Wednesday, June 30, 2010

Bison

The study of the relationship between the native Americans and the bison is an excellent example of the sustainable use of resources.  On the other hand, the near extinction of bison brought on by market hunting and social pressures in the 19th century demonstrates the need for conservation and the results of restoration of threatened species.   A team of our Master Naturalists, trained by our mentor Jay Barber, are taking this lesson out to area schools.
Bison roamed the soon to be United States and southern Canada for thousands of years prior to man's arrival.  An estimated 60 million traveled in massive herds, thriving on the prairies between the Rocky Mountains and as far east as New York.*  When they first encountered man, he was armed only with spears and the atlatl, but later with the development of the bow and arrow, man became a more serious predator.
The Native Americans initially depended upon an unending supply of bison for all their needs.  Bison were their Walmart, providing food, clothing, shelter, and utensils.,  Virtually every part of the bison was used, including buffalo chips, the main source of fire fuel on the grass covered prairie.  Until the development of agriculture after 2000 BCE, hunting bison and gathering plants was their way of life.
Lewis and Clark and others were amazed at the numbers of bison and relied on them for much of their food in the move west.  Then in the 1850's, hunting them as a sport became popular among the "new Americans".  Building the railroads created the need for meat for the workers and market hunting became a new industry.  New hide tanning techniques led to a demand for buffalo hides in Europe the completion of the railroads provided the transportation, leading to the wholesale slaughter of Bison.
Finally, the discovery of buffalo tongue as a delicacy back East led to the slaughter of animals which were left tongue-less on the prairie, hides and all.  These developing markets led Native Americans to join in the slaughter in trade of guns and other goods.
The economic pressures did what 10,000 plus years of Native American hunting pressure had never come close to creating- extinction.  By 1873, bison were on the verge of extinction.  From 60 million, their numbers dropped to an estimated 400 on the North American continent.  Changing political philosophy and increasing public awareness finally created conservation efforts.  Over the next 50 years the restoration of token herds, led to the bison we see today.
The westward growth of our nation with expanding agriculture would have eventually destroyed the way of life of the bison, even without the hunting pressures.  The story of the bison is more dramatic, but the same story almost played out with deer and turkey.  Hunting pressure from native Americans and settlers in the 1820s decimated those populations until the establishment of game laws and the Missouri Department of Conservation led to their thriving again in the state.
This was not the first episode of extinction of a large mammal by man on this continent.  Smithsonian Magazine this month features an article on the mammoths and the mastodons of North America.  They were separate breeds, frequently confused in the public minds.  Their extinction occurred at the time of the arrival of man across the Bering Land Bridge and the ending of the last Ice Age.  There is considerable debate about which factors caused the extinction.  What ever the cause, as I pointed out in the March 12th blog, megafauna in general "had a bad habit of disappearing around the time of human arrival, be it West Indies about 6,000 years ago or Australia 50,000 years ago."
We know that they were hunted by early Native Americans.   Mastidon State Park just south of st. Louis is the site where archaeologists first discovered a stone weapon with the bones of American mastodons. This was the first solid evidence of the coexistence of humans and mastodons in eastern North America.  The whole story is found here.
By telling the story of Native American use of the bison, near extinction and restoration to the WOLF School (right) and any other area schools, we spread the message of conservation and maintenance of our natural resources.
* The best single Bison resource we have come across is The Time of the Buffalo by Tom McHugh.

Sunday, June 27, 2010

Invasives Species Have Natural Enemies

When faced with advancing invasive species, it feels like we are alone in the battle.  We have to remember that where they originally came from, they coevolved with enemies that kept their numbers in check.  This fact offers us some hope.
Invasive thistle is a good example.  Aside from a few native thistle species, the rest you see were brought to this continent to beautify gardens.  They are beautiful and butterflies love them, but cattle don't.  Even vegetarians are disturbed when they take over a prairie.  With 10,000 seeds per flower head, it doesn't take long.  Canada thistle, Scotch thistle and musk thistle are on the Missouri Noxious Plant list.

There are two weevils which attack the thistle.  The thistle-head weevil is a native of Europe.  After studies to "be sure" that it would not attack economically important plants, this beetle was released in the 1970s.  It can be purchased and placed on flower heads.  A less expensive way is to harvest them from infested plants.  You simply spread a sheet under the plant and whack at the flower heads, which is not only productive but lots of fun.
The rosette weevil , Trichosirocalus horridus, feeds on musk thistle during the rosette stage, killing first-year rosettes.  Thistles have a two year life cycle, and killing the rosette prevents it from maturing and producing seed the next season.  Weevils require time to go through their complete life cycle.  Working in fields without grazing cattle they can reduce the thistle population as much as 95%.  There is also a thistle defoliating beetle, Cassida rubiginosa, and a thistle-stem gall fly, Urophora cardui which damage the plants.


Gypsy moths have pathogens also and the good news is that they catch up to them quickly.  New research reported in Science Daily suggests that where the moth goes, their infecting virus and fungal pathogens show up soon after.
The fungal pathogen (Entomophaga maimaiga)was first reported in 1989 and attacks the caterpillars. Land managers gather fungal spore-containing caterpillar cadavers and spread them to try and control new populations of gypsy moths. The virus (Lymantria dispar nucleopolyhedrovirus), which was accidentally introduced near Boston in 1906, also infects gypsy moth caterpillars and is used in a spray by the U.S. Forest Service to control the moths in environmentally sensitive areas.
The new study suggests that land managers efforts to introduce these organisms may be unnecessary.  "Once their traps caught more than 74 moths each in one year, there was a more than 50 percent chance of finding the fungus in that area in the following year.  When more than 252 moths were trapped in a year, there was  more than a 50 percent chance of finding the virus the next year."

If we could live for a few more centuries, we would probably find some semblance of balance from these invaders- and most likely many new crops of invasive species.

Friday, June 25, 2010

Janet's Cat

Janet Haworth found this beauty in her backyard.
While trying to identify it, I discovered a website that shows lots of promise in identifying caterpillars.  Discover Life displays these larva by color, size, etc.  It didn't show our "cat" but as its database expands, the sorting algorithm may become more valuable.
So, back to Bugguide.com, entering caterpillar and paging through pictures, 50 per page.  This is time consuming, not so much from the search but from all the diversions, reading about all the interesting pictures- weird caterpillars, eggs, and cats crawling with parasitic larva of wasps. A cat on the left (Black-waved Flannel Moth was the only other candidate, but its unruly hair ruled it out.  Finally I hit pay dirt with this link which shows what appears to  be Janet's cat.
Cycnia tenera, (Dogbane tiger-moth or Delicate Cycnia) has a wide range from Canada to the Southern US.  Wikipedia says it feeds on dogbane and Indian hemp as well as milkweed.  Each of these plants produces toxic chemicals which deters many herbivores.  Many caterpillars which eat these plants can store the toxins, making them unpalatable to birds and other insectivores.
Janet's caterpillar develops into a white moth with an interesting talent.  Bats have apparently learned not to eat resting or dead C. tenera moths but will catch them in midair, presumably not having enough time to identify them by sight.  The moths emit clicking sounds when the hunting bats switch from search phase calls to approach phase calls.  When handled by the bat, the moth produces clicks and bats are more likely to drop them than mute moths.  Presumably the coded message is "eat me and you will get sick, sucker."
All this and more comes from this Wikipedia link.

Thursday, June 24, 2010

Creation Myths

I just came across Creation Myths by Nancy Gibbs.  This thoughtful editorial concisely bundles the pros and cons, moral and political choices, and ecological issues arising from Craig Venter's recent announcement of "the creation of life in a lab."
I think you will find this an interesting editorial.  See this in time.com.

Wednesday, June 23, 2010

Sericea Lespedeza- Fugitive From Justice

Sericea lespedeza is not on the "Eleven Most Unwanted" list in Missouri, otherwise known as the Noxious Weeds of Missouri.  One of the most invasive species, its absence is due to politics that I won't go into.  However, its failure to pass the legislative test doesn't mean it should be ignored.  It is a major invader of agricultural fields, prairies and even glades such as Rocky Barrens where it has become a major problem.
As described in MDC Online, it was first introduced to the US in 1896.  It was planted in pastures because although it was exotic, it was easy to plant and would grow virtually anywhere (a big red flag for invasive characteristics.)  Two varieties of sericea were developed for improved forage quality and nematode resistance. These varieties were used on highway rights-of-way, dams, and waterways. In the 1930s it was planted on strip-mined land in southeast Kansas and Missouri.  It was used extensively by MODOT and other states transportation departments for stabilizing soil although its root system is a long tap root.

It is avoided by grazing animals, with the exception of the famously omnivorous goats.  Sericea has large amounts of tannins which taste bad to animals (and insects) and interfere with digestion by binding proteins.  If cut for hay, after several weeks the tannins break down and they can be used for feed.
Like many invasive species, its tall prolific branching shades out natural species.  Being very shade tolerant, it can easily invade forested land.  Its lack of palatability means that surrounding plants are more likely to be grazed down, giving it a head start.  It also produces allelopathic chemicals which are released from the roots and leaves.  These chemicals inhibit seed germination and growth of grasses.
Identification information is available at this MSU Website.

If any of you Master Naturalists would like some hands-on experience, call Kevin Hedgpeth with the Missouri Department of Conservation.  He is tasked with spraying Sericea lespedeza at Rocky Barrens and another site and could use the help.  You can reach him at 417-751-3856 or Kevin.Hedgepeth@mdc.mo.gov

Tuesday, June 22, 2010

Assassin Bug Larva

I came across this critter crawling on a friends shirt.  It looks innocent at first glance until you notice the distinctive upward turned abdomen and the curved beak tucked up between its front legs.  This is a larval (nymph) of an assassin bug (Reduviidae), a large family with 7,000 species in the family, most of which will go through 5 larval stages before adulthood.  This looks like a wheel bug nymph, a common bug around our cabin.
Assassin bug larva- Patrick Coin
Reduviidae go through an incomplete metamorphosis in which the first nymph (instar) that emerges from the egg has a resemblance to the eventual adult it will become.  The first instar of the wheel bug has a bright red back (picture from Bugguide) which is quite distinctive while the latter instar (pictured above) shows graying much like we humans.  The final stage of adulthood bring them their wings and sex organs.  This is similar to withholding the driving permit and hormones from a teenager.
The adult wheel bug (Arilus cristatus) is easily identified by the gear-like armor on its back.  Like all true bugs, the mouth parts (mandible, maxilla and labium or lips) have evolved into a piercing beak, called a rostrum. It carries it tucked up below its thorax until swinging it out to stab into an unfortunate prey.  Other true bugs, (Hemiptera for you Latin speakers), such as cicadas, aphids, planthoppers, leafhoppers, and shield or stink bugs use their beak of plants.
On the other hand, Assassin bugs are predatory, feeding off the insides of other bugs.  They have strong front legs which tightly grasp their prey as they stab their beak into it and inject digestive juices.  After these have done their work they are able to suck out their dinner like a high protein milkshake.  Most other insects which use this external digestion process have two tubes, one to inject and one to suck out the contents.  Reduviidae have just one large tube to inject and then slurp up the feast.
Wheel bugs tend to move in a jerky motion, and their brief flights produce a loud buzzing sound.  They may bite humans who handle them, an extremely painful experience producing an open sore that can take months to heal.  If that isn't enough to dissuade you from picking one up, their "bad gas" problem may be.  They have two orange glands beside the anus that eject a foul scent when they are disturbed.
To start using "Reduviidae" in conversations with friends, go to howjsay.com.

Good news from the field!  Cynthia Andre reports that her peach tree has lots of Japanese beetles (no surprise there) and lots of wheel bugs including one which she watched stalking one of the beetles.  This serves to remind us that wheel bugs are considered beneficial.

Friday, June 18, 2010

Project Wet

Today's Project WET was advertised as training for teachers, educators and the odd Master Naturalist.  What they didn't say was that it was also entertainment for older kids, in one case really older.  The session was taught by Jay Barber (the guy with the rose in the previous posting) and Erica Cox, our adult leader and the Director of Missouri Project WET.

Project WET is a nonprofit organization with a global reach, dedicated to the mission of reaching children, parents, teachers and community members of the world with water education.  It gives professional and volunteer educators a wide variety of tools to connect with children K to 12 as well as adults.
We experienced some of the many tools and games.  Being adults, of course, we were more reserved and lacked the element of competition which kids typically exhibit.  (Betting was limited to chocolate bars.) 
Our activities included H2Olympics where we demonstrated the cohesion and adhesion properties of water. An example was guessing how many drops of water could be stacked on a penny before the water would run off and then competing to see which team could pile on the most.  Modesty prevents me from announcing which team won, but the answer is well over 50 drops and less than the age of the oldest member.  (Click on pictures to enlarge)

Another exercise starts with a brim full glass of water.  We then guessed the number of pennies we could add before it overflowed.  Because of the cohesion of water, a high dome of water (called a meniscus- see the penny above) formed long before the first drop ran down the side.  (Notice also in the photo lower right, the cohesive dent in the surface as the penny is held on the surface.)
We ended by creating teaching projects which we used on each other.  This gives a real life feel to how these educators can use the many tools we covered in Project WET.
By the way, did you know that you can power a small model boat in races across the water with small slivers of soap?  You can, but I'm not allowed to tell you how.  You would have to train in Project WET to learn this as well as our secret handshake.  Sorry Barb, I've been sworn to secrecy with a WET oath.

Jay Gets the Rose!

Quiz- What's happening here?  (Click on picture)

  1. Jay has taken up rose gardening.
  2. He was honored as one of 64 Gift of Time selections.
  3. The Bachelorette selected him!

Thursday, June 17, 2010

Bitten by Ants

I just spent 20 minutes sitting on a parking lot studying about ants.  Fortunately my truck is air conditioned although I didn't do much to help global warming.  Don't blame me, blame NPR.

Fresh Air had a fascinating interview with Mark Moffett who has just released his new book Adventures Among Ants: A Global Safari with a Cast of Trillions, that describes his research of various ant species around the world.  He has been called "the Indiana Jones of entomology" by the National Geographic Society.  If ant studies aren't usually your thing, just take a listen to his entertaining descriptions of ant life, sex, and warfare.
I found the descriptions of ant warfare to be particularly fascinating.  He contends that the only species which conduct large scale and prolonged wars are ants and humans.  Ant species do this as a biological imperative while human motivation is more complex.
He describes the warfare between massive ant colonies when they border on the territory of another combative species.  There is an invasive species of Argentine ant that lives in enormous "supercolonies" including one that extends from San Francisco to the Mexican border.  If you move them into another ant's territory they will fight to the death, while they blend in peacefully when transplanted into an another area of their supercolony.
There are similar colonies in Spain and Japan, leading researchers to conclude that the three colonies studied actually represented a single global super-colony.  The researchers stated that "enormous extent of this population is paralleled only by human society".   Of particular interest, when members of small colonies are exposed to small colonies of ants from another continent they will fight.  However when the experiment is done with ants from the supercolonies, they rub antennae and behave as life long friends.  All of this is much better described by the BBC.
The invasive fire ants that have invaded the Southern United States are described in Wikipedia.(Picture on left)  While many ants bite and then spray acid in the wound, fire ants bite only to hang on while they inject an alkaloid toxin.  The toxin causes a burning pain and can occasionally be fatal to sensitive individuals
"Although most fire ant species do not bother people and are not invasive due to biological factors, Solenopsis invicta, commonly known as the red imported fire ant (or RIFA) is an invasive pest in many areas of the world."  It was introduced by a South American ship in Alabama in the 1930's and spread across the Southern US and now have reached California.
If you are interested in borrowing Moffett's book, let me know, but be prepared for a long wait.  Meanwhile, some of Moffett's amazing photographs are available  at this NPR site.  They are not for the faint of heart and the captions are hard to read but the effort is worth it.  Warning: You may never walk barefoot again.

Wednesday, June 16, 2010

Rotten Log

What do you get when you put together a park, three adults, some innocent kids and a rotten log.  You might think it would be something to walk around.  If the "adults" happen to be Master Naturalists, it is more like big kids helping younger kids break open rotten wood to use a magnifier to look at critters that used to make little girls go "Ugh and Yeach".  The kids jump right in (with an occasional "Yuck!")
Three of our intrepid Master Naturalists volunteered at the Li'l Sprouts event sponsored by Springfield's Master Gardeners.  Carl and Janet Haworth plus Marlyss Simons explored rotten logs with other children of all ages.   Janet reports that
"Many of the kids were so engrossed in their explorations that they did not want to leave the logs for the other fun activities offered! We had a wasp (Editors Note- see below) come visit and lay eggs amid the decaying matter. (Click on picture) We also opened up a centipede nest. Children and parents alike became absorbed in a previously unexplored world.  It was obvious that a great time was had by all, but we're not sure who had the best time; the children, or the MN Volunteers!"
One of the challenges that we face when digging in a rotting log is the paralyzing question from a child- "What is that called?"  The goal of digging in a rotten log with magnifier in hand is to stimulate wonder and curiosity and help the child identify a "bug" as a fly, grub, centipede, or in this case a spider with its egg sack.  Frequently we can't go beyond that level to identify the species.  Back to our wasp- could it be a Bicytres?  Color and shape are similar so it might or might not be.  Resources such as Bugguide.net and various books help but species identification frequently requires advanced training and a good microscope.  Fortunately, the joy of the search doesn't require a degree and we have highly trained people to call on when needed.

Dr. Chris Barnhart sent me this quote which perfectly summarizes the joy of the Master Naturalist at work and play.
“It quite saddens me to think that when I cross the Styx I may find myself… condemned to keep on trying to solve problems…while the amateur entomologists, who have not been damned professors, are permitted to roam at will among the fragrant asphodels of the Elysian meadows, netting gorgeous ghostly butterflies until the end of time.”  -W. M. Wheeler
Editors Note: Jay Barber has identified the "wasp" as a wasp-mimic fly, probably of the Syrphidae.  The key finding is that it has one pair of wings while wasps have 2 pair.  Of course I knew that all along but modest (No, it was ignorance) prevented me from correcting it.  See Bugguide.com.

Monday, June 14, 2010

Millipede Mass Migration

This just in from one of our Master Naturalists:
Has anyone else been experiencing an outright infestation of millipedes at their homes? My folks place and their neighbors the past few days have been swarmed by them. Saturday night the patios must have been covered with thousands upon thousands. They are even finding their way inside, which has become the real concern. I wanted to send out a feeler and see if anyone else is experiencing this and/or knows what can be done to combat them. So far, ant repellent/kill spray works, but the numbers every evening seem to be growing and once the spray dries… they are back on the move. 
Millipedes are detrivores (meaning that they eat dead plant stuff) and are common around accumulated leaf litter, dead wood and therefore yard and garden mulch.  Moisture attracts them, presumable by increasing the breakdown of dead plant materials.  Removing these sites should (eventually) reduce their numbers.
Detrivores are important members of the food chain.  Working in conjunction with fungus, bacteria, millipedes, woodlice, dung flies, and many terrestrial worms, millipedes breakdown organic material to add to soil. Imagine the buildup of tree trunks piled up on the earth's surface up if there was nothing to break them down!
Mass migrations of millipedes are an interesting phenomenon.  They usually occur in periods of drought or excessive rain, either one driving them from their cozy quarters in moist decaying plant material.  Like you and I, they are looking for the most comfortable place to live, and a damp basement or garage may look like Club Med to them in a drought.
Since pesticides have safety concerns and can kill other beneficial insects (bees and butterflies), environmentally friendly measures should be considered first.  From a Clemson University PDF:
"Nonchemical Control: If garden millipedes are occurring in great numbers indoors, it is usually an indication that there is a large population in the area surrounding the home. To control these pests, the most important step is to remove materials that give them shelter in the immediate area around the home. This includes excessive mulch, leaf litter, thick grass, rocks, boards and similar materials.  De-thatching the lawn and mowing closely allows for drier conditions, which reduces the areas where they can live.  Watering in the morning rather than the evening, also gives the lawn a chance to dry before they become active at night.

Try to prevent garden millipedes from entering the house by making sure doors and windows fit tightly, and as many cracks and crevices are caulked as possible. Remember that they may be entering your home from high areas just as easily as low areas.  In most situations, garden millipedes found indoors can be easily removed with a broom or vacuum."
This article from the Missouri Extension has lots of good information, including pesticide recommendations.
"During mass migrations of millipedes, residual pesticide deposits on the soil surface will have very little effect because of the relatively short time of exposure as millipedes move across treated areas. For effective management in these situations, it is desirable to identify the location of the migrating population by inspecting during the night with a flashlight. Look in areas such as outlying grassy and wooded areas. Direct nighttime treatment of millipedes with an appropriately labeled contact pesticide may be needed for several nights in severe cases."
Migrations are time limited events.  Another treatment is waiting them out.  After all, millipedes need love too.
More on Millipedes at Wikipedia  and this past blog

Plants say "I need a drink"

When my wife looks at her plants, she can tell when they are a little thirsty.  So can I, but by the time I can tell they are nearly ready for the compost.  Suppose the plant could tell us when it needs a drink before it got in trouble.
A neat new technology has been developed to let plants tell us when they need water.  A small sensor clipped on a leaf reports it to a computer.  Orginally designed for space missions where 70% of astronauts time would otherwise be spent on maintaining their food plants, it has even more earthbound implications.
Wireless units are now being developed that have the potential to save fresh water.  A sensor on every 10-20 acres of crops could determine a crops water needs, reducing the water wasted on needless irrigation.  Since 70% of fresh water use goes to agriculture, the long term implications are tremendous.

The report with a 2 minute video is on Science Nation.

On another water front using technology to measure tree sapflow, there is interesting research on a tree's use of water from the National Science Foundation.
Some findings of their findings:
  • shaded trees use less water
  • trees in the wetland actually used less water because they tended to be smaller
  • some trees actually used more water early or late in the day, and less during the middle of the day, possibly because they were not getting as much sunlight because they were in the shade of their taller neighbors.

Sunday, June 13, 2010

Tree of Hell

If I were asked to nominate at tree for the "Kudzu of Trees", it would be Ailanthus altissima, the Tree of Heaven.  All parts of the tree were used in Chinese medicine, for conditions including  mental illness, asthma, dysentery and epilepsy.  It is still used in traditional Chinese medical practice.

It was brought to the US from China in 1784 to provide food for silk worms as it had in China.  Like many invasive species, it seemed like a good idea at the time.  The silk proved inferior and the Ailanthus silkmoth, while attractive, was not easily domesticated.

Early on, it was noted to be easily propagated and would "grow anywhere".  As a rule of thumb, when the words "exotic" and "easily grown and grows anywhere" occur in the same sentence, you are describing an invasive species looking for a place to happen.

Over time its aggressive growth and suckering habits became known.  It was the subject of the book "A Tree Grows in Brooklyn",  serving as a metaphor for the ability to thrive in a difficult environment.  Its prolific growth in the cracks of urban sidewalks was the basis of its nickname, the "ghetto palm".

It has alternate, pinnately compound leaves with 11-41 leaflets.  At first glance Ailanthus can easily be mistaken for a walnut, butternut, or sumac.  These trees however have leaf margins with small teeth (except for winged sumac), while those of Ailanthus are smooth.  The leaflets also have a distinctive notch or ear at the base with a gland on the underside.  The leaves and stem have a bad odor when bruised, especially when bruised, giving rise to the name "stink tree".

It is one of the fastest growing tree in the US, capable of growing 3 to 6 feet a year in the first four years of life.  It grows in almost any disturbed soil as an early succession plant but doesn't compete well in established forests. Just a few trees along open areas can spread rapidly into open spaces and fields.

One secret of its success in reproducing lies in its roots.  These sucker freely, spreading out a few feet and then shooting up as new trees.  It also produces large crops of winged seeds which can spread over wide areas.  Another possible factor is ailanthone, an allelopathic chemical which is produces by the Ailanthus roots.  It is a very effective herbicide in laboratory tests, suppressing growth of many plants for weeks when placed in sterile soil.  However, its real life effectiveness has not been scientifically proven.

There is no question however about the ability of Ailanthus to out-compete most plants.  We have found it out in the middle of our 20 acre pasture and even a large collection in the backyard of our beloved MN vice-president.  We need to eliminate it any where we can, but like kudzu, it is probably here to stay.

More information is at Wikipedia.
For methods of elimination see this PCA website.
A full discussion ailanthone is in this PDF.

Saturday, June 12, 2010

Yucca Moth

I was excited to find a yucca moth last week on the first blossom I checked.  Examining over 100 blossoms, I couldn't find another moth.  While the picture of the little white moth may not seem impressive, the back story is.

Many years ago, before Google first appeared- Remember research before Google? - I was searching information on yucca.  We had noticed it was usually present in cemeteries.  Having tried unsuccessfully to to get rid of a yucca in our yard, we thought it might have been planted in cemeteries in the past as a symbol of eternity.  I contacted an expert,  John Richard Schrock at Emporia State in Kansas and he told me the story of the yucca moth.
He mentioned that neither the moth or the yucca can survive without each other, a relationship called obligate mutalism.  I have been looking for this tiny white moth on our yucca plants ever since. The story of the relationship is briefly outlined in the NBII Website.
The relationship between the yucca moth (Genus: Tegeticula) and yucca plant (Genus: Yucca) is believed to have begun at least 40 million years ago and is one of the most cited examples of co-evolution. The yucca plant requires pollination by the yucca moth and moth larvae, in turn, require developing yucca seeds for food - a relationship known as an obligate mutualism. This is actually one of the few documented cases of active pollination because the moth purposefully places pollen on the plants' stigmas. The female yucca moth has specially adapted mouth-parts used for pollen handling. The moth drags its tentacles across the yucca's anthers and collects a large amount of pollen, which the moth then forms into a sticky ball and carries it between its tentacles and thorax. This pollen ball is very large - often made of nearly 10,000 grains of pollen - and can constitute up to 10% of the moth's weight. After collecting the pollen ball, the moth flies to a different yucca plant to deposit its eggs. The moth deposits its eggs in the flower's ovary and uses its tentacles to scrape the pollen ball onto the top of the yucca plant's stigma, pollinating the yucca plant. The moth then climbs to the new flower's anthers and collects pollen, and repeats the entire process.
This is just the beginning.  As Schrock describes it in the Kansas School Naturalist:
When the petal fall away, the seed pods develop, a sure sign that the moth had been there.  small gray-to-pinkish yucca moth caterpillars may be feeding anywhere in the core of the seed rows. If they burrow toward the end and run out of food, they bore sideways into another locule or across a carpal wall. Often an outside constriction in the pod reveals their internal consumption of seeds. 
When the larvae are mature, they excavate an exit burrow to the surface of the pod, although they may continue feeding for a time. When they completely chew through the surface, they leave an exit hole or scar.
From here the cycle becomes more complex.  A step by step description including lots of pictures is available at Waynesword
including this picture of a seed capsule of Yucca whipplei in October showing the larva of a yucca moth (Tegeticula maculata) inside its feeding cavity in one of the seed chambers.
The Kansas School Naturalist article describes colorful history of the discovery of this moth-yucca association.   
The unusual role of the yucca moth was discovered in 1876 by a Missouri entomologist named C. V. Riley.   He was a writer for the Prairie Farmer, and later started the magazines American Entomologist and Insect Life. He became State Entomologist of Missouri from 1868 to 1877, and became "Chief in Entomology") in the United States Department of Agriculture in 1878. 
Riley was an avid advocate of evolution and traveled to England to meet Darwin. Darwin was particularly interested in Riley's understanding of insect mimicry, a biological phenomenon only understood in the light of evolution. Riley also corresponded with Alfred Russell Wallace (co-discoverer of evolution by natural selection) and Henry Bates (of Batesian mimicry).
The whole story of the rest of the life cycle, including the history and pictures, is available at this link.  I would highly recommend it as entertaining reading.
Postscript from Richard Schrock:
"I live on Yucca Lane...it was by accident, no calculated move.  And I planted yuccas all along the Lane...people say "you grow yuccas" and I correct them: it is a yucca moth farm, perhaps 2000 head on a good year.   The tough part is keeping the ugly pods on through the summer so  the larvae can develop.  Most people want you to cut them off after they flower and that of course dooms the moths.
This has been a late year, with the male moths emerging before the yuccas were in bloom.


Note: Another obligate species found all over the yucca in early summer is halticotoma valida.

Friday, June 11, 2010

Jumping Leaf Galls

In case you missed it, Francis Skalicky had an interesting article on Jumping Oak Leaf Galls in the News-Leader.  A tiny wasp lays it eggs on the leaf, causing ugly browning and shriveling of the leaf but no permanent damage to the tree.  They hit the news because of a larger than usual infestation this year.
According to the Minnesota DNR jumping oak gall wasp is Neuroterus saltatorius, a much more serious name. "Larvae have chemicals in their saliva that stimulate the oak leaf tissue to form the yellow blister-shaped galls. As the galls mature, they are released from the leaf and rain down onto the soil. The galls bounce around until they become lodged in the soil and they overwinter there."
The larva wiggling to free themselves from the gall produces the jumping action.  You can see the galls dance on Youtube.  For a massive overdose of information on these galls, check out the California's Amazing Jumping Galls page.
I was completing this blog when I accidentally stumbled across the MDC Blog on the same subject.  As much time as we spend with MDC, it is a little embarrassing to only now find this Fresh Afield blog that has been in existence since August, 2007!  The blog runs interesting stories about twice a week and I have added it to the home page "Links" so you can follow it regularly.

Speaking of galls, did you know that Alfred C. Kinsey of sexuality behavior studies fame got his start studying galls?  I have been telling you that galls are sexy.  See Confessions of a Gall Hunter.
 
Note:  I have also added Waynes Word to the Links site.  It is a site to browse of interesting reading on biology, botany and has lots of pictures.  Stay away unless you have time to burn!

Wednesday, June 9, 2010

Its the CO2, Stupid!

Today's News-Leader has an interesting editorial by Dr. D. Alexander Wait of the MSU Biology Department discussing the effects of rising carbon dioxide (CO2).  We hear lots of debate on whether there is global warming and if so, is it a natural cycle or due to carbon dioxide accumulation, or both.  Did you know that CO2 was identified as a greenhouse gas in 1859?
In May 1859, six months before the publication of On the Origin of Species, Irish physicist John Tyndall proved that some gases have a remarkable capacity to hang onto heat, so demonstrating the physical basis of the greenhouse effect. Charles Darwin had journeyed round the world and ruminated for 20 years before presenting his inflammatory ideas on evolution. Tyndall spent just a few weeks experimenting in a windowless basement lab in London.  - From newscientist.com.
Lost in the noise of the argument over global warming is the fact that the rising levels of CO2  in recent years has many other effects on the planet.   Dr. Wait's article mentions a few which are particularly interesting.  Although CO2 is used by plants to photosynthesize energy and subsequently release oxygen, too much or too little of anything can be a bad thing.  While many trees and plants may grow faster, corn's photosynthesis mechanism is all ready saturated with CO2 and can't grow any faster.  Unfortunately many weeds thrive and can outgrow crops.  Worse yet, increased CO2 concentrations produce a more potent poison ivy.
"Weeds of crop plants often respond to a greater degree with increased growth than do crop plants, which results in greater amounts of herbicide applications to optimize yield.  Protein content of many crop plants has been shown to decrease when the plants are grown at elevated C02. Finally, recent research with soybeans indicated that increasing concentrations of CO2 are inhibiting resistance to pests such that any potential increases in yield would be more than offset by pest damage."
If global warming advances, we won't see rising sea levels in the Ozarks.  However, atmospheric changes would likely affect growing seasons, plant composition and eventually the lives of insects and animals who depend on them.
Even if there is no effect on global warming, ocean acidification affects us indirectly.  Reduction in coral skeletons can ultimately reduce the coral reefs.  Decreases in marine algae and free-swimming zooplankton can reduce the volume of commercial fish and shellfish while the growth of human population increases demand.
This is the only planet we are leaving our children and their offspring, so we had better take good care of it.  This political message is brought to you by Thomas Jefferson.  "The earth belongs in usufruct [trust] to the living ... no generation can contract debts greater than may be paid during the course of its own existence." Time Magazine editorial.
Carbon dioxide accumulation is the disease; global warming is a likely symptom.

Wednesday, June 2, 2010

Giving Fish a Hand

Big catfish like this are coming back, thanks to regulations from MDC.  In the 1800s, 100+ pound catfish were common reported.  Unrestricted fishing depleted the stock since then.  Altering the river channels for flood control and commercial river traffic and heavy harvesting over the last 100 years has kept catfish from reaching their full growth potential. Recent management efforts have made large catfish more common. Our hope is that, one day, 100-pound catfish may be fairly common again.
Handfishing, called noodling, has been illegal since 1919 in Missouri.  Leaning over a bank or wading in a shallow stream, the fisherman reaches into the fishes mouth and pulls it out.  This is an effective method of catching big catfish in the summer while they are on the nest, a period in which they ignore bait and traditional fishing methods.  See the video.
Noodling has a long history described in the MDC article on catfish.   Noodling selectively removes large, sexually mature fish from their nests, leaving the eggs unguarded and therefore reducing the numbers of new catfish.  Large catfish, like many other species are the most successful at reproduction.  By prohibiting noodling, we gave the species a hand and large catfish began to appear again.  Fishing regulations help insure that the fish population remains stable for fishermen in the future.

Not all fish need a hand from humans.  The current National Geographic describes a new species of fish with hands.  Nine species of Pink Hand Fish have all been found in the shallow waters off of Australia.  Only four specimens of this particular four-inch long species have been found.  They use their "hands" to walk along the bottom rather than swim.

The hand fish are completely different from the Walking Catfish  that were dramatically reported in the press in past years.   They are native to Southeast Asia where they thrive in stagnant water with low oxygen levels.  Recently they have been brought to the US where they inhabit ponds and ditches that are low on oxygen, frequently coming to the surface of grab some fresh air.  When conditions are too bad for survival, they can "walk" across land for some distance to find a better water source.  They "walk" by wiggling on land while using their pectoral fins to stay on their belly, as seen in this video.