same heartless habit.

The common black widow we think of is the southern black widow, Latrodectus mactans.  The females are jet black with  the famous bright red hourglass on the abdomen.  The males may brown bands on their legs and red and white body markings.

The female has a much more potent neurotoxic venom than the male, delivered by unusually large venom glands.  Their bite is usually painless with symptoms frequently developing later, a trait reflected in its name, Latrodectus, Greek translated as “biting in secret”.  Less that one percent of bitten humans die, a comforting thought until you read the symptoms.
"This spider's bite is much feared because its venom is reported to be 15 times stronger than a rattlesnake's. In humans, bites produce muscle aches, nausea, and a paralysis of the diaphragm that can make breathing difficult; however, contrary to popular belief, most people who are bitten suffer no serious damage—let alone death. But bites can be fatal—usually to small children, the elderly, or the infirm. Fortunately, fatalities are fairly rare; the spiders are nonaggressive and bite only in self-defense, such as when someone accidentally sits on them."  nationalgeographic.com
 Like other cobweb weaving spiders of the Theridiidae family, they have two rows with four eyes each.  Unlike others in that family, their lateral eyes are "completely separated".  Similar to the identifying scale pattern under the tail of our venomous snakes, this identifying feature is not of much value to amateur naturalists, because if you can seen their eyes, it is probably to late.

Black widows tend to hide during the day, coming out at night or when something vibrates their tangled, three dimensional web.  They frequently hang on to their web upside down as seen in our picture above.

An interesting cousin of the black widow is the brown widow, Latrodectus geometricus which was found in Africa and the US around the same time.  They are a lighter color and have an orange hourglass on their abdomen.  A unique identifying feature is the distinctive egg sac which is covered with little spiky points.


Brown widow egg sac- Wikimedia
There is considerable debate about the toxicity of L. geometricus  venom.  Apparently is tends to remain around the bite rather than spreading, and their venom doses are smaller.

A recent report quoted in Sciencedaily suggest that the brown recluse is outcompeting its black cousin in Southern California.  The first US documentation was in Florida in 1935, and they weren't found in California until 2003.  Now they are much more common, found in areas previously harboring black widows.  This is good news only if you are fated to be bitten by one of the widows.

Addendum- June 29, 2013
The latest black widow we found was carrying an egg sac.  This gave me the opportunity to dissect the sac to see the eggs.  I was surprised to see the eggs roll out freely like a bag of marbles onto the table.  Unfortunately it was the kitchen table.  Note to self: open egg sacs outside.
Black widow egg sac
Eggs in case


David Quammen's essay The Face of a Spider has interesting thoughts on the relative value of a venomous species.  

Tuesday, August 21, 2012

Osage Orange

The drought has choked the wildflowers and muted the usual summer colors, leaving lots of gray and straw colored grass as well as yellowing of leaves.  The only color to be seen across the south field are the yellow-green balls hanging on a few distant trees.  You may have seen one close up on Saturday's blog quiz.*  These are the infamous hedge apples.

Osage orange Maclura pomifera, is a shrub or small tree, a member of the mulberry family.  Squint at the softball sized fruit and you can begin to see the resemblance to a mulberry.  This plant has an interesting history as well as a reproductive strategy which seems outdated for our modern world.

Like all other living organisms, procreation is "job one" for plants.  Seeds may be dispersed by wind or animals which eat them and pass them on.  The massive fruit of the Osage orange isn't regularly eaten by any native species aside from squirrels, although cattle and horses which arrived on this continent around 500 years ago will occasionally nibble them some. 

Osage orange native range- Wikimedia
The most interesting theory is that they were commonly eaten by the megafauna such as giant ground sloths, mammoths and mastodons prior to their extinction coincident with the arrival of humans 12,000 to 15,000 years ago.  They would have been capable of spreading their seeds in the temperate areas as the glaciers were retreating.  Like the honey locust with its large seed pods, the Osage orange comes complete with thorns capable of discouraging the browsing mouths of herbivores.**

Their home range in recent times was in Texas and a bit of Oklahoma.  Lewis and Clark sent cuttings acquired from Pierre Chouteau, a founding father of St. Louis, to President Thomas Jefferson but they failed to grow.  Osage orange had already achieved fame among many native American tribes as the best wood for making bows.  This is cited as one possible source of its early French name, bois d'arc, or "bow wood."

Osage orange is now naturalized throughout the United States.  It received its boost during the dust bowl days when 220 million trees were planted in shelter belts to reduce wind erosion.  Their spreading branches with short thorns made natural fences before barbed wire, then provided decay and termite resistant fence posts for the wire.

Dispersal by megafauna over thousands of years failed to accomplish what an invasive species of bipeds did in a hundred years.  There is a message here for future generations.
 
* I received a correct answer within the first hour.  Sarah Zahn recognized the closeup of a hedge apple, the fruit of the Osage orange.
** Discussed further in a previous blog.






Sunday, August 19, 2012

Spider Nursery


Side view of egg case- Click to enlarge
"I get by with a little help from my friends" *
                  -   Lennon / McCartney

Barb found this spider trapped in a waste basket in our well house.  The timing was perfect as we took the arachnid to Insectorama that night and before returning it to our well house maternity ward.  I, like everyone else, identified it as a "wolf spider."  Wrong!

By looking carefully you can see the egg case that she is carrying.  A wolf spider spins a silken pad to deliver the eggs onto, then wraps them up in several layers of silk and attaches them to her spinnerets.  She will haul the case around with her until the young emerge.  This is a unique characteristic of female wolf spiders. 

Dr. Chris Barnhart pointed out my error, a role usually assumed by Barb.  He noted that she is carrying the egg case in her jaws and pedipalps, not her spinnerets.  On looking at the picture above, you can see that her spinnerets at the tip of her abdomen do not contact the egg case.  This is an identifying characteristic of a nursery web spider.

Egg case is off the floor
Her dedication to her young is incredible.  First, holding the egg sac with her jaws precludes eating.  Her only defense against predators is escape or dropping the egg case.  In moving her about and recapturing her during one escape attempt, she held tenaciously to her maternal burden.

Second, carrying the egg sac below is an awkward arrangement at best.  She essentially walks on tiptoes (if a spider can be said to have toes) as she lifts the sac higher so the egg case doesn't drag.   This must be even worse than shopping in Walmart the week of your due date.

Nursery web - Wikimedia
Another key difference in the species is the nursery phase.  A wolf spider's young crawl out of the egg sac and up on to her back where they ride around for a while as she hunts.  They depart at their own pace, apparently ignored by the mother.

Nursery web spiders get their name from the next phase of motherhood.  She weaves a rather haphazard web and attaches the egg sac to it.  The spiderlings emerge and stay within the confines of the web while the mother guards the web.  After their second molt, the young disperse.**

Don't mess with Mama- Note the eyes
While I was photographing her at close range she charged the camera lens several times, trying to get out the little aquarium door.  This gave me a chance for a good closeup picture.  Wolf spiders have four small eyes in a row on the bottom, two large secondary eyes in the middle and two smaller ones on top.  This picture shows two rows, each with four equal sized eyes.  If I had seen her hostile stare I probably would have dropped the camera and stepped back.

Male nursery web spiders take a risk when approaching with mating in mind, as the larger female will frequently look at him as the main course.  To counter this, the males frequently approach cautiously with a "gift" such as a dead fly or some other food offering.  They are even known to bring an insect leg or some other inedible fragment to keep her busy.  That seems like the equivalent of coming in late and bringing your a bouquet of dandelions, but apparently it works some times.

Looking for nighttime entertainment with a real reality show?  Try finding spiders including wolf and nursery web varieties in the dark by their eyeshine, a tiny bright silver spot in the beam of a flashlight.  This is light reflecting off their tapetum, the reflective surface at the back of their eyes.  This same structure is what gives the eyeshine you see from deer and raccoons along the highway at night.

As you can see in this short clip from the clip from Youtube below, the spider doesn't have to be facing you.  The eyeshine is more obvious in real life than in the video.  It is important to hold the flashlight close to your face so the light reflects straight back to your eyes.  An LED headlamp is a good tool for this.

video

Our spider will soon be back patrolling the well house where there is a ready supply of baby food as well as lots of house crickets to entertain her kids with.

 We discussed other wolf spider habits in the past on this blog.
* That would be Chris Barnhart
** abugblog.blogspot.com

Saturday, August 18, 2012

What is It?

This is coming soon to the blog.  The first master naturalist or local blog follower to email me the identification wins a free mobile (not a phone) of their choice.*   One entry per reader.

* Shipping not included.

Wednesday, August 15, 2012

Jonah and the Hognose Snake

This story was just sent by Master Naturalist Caryn Fox.  The story in italics is in her own words and the pictures are from her Iphone.

Caryn:  "I'm involved with several rescue organizations for abandoned and stray pets.  Yesterday I had a rescue of a different sort to share on our blog. This time, I was hiking my trail with my trusty dogs when I came across a very small hognose snake in the middle of the path."

The Eastern hognosed snake is a beauty, and is harmless to larger mammals such as dogs and their bipedal masters.  They defend themselves by hissing loudly and spreading their necks out like a cobra.  They will strike, usually without biting, essentially head-butting the source of danger.  This cobra imitation is useful to fool those of us who have seen Indiana Jones or read Jungle Book, but presumably also has some survival benefit when faced by a curious dog or hungry fox.

Caryn: "My dogs, being very stealthy and all, were about to step on the poor snake, so I moved it out of the path. What happened next wouldn't be believable, except I saw it with my OWN eyes! The little snake flipped over to play dead, and promptly regurgitated its recent meal, a little frog."  

Up comes a frog
Now playing dead is nothing new for an Eastern hognosed snake- in fact they are rather famous for this trait.  Flipping on their backs they let loose a foul odor from their cloacas (a single opening for the urinary, genital and intestinal tract) and may let their tongues hang out of their mouths.

Amphibians make up a major part of the hognosed snake's diet.  They are immune to the toxins that toads produce.  They also have enlarged teeth in the rear of their mouths which will deflate a puffed up toad.  They actually will develop liver problems if they are fed only rodents.


Now here is where it gets a little weird.  The frog- let's just call him Jonah... well here is the rest of her story.
Frog on left- first breaths?

Caryn: "Upon closer inspection I noticed the frog was still breathing.  While the snake was still on its back the little frog revived and started to move."

A frog can stay under water for some time without suffocating.  As long as its skin remains moist it can extract oxygen from the water.  Presumably this frog hadn't been inside very long.  I put this question to Dr. Stan Trauth* who responded:
"The snake's stomach acids combined with the lack of oxygen would have killed the toad (or frog) rather quickly.  What she witnessed was pretty typical behavior for a hognose snake after it has been disturbed following a recent meal."
Amphibian- 1   Reptile- 0
Caryn:  "As the snake righted itself, the little frog hopped away (I helped it orient toward the woods so it wouldn't also get stepped on). Imagine the snake's surprise when it realized its meal was gone! Now that's a rescue of a different sort!" 

Actually I believe that should count as two rescues and one resuscitation. And the moral of the story for the frog?  Be careful where you hop or you may jump to your own conclusion.

Not a Hognose
Hognose- virginia.gov
 *  Dr. Stanley Trauth, Arkansas State University.  There are good pictures of the "cobra posture" at Herps of Arkansas.

Monday, August 13, 2012

Winners and Losers

How hot was it?  A fried squirrel.
I knew it had been hot when this squirrel sprawled out on the deck to cool off.  After another 100 degree day, it had dropped to 62 degrees deep in the valley.  This squirrel found the residual cool of the deck as the day warmed up and threw caution to the winds just three feet from where I sat.

Every change in nature creates winners and losers.  The drought and scorching temperatures this month creates lots of losers.  The winners are hard to find but they are there, those species that like it hot and dry.

Click to enlarge
Our local drought on Bull Creek has been even more severe than the surrounding area, getting no rain from the last three fronts passing through in June and July.  The creek bed is mostly dry gravel, a good 90% becoming a losing stream.

We had an unusual number of fawn sightings in early June with at least 4 separate does with 2 and one with 3 fawns.  We would see them every time we were out on the property.

Doe and fawn- Click to enla
The last two weeks we have found 3 dead spotted fawn and one doe at scattered locations without signs of predation.   In fifteen years prior we have only found 2 dead fawns.

This picture was taken along Red Bridge Road.  The doe was 15 feet away and made no move to run or even walk away.  You can appreciate her emaciation - note her flank in the picture below.  The fawn was also scrawny and moved very slowly, even though it appears to be several months old.

Note ribs and sunken flank
Aside from the tree and shrub leaves which are all drooping and dry, there are few weeds to browse and the fields are crisp with an inch of brown stubble.  I suspect that this is all the impact of drought and starvation, making them more susceptable to disease as well.  Deer that are sick frequently head to water, which is where we have found some of our dead deer.    

And what are the winners when it comes to drought?  One would be Horse Nettle, Solanum carolinense, virtually the only green plant in the garden area that we don't water.  It is growing all alone on stretches we sprayed two months ago in preparation for the fall garlic planting.

Not a true nettle, it is a member of the Solanaceae, or nightshade family. It is a perennial native of the southern United States and apparently loves the hot and dry climate.

Its fruit has been called the "devil's tomatoes" as they, like the whole plant, contain solanine, a toxic alkaloid.  Between toxicity and the tiny thorns, this means that the only green plant around can't be eaten by wildlife.

The drought has hit Kansas hard.  An Ellsworth Independent Reporter story describes a city law banning all outdoor watering, including gardens.  Ironically that doesn't include the city owned golf course because of the cost of replacement turf.  "We can't afford to lose the greens," according to the city administrator.  Once again, winners and losers.

MDC has information on deer diseases such as hemorrhagic disease and blue tongue.

Saturday, August 11, 2012

Harvestman

Click to enlarge
I enjoy watching a Granddaddy Longlegs hanging on the outside walls of our creek house any time, day or night.  Usually there are more in the vicinity, moving cautiously along the wall, reaching out with their incredibly spindly legs to touch one another as if to say, "Is that you? This is me."

They are one of the first insect-like creatures I learned to name.  "Granddaddy Longlegs" are harvestmen, arachnids in the order Opiliones.  The eight-legged Arachnida class incudes spiders, ticks and scorpions.  Occasionally spiders with exceptionally long legs are called granddaddys as well.

The harvestman's most striking feature are those long legs.  If we had the same leg to body ratio, our legs would be over 40 feet long!  You can tell them from spiders by their bodies.  Harvestmen have their cephalothorax (head and chest) fused with their abdomens, creating a single oval body.  Spiders such as the one below right, have a separate cephalothorax (tan in this case) and abdomen (colorful part below.)
Spider- abdomen & cephalothorax separate

Harvestman- fused abdomen












They differ from spiders in other ways as well.  For one, unlike spiders, harvestmen have no venom or silk glands.  While spiders suck up their calories as liquid, harvestmen have mouth parts that allow them to take in chunks of solid food.  This allows them an omnivorous diet, eating small insects, plant material and fungus, and in some species even dead organisms and bird dung.  They hunt prey primarily by ambush but some species stalk as well.

They can be seen, standing on six legs, swinging around their longer second pair of legs in the air.  These serve the function of antennae, sensing their surroundings.  Their front legs have three sections, ending in pincers used to groom, fight rivals and tear up food to deliver into their mouths.

Note red spots on leg
Frequently you will see harvestmen with 5-7 legs.  As a survival strategy, their legs can easily be detached by a predator.  (Notice the missing leg in the closeup picture above.)   Once detached, it continues to twitch for up to an hour, entertaining the predator while the harvestman moves on.  This occurs because of a clever pacemaker located in the femur (the segment nearest the body) which continues to send contraction signals intermittently down the leg.

They also have stink glands under the first pair of legs.  They signal that "You don't want to eat me- I taste terrible."  Another set of glands can lay a secretion for their colleagues to follow.

A female harvestman (how is that for an oxymoron?) has eggs fertilized by copulation via the male's penis.  She may deposit the eggs soon after or carry them for months.  The eggs then hatch anywhere from 20 to 180 days later!  The young go through 4-8 molts before reaching maturity.

Erythraeidae mites- Click to enlarge
One of my two specimens of Leiobunum vittatum  pictured also has another feature- mites!  It turns out that there are specific species of Erythraeidae mites whose larvae parasitize harvestmen.  The larvae bite a hole in the tough outer layer and insert a tubular stylostome through which they suck out body fluids.  You can see them dangling from the legs by their stylostome.  And I thought chiggers were bad!



MoBugs.com has a more comprehensive 2013 blog.
More information is at this texas site.











Thursday, August 9, 2012

Crayfish High and Dry

Fishing Hole?- Click to enlarge
The drought and scorching temperatures takes a toll on aquatic critters as shrinking water supplies constrict their living space.  With much of the middle section of Bull Creek dry, what little water moves is through losing streams under dry stretches of gravel hundreds of yards long.  Needless to say there isn't much oxygenation in what water remains.

There are lots of stories on the impact of the drought on fish and aquatic creatures.  To my surprise we can still find hog nosed suckers and few smallmouth bass in even the small areas of water upstream from the swimming hole.  That raised the question- just what do they do in a drought?

I got some information from our former fisheries biologist, Mary Culler:
"I trust that many of the critters in the stream were able to swim downstream to deeper waters near the lake, but I am sure there have been some that have been trapped in pools. When I was with MDC we worked on a study on Rock Creek near Roaring River and documented that several crayfish species burrow beneath the gravel towards the water table when the intermittent stream went dry.
It was a very interesting study, we would begin digging in the stream in an area that was completely dry, and within a foot deep there were several crayfish living beneath the stream bottom where they had enough moisture to survive. Also, at one site, we hit the water table and discovered a madtom catfish living about 6 inches below the dry stream bed."  The study from 2009 is published here.
Prairie Crayfish- MDC
This should not have surprised me as crayfish can live in environments seemingly devoid of water.  The colorful prairie crayfish lives its life on- what else? - prairies.  To quote from this article from MDC:
"The prairie crayfish occurs widely in grasslands and prairies of northern and western Missouri. It is sometimes called the grassland crayfish. It lives in burrows that are often a long distance from any surface water. These may be six feet of more in depth. Most public prairies in Missouri support large populations, but this crayfish is seldom seen by visitors because of its secretive habits."
The prairie crayfish is a valuable member of the prairie community.  The crawfish frog (Lithobates areolatus depends on the crayfish for its year round home.  Other species also use these tunnels including snakes, lizards, frogs, and other amphibians.  Gratitude being in short supply in nature, some of these same creatures will dine of the crayfish as well.

Although the aquatic populations of Bull Creek are undoubtedly set back a few years, they will return to previous levels in a few years.  They just have to "dig in" for a while.


Tuesday, August 7, 2012

Hummingbird Breeze

Even with the hundred degree days, Bull Creek valley frequently reaches the low to mid sixties around 6:00 AM, sheltered as it is from the early morning and late evening sun.  Sitting in the porch swing reading the other morning, my legs were actually a little chilly.  Then I realized that the breeze seemed to be hitting all sides of my bare legs.

No wind was stirring the dangling shriveled leaves which were falling straight down when their petioles gave up their dry, tenuous grasp on their twigs.  There were hummingbirds swarming the feeders just three feet above my head, more than twenty were fighting for one of the spigots, only to be driven away by several rivals.  Suddenly it hit me that I was feeling the wind from their collective wings, and unnatural, or rather nature-al breeze.  

video

Without moving, I got out my pocket camera, grateful again for technology that allows recording much of what we see in nature, including videos.  After several minutes of filming, I returned to reading in the air-conditioned comfort of a porch swing, enjoying the busy humming of battling birds.

We are seeing hummers all day long now, going through two quarts of sugar water a day.  This is a record for us and probably relates to the nearly complete lack of nectar resources in the valley.  Trumpet vine is now blooming, one of their only alternatives.  Maybe on the other hand they like the chance to compete with their friends in an aerial game.  Remember, they have no internet connection and their tiny little cell phones don't get reception in the valley.

Either way I am happy for their company, and for the hummingbird breeze.

Sunday, August 5, 2012

Ivory-marked Borer

Ivory-marked Borer- Eburia quadrigeminata
This beautiful beetle was easy to identify as a long-horn beetle.  The key characteristic of that family is antennae which are far longer that their body.  After searching through the long-horn beetles in all my insect guides I finally found this 1/2" long beetle in the Cerambycidae family of long-horn beetles.

In addition to its extremely long antennae, its beautiful ivory spots are raised like ivory inlays on an old fashioned piece of furniture.  This is appropriate as described in its story below.

The Ivory-marked Borer/Beetle Eburia quadrigeminata eats leaves and twigs.   Their eggs are laid in the cracks of dead trees.  Their larvae bore into the solid heartwood which isn't as nutritious as live trees.  They may stay when the wood after harvest, becoming a part of a wall or furniture.

This beetle is not just another pretty insect but has a great story to tell. It has one of the longest life cycles documented. It usually goes from egg to adult over 2 years, but has emerged from flooring, beams and furniture 10 to 15 years after the materials were manufactured. To quote the University of Florida Book of Insect Records:
"The wood boring beetle, Eburia quadrigeminata (Cerambycidae), when feeding in dry wood, may have its development so greatly retarded that adults emerge from furniture and flooring many years after manufacture or installation. Delayed emergence of E. quadrigeminata in 1915 was discovered from a birch bookcase 40 years old."
One woman called a pest control company after hearing a gnawing in her house. They found this borer in a five year old chair! In another case, E. Quadrigeminata crawled out into a Cairo Egypt home out of an imported French cabinet, the first known finding in Africa. Talk about an invasive species!


Friday, August 3, 2012

Road Killers

One test of human nature is whether a driver tries to avoid hitting a turtle when it is safe to do so.  A more interesting test is what kind of driver would go out of the way to hit one.  An interesting "scientific study" has provided the answer.

An investigator put either a rubber snake, a rubber turtle or a rubber tarantula on the shoulder of a highway and recorded who swerved to hit them.  He used a rubber leaf as a control although that might have been harder to see from a car.  The results from 1000 vehicles studied were very interesting.
  • Four percent of drivers stopped to move the "animal" to safety. (Never the tarantula)
  • Six percent swerved onto the shoulder to hit it
  • The frequency of attempted animal murder?  Turtle- 1%  Snake-  1.8%  Tarantula- 3.2%
  • The "killer vehicles"?  Trucks and SUVs- 89%  Cars- 11%
For the "gory" examples and a little naturalist fun, watch this Youtube video.

Wednesday, August 1, 2012

Pine Ridge Church Snakes

Pine Ridge church
The last blog on Bull Creek neighbors' reports of clusters of copperheads gathering around their houses reminded me of a past news story.  In 1965 through 1967 there were several newspaper stories about venomous snakes congregating around Pine Ridge Church during gospel services with music.  The church is only five miles from our Bull Mills place.

In Tales of Bull Creek, the late John Mitchell describes visiting relatives on Highway H around July 20th, 1965.  He encountered a man carrying a large box. When asked the man what was in it, he replied, "Copperheads.  We are having a revival at the Pine Ridge Church and when the hymn singing starts the snakes come from everywhere.  We've killed over a hundred so far."  Curious about this, he went over to the church where he describes the scene:
"There an amazing sight awaited us.  While part of the congregation were singing to the accompaniment of guitars in the church house, others, men and boys, were outside with flashlights and rifles shooting snakes.  The church yard and surrounding brush land were alive with crawling copperheads." *
John went to the Springfield News-Leader the next morning and told Frank Farmer the story.  They went back to the church the next evening and when the music started, the snakes returned and the shooting started anew.  Frank Farmer's Pine Ridge story** in the News-Leader was picked up by national newspapers, the 60's version of "going viral" before Youtube.

This event led to the Pine Ridge Snake Hunt which was held annually for  about 10 years, benefiting charity in Chadwick, Missouri which was called the Copperhead Capitol.  There were prizes for the most snakes killed and the largest and second largest venomous snake.  It ended in cooperation with the Missouri Department of Conservation.

Pine Ridge Church still is going strong and this picture of a later "snake hunt" is off their blog.  The handwritten caption says "the start of the Pine Ridge copperhead snake hunt."  As a sign of the times, Pine Ridge Church is currently preparing to replace the outhouses with indoor toilets.  Copperheads didn't stop the trips to "the necessary" but increased bear sightings have.

Based on the Pine Ridge Church story I was going to stop singing and playing the guitar on our deck on Bull Creek, but Barb feels that my singing will actually repel snakes.

*    Chapter from Tales of Bull Creek
**  Newspaper Stories of the time.
Editor's note:  Pine Ridge Church is just down the road from our "Pine Ridge Dan" Crane's cabin.
addendum August 2017.  More history at Ozarks Alive.