Sunday, November 28, 2010

Ant Farmers Use Pesticide

Leaf-cutter ants- Wikipedia
Ants beat us to the discovery of pesticide use by millions of years.  A report in Livescience.com describes the association of leaf-cutter ants and the fungus crop they raise with the help of bacteria.
 
There are at least 230 species which farm fungus on leaves to eat as a primary food source.  Another fungus, called Escovopsis attacks and parasitizes the ant's fungal crop.  The ants have learned to "weed" the leaves by lapping up the spores of the invaders.

Previous studies have shown that the ants carry bacteria on their bodies.  These have been identified as Pseudonocardia, related to bacteria that have led to the discovery of antibiotic agents in the past.  What is new is a report in the Proceedings of the Royal Society which has shown that leaf cutter ants carried predominately two specific strains.
"The researchers also tested how effective different Pseudonocardia strains were in suppressing fungal growth, particularly that of the ants' nemesis Escovopsis. Here, they found that the parasite was more susceptible to the antibiotics produced by Pseudonocardia than were other fungi. They also noticed that strains of Pseudonocardia found dwelling on ants were more effective against the parasite than free-living strains." 
When ant queens take flight to set up a new colony, they carry the fungus with them, ready to start a new farming operation like we carry seeds of familiar crops.  Also like us, they may carry the parasitic fungus, an early form of an "invasive species".  

An instructive video from Science Nation demonstrates the ants at work.  Research may even lead to the discovery of new antibiotics or how leaves might be converted to biofuel.

Friday, November 26, 2010

Bobcat Melodies

Do you ever hear night time animal cries and wonder what made them?   Birds and mammals can make some scary sounds which are difficult to identify.
We were discussing sightings of bobcats while sitting around a fire at the Missouri Native Plant Society meeting last week.  Suddenly we heard distant haunting night sounds, a cross between a baby's cry and a screech owl.  Most of us guessed it was a bobcat cry.

According to Wikipedia, bobcats (Lynx rufus) are crepuscular, that is they are active in the hours around dawn and dusk.  This is a time that brings out certain species such as deer, rabbits, rodents, skunks, as well as many insects.
"The bobcat is crepuscular. It keeps on the move from three hours before sunset until about midnight, and then again from before dawn until three hours after sunrise. Each night it will move from 2 to 7 miles (3.2 to 11 km) along its habitual route.[13] This behavior may vary seasonally, as bobcats become more diurnal (active during the day) during fall and winter. This is a response to the activity of their prey, which are more active during the day in colder months.[12]
Was it a bobcat?  Who knows?  Cats have a wide variety of vocalizations (think Tabby's meow, hissing at the dog, and mating cats under your window at night.)  It turns out that bobcats are also versatile vocalizers.
There is some help on animal sounds available on the Web.  Many sites like junglewalk.com and thryomanes are geared to exotic animals from around the world.  An extensive library of audio and video can be found at macaulaylibrary.org.  I was not successful in finding a single source for North American mammal sounds.  Let me know if you can find a good source. I did find a variety of bobcat vocalizations at http://www.soundboard.com/category/Science-Nature.aspx.  From now on, I will probably think every nocturnal muffled scream is a bobcat until proven otherwise.

You can read this Missouri Conservationist  article on bobcats from the May issue.

Tuesday, November 23, 2010

Complex Mayflies

Mayfly- Click to enlarge
I have been under the impression that the presence of mayfly larvae in a stream is an indicator of high quality water with good oxygenation.  In some cases that is true, but the whole story is more complex.

There are 15 families of Mayflies found in Missouri,  all lumped in the order Ephemeroptera.  The name reflects their ephemeral existence because of the mouthless adults life span of a few hours to two days.
We tend to think of their presence in streams as an indicator of good oxygenation because some species with fixed gills require flowing water with adequate oxygen content.  It turns out that some other species have developed motile gills to tolerate lentic* (still) water in ponds and lakes as well as low oxygen conditions.

The larvae that we look for in macroinvertebrate sampling will molt from 12 to 45 times over two weeks to two years before reaching adulthood.  Even then they are not done, as the last molt before adulthood is quite different from a human teenager.  It comes out as a "dun", a dull colored, sexually immature winged creature which then molts into the adult capable of mating.  No other insect has this intermediate form.

Swarm hatch on truck
Although many mayflies deposit their eggs in masses by dipping their ovipositor in the water as they fly, others drop them singly or from the air over water.  When the eggs hit the water they begin to develop immediately.  A female may drop as many at 500-3000 or more.  If they drop them all at one time, there may be a swarm hatch all at once, sometimes dramatic in number.

Mayfly nymphs usually live on detritus or algae which they scrape off the stream bottom.  For this reason, well oxygenated streams with clean silt free bottoms are especially important as the nymphs fulfill a reluctant role near the bottom of the food chain. While some have evolved to withstand low oxygen and stagnant waters, the presence of lots of nymphs in lotic* (moving) water is usually an indicator of good quality water.  Trout fishermen (the top of the food chain?) also use Mayflies' presence to help them choose which fly to tie on.  You gotta love them.


The Missouri Stream Team newsletter has all this information and a lot more.  Just go to their
facts site  and download #14.

*Words for the day:
Lentic ecosystems are still waters such as marshes, ponds, and lakes. 
Lotic ecosystems have flowing water such as springs, creeks and rivers.
Now don't you feel better?

Sunday, November 21, 2010

Ain't Nothing Shaking

National Institute of Biology, Slovenia
We think of insects communicating with clicks and chirps, but shaking?  A story in livescience.com* explains the mechanics of stinkbug communication, and it ain't stink.  It turns out that stinkbugs and burrower bug's leafy habitat isn't just for eating and shelter.

Researchers used lasers to detect the vibrations on leaves created by 21 different species of bugs they studied.  The vibrations are very low frequency but would be audible to us if they were louder.  The principal is similar to a tin can telephone, very rudimentary, but pretty sophisticated for a bug only one-half inch long.
"The insects displayed a wide array of vibration-producing methods, from fluttering their abdomens to shaking their entire bodies to tapping their front legs on the plant surface. Different species had different vibration patterns, limiting cross talk. Male and females of the same species also had distinct calls. For example, the researchers reported, female southern green stinkbugs call out with relatively long vibrations spaced far apart, while males call out with short bursts of vibration spaced closer together."
Different species produced a variety of frequencies, patterns and durations of calls.  Some shook their whole bodies, other just tapped their front legs on the leaf.  However they did it, it turned on another bug.  Just think, the old rock song "Ain't Nothing Shaking but the Leaves in the Trees," might have been a love song among stink bugs.

* Reported November 18, 2010 in Cancun, Mexico, at the second Pan-American/Iberian Meeting on Acoustics by researchers from the National Institute of Biology in Slovenia.

Thursday, November 18, 2010

This from Bob Ranney
 On January 22, the MO League of Conservation Voters will hold an open conference on conservation related legislative issues to be faced in Missouri over the next year.  The meeting will be on the MU campus in Columbia.  Participants will have access to a wide range of presentations, but also must select a breakout session they want to attend.  The subjects include:
    • Citizen Advocacy
    • Climate Change
    • Energy and Green Building
    • The Green Economy/Jobs
    • Public Land Use
    • Solid Waste Reduction
    • Sustainable Agriculture
    • Transportation and Land Use
    • Water/Floodplain development
This should be a very informative conference that will bring us up to date on issues of concern to all conservation oriented Missourians.  Because the emphasis here is on legislative action, we can’t go as representatives of our chapter, but it would be great if a group of us could go together.
For more information go to this web site.


To sign up for carpool, call Bob Ranney at 417-379-1757 or email rjranney@sbcglobal.net

American Burying Beetle

from Wikimedia
I just finished reading an article* by the Director of the Center for American Burying Beetle Conservation (CABBC).  In the words of Dave Barry, "I am not making this up."  Behind this long name lies a interesting story.

The American Burying Beetle (Nicophorus americanus) is an endangered species initially found in 35 states but now only occasionally is found in seven.  In addition to its colorful body, its colorful habits are worth exploring.

The beetles are drawn to the smell of decomposing flesh from as far away as two miles!  Once there, they mate (gets a little strange, doesn't it?) and then go about burying the carcass.  The may lay on their back together and use their 12 little legs to move the body to the right spot.  Once there, they strip off any fur and feathers, converting it into a little meatball which they cover with antibacterial secretions.

They live underground most of the time as their kids are growing up.  They can call their cute little white larva to supper with squeaking sounds they make with their wings.  They actually feed the little ones when they are young by regurgitating partially eaten rotten meat into their mouths.  Apparently their young don't like brocolli either.

Like other burying beetles, americanus carries mites on its body.  Somewhat disgusting to look at under magnification, they serve a purpose.  The mites eat fly maggots that are voracious competition for the dead meat so they are apparently welcomed passengers.  As my mother would say, "Each to his own taste said the woman as she kissed her cow."

The CABBC is located at the St. Louis Zoo.  There they raise the beetles in captivity and are considering reintroducing the beetle into the wild.  As you can see from the map, we are close to the known range for the americanus which is still found in Arkansas and Oklahoma.  Keep your eyes open and maybe you can put Missouri on the map.


* From Missouri Update, a publication of the Nature Conservancy.  To read the story, Go to http://www.nature.org/wherewework/northamerica/states/missouri/, then click on the bison photo that’s labeled "Read the 2010 Missouri Update" to download the pdf file.  The Nature's Undertaker article is on Page 14.  While you are at it, Page 1-5 has a good story on Bison.

Sunday, November 14, 2010

Stream Nutrients

Determining the health of a stream is complex, especially when you factor in the factors of location, soil, and especially the impact of human activity on the watershed.  Any attempt to develop a standard scale is all the more difficult.
Take for example the nutrient levels of  total nitrogen (TN) and total phosphorus (TP).  In the words of the Missouri Department of Natural Resources on the DNR Website:
"Too much nutrient loading to a water body can cause rapid growth of algal blooms, organic enrichment and depletion of dissolved oxygen. Too little may result in insufficient enrichment of the aquatic food chain, which would be detrimental to a healthy aquatic biological community."
It is complicated further by the varying geology and human density around the state, making it difficult to set a standard for the state.  A heavily karst region like the Ozarks will have smaller nutrient levels that a muddy Northern Missouri stream.  The answer to which is better?  "It depends."
One thing we know is that our Stream Team monitoring is an important tool in the assessment of the stream health.
"An assessment of algal, macroinvertebrate, and fish communities in streams with low-level nutrients found that algal communities correlated well with increasing nutrient levels. Using algal community data to investigate nutrient conditions have been shown to be a successful method in many water-quality monitoring programs."

Unfortunately, there are tremendous scientific and political opinions on what Numeric Nutrient criteria should be.  I suspect that any criteria put out, like many other solid numeric criteria such as the econimic numbers we read daily, will be the "best guess" available at the time, interpreted by the organization with the "Final Word.'
This isn't meant as criticism, just an observation that with complex data, sometimes you just have to take a position to believe in and adjust it later.  In the words of a famous philosopher:

"Everybody should believe in something. I believe I'll have another drink."
                              — W.C. Fields
David Casaletto* wrote the story in the Ozarks Water Watch newsletter quoted above that has a lot of good information on the subject.  This is a great resource for other local water issues and is available by email simply by signing up at http://www.uwrb.org/

* David Casaletto is the President and executive director of Ozarks water Watch and Acting executive director of Table Rock Lake Water Quality.

Friday, November 12, 2010

Gnarley Beaks

Chickadee- USGS Photo
Avian Keratin Disorder

Mysterious new disorders in wildlife are always worrisome signs of possible pollution or other human impacts on wildlife.  Some like white nose syndrome signal a new infectious disease.  Others like the thinning of egg shells in birds of prey and waterfowl have led to the banning of DDT, an action which may have contributed to the comeback of the bald eagle.

A new troubling finding called Avian Keratin Disorder is cropping up in the Arctic.  There is a rising incidence of beak disorders in Alaska and the Pacific northwest.  Initially noted in a few crows, it is now estimated to occur in 17% of the coastal Alaska crow population.  Now it is found in 6.5 percent of adult black-capped chickadees in Alaska.
"The keratin layer of the beak becomes overgrown, resulting in elongated and often crossed beaks. The deformity showed up in adults birds, most often in the upper beak but sometimes in the lower beak or both.  The abnormality sometimes is accompanied by elongated claws, abnormal skin or variations in feather color." *
Nuthatches and woodpeckers have lately been seen with beak distortions as well.  They all have in common the tendency to live year round in the area, but they have totally different food sources and habitats.  These factors suggest that the disorder is spreading.

The cause is unknown with theories including infection, nutritional deficiencies and pollution as factors.  Similar problems have been associated with environmental pollutants such as organochlorines in the Great Lakes region and selenium from agricultural runoff in California.  There should be more information as awareness of the condition increases.

*This story as reported in the Los Angeles Times.    The study is available in abstract in Auk, a Quarterly Journal of Ornithology.
Lisa Berger provided a 2007 resource that has a much deeper look at the disorder.  Download this pdf   

Thursday, November 11, 2010

Unlikely Bedfellows

"Politics makes strange bedfellows"
   -Charles Dudley Warner (1850)

What brings together a brothel, a staunch opponent of the Endangered Species Act, and the Nevada Department of Wildlife?  You guessed it, a threatened Amargosa toad.  This inspiring story is reported on NPR.  In today's atmosphere of blame and angry voices, this is a model of the combined interests of groups with different agendas creating a common good.

First the toad, a desert species which survives along a small river and in warm springs of a xeric climate.  Ranching, mining and off-road racing in the Oasis Valley have been associated with declining numbers of the toad and calls to put it on the endangered species list.
Enter David Spicer, a rancher, himself feeling endangered by the potential threat to his way of life by the Endangered Species Act and his distrust of government intervention.   In stead of a militant attack on the forces of government, he creates habitat for the toad, increasing their numbers.  From the NPR story:
"What you're seeing tonight are the results of active land management, active habitat management," Spicer says.  He has run miles of underground pipe around his property to create breeding pools and wet habitat for the toads.  Spicer grew up with the toads and wants to preserve them, he says.
But here's the surprising thing: Another reason, and perhaps the major reason Spicer has gone to such lengths is because he really, really does not like the Endangered Species Act.
"Nobody trusts the government anymore," Spicer says. "Nobody wants to work with the government. The government always wants to take something from you."

There are still 24 species in the area that are endangered or threatened, so there is a lot of work to be done.  The hopeful lesson to draw from this is that we don't have to agree with each other's political philosophy if we can find common cause in an outcome.  For instance, protecting your land and way of life as well as a toad.

And the brothel?  Sorry, you have to read the story at NPR.

Wednesday, November 10, 2010

Rain Barrels in Winter

Rain barrel winterizing advice from Karl Haworth.

Well it's that time of year again and freezing temps are here. For those of you who put in rain barrels during the summer wasn't it wonderful to have rain water for your plants. I used one of my barrels to keep my fish pond filled as the evaporation during the hot spells dropped the water level.
Now is the time to put the barrels away to await a warm spring day. I have one still in operation but the temps in the low 20's can cause damage to the connections and extended cold can rupture the barrel. Last year I tried to leave the hose connections open at the bottom thinking that would work but  alas not so good.
This year I have taken the barrels out of operation and used 4 inch plastic drainage pipe to fit between the gutter drain pipe and the over flow which with my system goes under ground. Or you can just put a section on the down spout to carry the water away from the house. It is important to have tubing as large as the rain gutter pipe keeping water away from the foundation to prevent a cracked foundation.
Maybe in the future we can come up with a design that will work better with freezing weather but I still think it is a good idea to empty any debris in the bottom and turn the barrels bottom up till spring.

Plans to make a rain barrel are at this Springfield website.  Much more information, a video and a discount offer is at here.

Tuesday, November 9, 2010

Mite-y Beetle Families

Click to enlarge
I came across several of these beetles when a rotted piece of firewood broke apart.  Their distinctive appearance makes them easy to identify as a Horned Passalus (Odontotaenius disjunctus),  a.k.a. Bess Beetle or Patent Leather Beetle for its shiny body.  It is a member of the Passalidae family.  It is unique in the family in its ability to stand freezing temperatures.  Unlike many insects species which are hard to separate, the horned Passalus is the only species in the family which occurs in the US north of Texas and Florida.

The Horned Passalus is the "largest showy beetle in the US". *  "The prontium (back plate of the thorax) is square with a deep middle grove, separated from a deeply grooved  elytra by a deep waist".**   It has powerful mandibles capable of chewing through oak but do not bite and can be safely handled (if handling beetles is your thing).

These  beetles and their families live their entire life in well rotted wood.  I call them families because they are a rather tightly knitted group.  The white grub-like larva cannot eat by themselves and are fed with food which has been chewed by the adults.  Their nutrients must include microorganisms, as the larva won't develop in sterilized rotted wood.

Adults communicate by stridulation (squeaky sounds made by rubbing body segments together), creating at least fourteen different calls.   I can picture a patient graduate student with a tiny microphone hovering over a rotten log, wondering what they are saying to each other.  I suspect they are saying, "Doesn't this highly educated, advanced biped have something better to do?"  Update November 2015-  Check out their stridulation at this link.  Recorded by Will, Kaiden and Hilton at the WOLF School. ****  

Mites under "chin"
Notice the mites on the underside of the beetle to the right.***  Many beetles carry mites as passengers.  This is particularly true of beetles that live underground or in dead vegetation. We discussed this in the blog about Sexton beetles.  You "mite" be even more interested in the beetle/mite association.  If so go to Macromites Blog.

Like a few other beetles, my friend has been on his back, unable to roll over without help.  I suspect that if you spent your entire life in rotted wood chambers with something to hang on to, you would consider learning to roll over a waste of time.  When I put him back in his log, I thought I heard him squeak out a "Thanks".

*      Beetles, Peterson Field Guides
**    National Audubon Field Guide to North American Insects and Spiders, p. 555.

***  "Passalids almost invariably have associated mites - several families of mites are found ONLY in association with passalids, and many genera and species are similarly restricted - suggesting a very long association between the two groups.   I know of no mites that are harmful to the passalids, although there may well be some (e.g. tracheal inhabitants)."  (Herper.com)
**** WOLF is a 5th grade school focusing on nature studies and conservation.

Sunday, November 7, 2010

Fruits of Fall- Part II

Buckbrush Symphoricarpos orbiculatus
 
Click to enlarge
Much as learning the Latin names can be a pain, I again learned their value.  After looking up buck brush and finding it didn’t fit my common plant, I discovered there is buck brush and buckbrush (without the space)!
Our common “buckbrush” produces dense clusters of small quarter inch coral red fruit, each with two pale smooth seeds.  It is browsed by white tail deer, but is eaten by birds and small mammals only when they are desperate.  Cattle avoid it so it is frequently found around the edges of fields which have been grazed in the past.

Multiflora Rose Rosa multiflora

Multiflora Rose
Love the fruit- hate the plant!  Originally introduced from Asia, it was thought to be of value as a natural hedge for cattle.  It was also valued as it (1) grows well without any care + (2) has no natural predators + (3) can grow anywhere = INVASIVE SPECIES.   It has vicious recurved thorns which grab and hold on to you.

It was planted by some transportation departments along roads as a crash barrier.  I don't know if it stops a crashing car or whether a careening car avoids it because of the thorns!  Another supposed virtue was its ability to attract wildlife.  The fruit (technically rose hips) are colorful and apparently tasty in the spring and attract wildlife, tricking them into spreading its seed everywhere a bird can poop. 
"Multiflora rose reproduces by seed and by forming new plants that root from the tips of arching canes that contact the ground. Fruits are readily sought after by birds which are the primary dispersers of its seed. It has been estimated that an average multiflora rose plant may produce a million seeds per year, which may remain viable in the soil for up to twenty years. Germination of multiflora rose seeds is enhanced by passing through the digestive tract of birds" DCNR
More information is at the Plant Conservation Alliance "Least Wanted" site.
Wikipedia

Friday, November 5, 2010

Asian Lady Beetles

Last week, shortly after the first freeze of the year, I was up at Three Trees, an open vista on a ridge with three large oaks in a cluster.  Each time I stopped there I noticed little bites on my exposed skin.  I was being swarmed with Asian Lady Bugs, Harmonia axyridis, which I hadn't encountered anywhere else.  Each afternoon this would occur only there.  Swiping them off my skin left their faint foul scent on my hands.

Why only here?  Tim Smith answered the question in the Missouri Conservationist Ask the Ombudsman column several days later.  To quote him:
"Each fall, during a warm-up following the first cold weather, the insects gather on the sunny sides of houses and other structures as they look for cracks and crevices where they can find shelter from the coming winter.  Many will survive the winter and appear again in the spring as temperatures warm and they try to exit the house."
Hackberry Bark
 Right beside the three shaded oaks stands a large hackberry tree, its bark exposed to the warm sun.  And there they were, crawling around its deep bark fissures, looking for a warm winter shelter.  At least these were out in nature rather than joining the hundreds that choose to live with us at our house.

Tim provided more information on the MDC Fresh Afield blog last year.  According to Wikipedia, they were brought to the United States in 1916 to control insect pests of plants, but were not successful.  In 1988 they were observed in numbers in New Orleans, and since then they have spread.  By 1995 they were occasionally found in the Midwest and became common in 2000.

Subsequently, they have also contributed to the decline in native ladybugs, presumably by out competing them.  They also have reached pest status to the higher biped mammals, both because of the swarming numbers, their little bites and unpleasant odors and the tendency to move into our buildings.  For information on these pests including control recommendations, check out http://ohioline.osu.edu/hse-fact/1030.html

Bearly Tracking in the Ozarks, Part 2

In one of last month's blogs I wrote about the Missouri Department of Conservation bear tracking project.  The goal was to trap 15 bears and attach GPS collars which will track their travel for a year before automatically coming off.  Our land on Bull Creek has attracted bears in the past and we set up a bait station to try and catch one.  Nearby sites had luck, in one case catching the same bear several times and recording its rapid weight gain.  GPS readings showed that it passed through our area but it never hit our food. 

The technique begins with attracting bears with desirable odors such as rotting shad and sardines, peanut butter and anise oil.  Bears have an acute (but apparently not sophisticated) sense of smell, seven times as sensitive as a bloodhounds.*   Once they arrive they would feast on out of date pastry which was replaced daily.  Jelly pastry is supposed to be especially savored, although its charm was lost on me after it sat in the barn for 1-2 weeks.

Click to enlarge
The pastry began disappearing daily and a game camera showed a raccoon who soon invited some of his friends for dinner.  Over two months we developed a supper club of six raccoons.  Several seemed to gain weight over the weeks and we had to start the two fattest ones on insulin.  Last week they built a small shrine and started worshiping me as the God of Food.  Incidentally, today's word from Mark Bower- a group of raccoons is called a "gaze".

Soon we had pictures of deer that came by to sniff but being strict vegans, they passed on the treats.  Then we had pictures of several visits from Wily Coyote and his friends, (a "band") apparently ignored the raccoons as their numbers never decreased.
The pastry was replaced every 1-2 days with the help of my neighbors, Larry, Doug and Willie.  I have several butt pictures of them at work.  Those will be the subject of a later blog if they don't pay up promptly.

After several months with no results we are winding down the effort.  We are close to the Cobb Ridge Campground where campers throw their food in the fire ring before they leave, so we had stiff competition.  And, I will be bring pastries to the next Master Naturalist meeting.

Americanbear.org

Thursday, November 4, 2010

Paulownia

My neighbor Larry Whiteley and his 10-year old granddaughter Anna Whiteley showed up after a youth season deer hunt with an unexpected trophy from our timber stand improvement.  It was time to "Stump the Master Naturalist", something that is not at all difficult to do.  The leaf measured 22" across and the stalk was moist and somewhat hollow in the center.  It looked exotic, more likely to live in a jungle.

An email to our favorite MDC forester brought an immediate response, (I think she was sitting there waiting for my next question). "Paulownia!"  Since it was on our land, we knew it had to be an invasive species.  Right again.

The Princess Tree, Paulownia tomentosa, was introduced as an ornamental and landscape tree around 1840.  The wood has commercial uses as quality furniture wood, veneer, carving wood and for musical instruments in addition to its pulp wood potential.
"Royal Paulownia is a native of China has a most dramatic, coarse-textured appearance, with its huge heart-shaped leaves and large clusters of lavender flowers in the spring. Paulownia flowers are borne before leaf emergence so they stand out nicely, especially against an evergreen background. With a rapid growth rate, Princess Tree can reach 50 feet in height with an equal spread in an open landscape."  About.com
So why are they invasive?  Part of the answer it found in NPS Least Wanted.
"Princess tree can reproduce from seed or from root sprouts; the latter can grow more than 15 feet in a single season.  The root branches are shallow and horizontal without a strong taproot.   Seed-forming pollen is fully developed before the onset of winter and the insect-pollinated flowers open in spring.  A single tree is capable of producing an estimated twenty million seeds that are easily transported long distances by wind and water and may germinate shortly after reaching suitable soil.  Seedlings grow quickly and flower in 8-10 years.  Mature trees are often structurally unsound and rarely live more than 70 years."

Click to enlarge
How did its winged seeds get up to a heavily wooded hillside miles from any garden?  Who knows?  How invasive it is only time will tell.  However, if this picture is any indication, they are here to stay in our urban environments.  Lets just hope that they can be converted to biofuel.

See an extensive collection of pictures at Invasive.org
Wikipedia on Paulownia

Wednesday, November 3, 2010

Sensitive Briar

Click to enlarge
I came across one of my favorite plants while hiking our glade.  The Sensitive Brier (a.k.a. Catclaw Brier) or Mimosa nuttallii is a delicate plant which is quite shy.  Its fame comes from its ability to fold up its leaflets temporarily when it is touched or sometimes when the sky turns overcast.

The pictures to the right are before and after a light touch.  The action takes place in less than a second.  Cleverly called "rapid plant movement", it is a property of several plants in the Mimosa family.  The Venus Flytrap's capture of insects is another example of rapid plant movement.  Also some plants are able to flip out pollen with their petals at half the speed of sound!
One second later
By clicking on the picture, you can appreciate the small recurved thorns on the stem.  When brushing the leaves to get them to perform, the thorns painfully remind me to go easy. In spite of these tiny thorns, cattle love to graze on the brier.
Beautiful delicate blossoms appear in early summer.  A more detailed description is at Wikipedia.  You can watch the leaves fold up in a short video of another Mimosa species.

Tuesday, November 2, 2010

Sadness of Frost Flowers


A Sadness of Frost Flowers
Click to enlarge
Looking out the window at Bull Creek after the first hard frost, I feel the excitement and sadness of seeing frost flowers.  White clumps around the base of dried stems. looking like windblown tissues along the road.  You have to bundle up and go outside to appreciate the delicate curls of ice, ribbons so thin that you can see your fingerprint through them.  They can vary in height and width, but never fail to create delicate curves.    
The immediate sadness comes when I realize that another year has passed.  It heralds the end of garden vegetables, the disappearance of many insects which have provoked wonder over the last year, the last of the native flowers and soon, the last of the colored leaves of fall.  But most of all, another year has passed, each one passing more swiftly.

Frost flowers are not commonly planted by by humans.*  Nature decides where and when they appear, the random acts of seed dispersal and neglect.  Frost weed (Verbisina virginica) and yellow ironweed (Verbisina alternafolia), their most common hosts, grow along the edges of our fields and roads, pretty enough when flowering but ignored when among much more dramatic and colorful competitors that most would call desirable.  They are the wardrobe assistants in nature's beauty pageant.  To my knowledge, few gardeners ever deliberately plant them.

Pealed stems- Click to enlarge
Once the "flowers" are gone, the dead plant base is left with its peeled epidermis.  Usually the next hard frost or two will create smaller flowers of narrow ice ribbons around the base as nature squeezes the last drop of liquid up from the roots.  Fear not, for Verbesina is one tough dude, it will be back in numbers next year.

Over time, people have invented collective nouns for groups of animals- a murder of crows, a gaze of raccoons.  There is a shorter list of collective nouns for plants- copse of trees, a rope of onions.
I would propose calling a cluster of these winter beauties a "sadness of frost flowers."

* Last months blog on Frost flowers mechanisms.

Monday, November 1, 2010

Sticks in Love

Click to enlarge
Stick insects seem to come out in great numbers in the fall.  There are 33 species in the US, compared with 2,000 species worldwide.   They belong to the order Matodea, and our most common species is the Northern Walking Stick (Dipheromera femorata).  This species eats the foliage of deciduous trees, mainly oaks.

Their defense is in their resemblance to dry sticks with green legs looking like leaf petioles.  They even have the ability to rock back and forth like branches blowing in the wind.  When approached, they may freeze in a defensive maneuver like deer and rabbits frequently do to avoid detection.  In addition to looking more stick-like, holding still offers other protection as most predators will avoid eating dead prey.  Amazingly, if this fails and something tears its leg off, it can escape and then regenerate a new leg, a very unusual trait among its fellow insects.

Stick insects grow from the eggs laid in leaf litter in the fall.  They grow by molting, the youngest being simply smaller versions of the sexually mature adults.  It is common to find mating pairs such as the ones above, with the male tightly clasping the back of the female.  The reason we find them mating so often is that the male will hang on for days.  This is thought to be a behavior not driven by the male’s excessive lust so much as to prevent other males from fertilizing his female and displacing his gene pool.*

Another trait is the population explosions seen in some years.  In 2008, we saw this occur with stick insects all over our Bull Creek house and trees.  Who knows?  Maybe it was lust after all.

* This behavior and other strategies are discussed further in Olivia Judson's book, Dr. Tatiana’s Sex Advice to All Creation, p. 9.
For more than you ever wanted to know about walking sticks, look at Phasmatodea.com