Friday, January 20, 2017

Sweet-toothed Fungus

Ash bolete, with its eccentric stem partially emerging from the ground - Mark Bower
I came across these mushrooms while reading Fascinating Fungi of the Ozarks,*  It looks like a giant clam coming out of the ground but is actually an ash bolete fungus with the catchy name of Boletinellus merulioides. Other sources list it as Gyrodon meluliodes, which I will use, as the abbreviation GM sounds better that the alternative BM.

Ash bolete, cut surface- Mark Bower
GM only occurs with ash trees but unlike other fungi that are either saprophytic (eating dead wood) or mycorrhizal (sharing nutrition with the plant's roots) this one has a sweet tooth.  It typically has an off-center or even lateral stem.  Rather than invading the ash tree for nutrition, it wraps its mycelium into tiny cups called sclerotia which fungi use to store food reserves.  
  GM sclerotia containing aphids  - Mark Brundrett
PF aphid -  Claude Pilon  @Pending
In the case of GM, its sclerotia are protecting aphids.  These are not just any aphids but Prociphilus (Meliarhizophagus) fraxinifolii (PF), the "leafcurl ash aphid."  They are specialists that attack only ash trees. 
They feed on the ash trees and and can cause significant damage. They also produce honeydew that is the source of food for the GM.  In trade, the bolete provides the aphids shelter.  

Exactly how the fungus manages to find the tree and the aphid is unknown but it manages to travel, including to China and Europe, (possibly in an international invasive species exchange program?)  As Mark Brundrett pointed out to me while giving permission to use his photograph above, "I think this fungus may become extinct along with its host tree due to ash borer." On the other hand, it might just possibly survive in its invaded lands.

* Fascinating Fungi of the Ozarks, Mark Bower, 2015.

Saturday, January 14, 2017

The Case of the Case-carrying Worm

Dero (Aulophorus) vaga - 1mm - Linda Bower
I was following correspondence from Linda Bower asking Chris Barnhart for identification help after filming an eccentric worm that appeared to be dragging around a decorated case. Chris recognized that the case was partly made of Bryozoan statoblasts (the oval brown objects with a pale perimeter). Chris Barkau, Graduate Research Assistant at Southern Illinois University Carbondale was able to identify it as Tubificida: Naididae: Naidinae: Dero (Aulophorus) vaga.  I asked Linda to describe her find.

Case-carrying Worms dwell in ponds with Duckweed, but are often missed by traditional collecting methods. They are tiny – less than 1mm. It was difficult to find recent* detailed information on Dero vaga, also called Aulophorus vaga. We know that it forms protective tubes by means of a viscid secretion from their bodies. You can watch this video of the worm sliding in and out of its case as it searches for food. It is a fascinating dance you won't see elsewhere, and it is free!
Cut and whole Bryozoan colonies - Click to enlarge - MDC
The Case-carrying Worm is interesting enough, but combined with Bryozoan statoblasts? Wow! Bryozoans (aka Moss Animals) are really animals, but given their appearance, that is hard to believe. Bryozoans are a major animal group, having nearly 4,000 known species and only a few dozen of those live in freshwater habitats. They may grow on any submerged object, such as rocks, roots, and branches. They feed on protozoans, bacteria, and organic matter from the water. They are colonial, living in gelatinous blobs.

Most freshwater species produce resistant bodies called statoblasts that form in response to adverse environmental conditions and provide a means of overwintering. As they grow the statoblasts produce bi-valve shells made of chitin, the same stuff that makes the exoskeleton of arthropods (think insects and crayfish). More detailed information on Bryozoans is at this link.

I have filmed several Case-carrying Worms since this first find and here are three additional videos. Do not resist your temptation – follow these links:
Editor's note: You can bail out now or follow along for the details of the complicated life of D. vaga (or if you prefer A. vaga). These tiny (1mm) worms can be found floating within a mass of duckweed or clustered in the algae of the pond bottom, moving up or down based on the availability of food.  Like all other Oligochaeta (worms) D. vaga is a hermaphrodite. It is capable of sexual reproduction or fission. This was described in an 1899 paper, The Natural History and Morphology of Dera vaga.

The period of sexual reproduction occurs during the first two weeks of July, when the body cavity posterior to the clitellum is crowded with eggs.  Asexual reproduction by fission takes place throughout the year, but most rapidly during warm weather, when it may occur as often as three times a week. Three fission zones have been observed in one individual at the same time.
Click to enlarge

As the animal grows in length, the case which it inhabits is extended, and after fission the two daughter worms divide it by placing their heads together at its middle and forcibly breaking it, each worm then swimming away with one-half of the old case. The fission zone is formed near the middle of some segment, usually back of XVII and in front of XXII. The new head and tail are almost completely formed before separation takes place. The number of somites in the new head is constant, being five, while twelve to sixteen segments are visible in the tail before a second fission begins.
Worms divided by cutting regenerate the missing part, though only enough segments are regenerated at the anterior end to complete the cephalized portion, i.e., the first five. Thus if two are removed but two regenerate, while if seven are taken away only five new segments are formed. At least three or four segments in addition to the five in the cephalic region are necessary for the regeneration of the tail. 
There are detailed descriptions of this Oligochaete available when searching name variations.  

Friday, January 6, 2017

Tool Using Wasp

Ammophila procera the Common Thread-waisted Wasp  -  REK
I have been watching Becky Swearingen's video of a Thread-waisted Wasp preparing a home for her offspring.  It appears to be Ammophila procera the Common Thread-waisted Wasp which we discussed in a recent blog.  It had previously brought a paralyzed insect into a hole it had created.  She goes on from there:
"I watched it as it entered the hole, brought out a little bit of dirt, dropped it and then reentered the hole repeating the process. This went on for some time and then the wasp wandered around checking out small bits of rock – tiny pieces of rock until it found the perfect one. She picked it up, went back to its hole and dropped in in the opening, where it was a perfect fit. The wasp then scuffed some dirt over the covered hole and was gone."
A. procera working on its hole for egg deposit - Becky Swearingen.
In Planet of the Bugs, Scott Shaw describes the evolution of wasps' parenting strategies.  In prehistoric times, the earliest versions (Version 1.0) of wasps were gentle creatures, unless you happened to be another insect. Their tail end came equipped with an ovipositor, a tube which would lay an egg on a victim and the larva would emerge and start to feed.  The next versions of wasp (Versions 1.xx) could deposit the egg through the victim's skin.

Sometime in the late Jurassic period, wasp Version 2.0 came out with modifications to the ovipositor, converting it to a stinger, handy for self-defense as well as killing prey for it to feed upon. Some time around then some wasp's venom was modified to simply paralyze the prey, preserving it alive and prolonging the time its larva could devour the insect at leisure from the inside.

With more time, some wasps began picking up the paralyzed insect and hauling it to a protected place, laying an egg on each one before sealing up the entrance.  Mud daubers stuffed their prey in mud tubes while solitary wasps like our thread-waist wasp used holes in the ground or hollow plant stems.  This would frequently include placing a stone in the entrance as Becky describes.  As Shaw* points out, "Wasps were the first stone tool users, tens of millions of years before the first primate or human picked up a rock."

Don't forget to watch Becky's Thread-waisted Wasp video. 

Planet of the Bugs, Scott R. Shaw, 2014.  This is my favorite book at present, a breezy look at insect evolution over the last 400 million plus years.  It goes beyond anatomy to describe how behaviors evolved in concert with other plants and animals.

Thursday, December 22, 2016

A Loss for Words

from Wikimedia
A beautiful little posting on the blog Tuesdays in the Tallgrass began with this startling statement which should awaken us all to the current state of nature awareness.
"What’s in a name? The Oxford Junior (Illustrated) Dictionary has eliminated some words from its children’s dictionary that name things. Acorn. Willow. Buttercup. Kingfisher–and, other words that are about nature. Adults I encounter no longer seem to have a reference point for common names of plants and other members of the natural world."
Acorn!  Willow!  Say it ain't so!  An article in the New Yorker pointed out their passing to make room for "broadband" and "MP3 player".  Nothing new here,  The 2008 version deleted "moss" and "fern".  The changing of entries to accommodate new words has occurred throughout the history of dictionaries, eliminating archaic words no longer in use, a necessity in all but the most encyclopedic of dictionaries.

BUT, the choice of the words that a child might look up says something to me about our current generation of parents and children.  More important, the target audience for this dictionary are 7 year old kids and presumably the parents who are reading with them.  Are they really going to look up "MP3 player----REALLY?"  And what is more likely to become archaic in the next generation of dictionary, MP3 or acorn?  Can you say "8-track player?"
An acorn, struggling for life - REK
My concern is not with the dictionary itself but in the implications of the changes.  This is a formal recognition by editors that acorns and moss are no longer words a child might encounter!  When our kids lose an awareness of nature, we are all in trouble.  After all,  "Mighty oaks from little acorns grow."

Postscript December 23, 2016
Lisa Berger responded with a followup link which lists more deleted words of nature, but with a charming addition of new (to us) words from the British Isles.   Consider "Crizzle: Northamptonshire dialect verb for the freezing of water that evokes the sound of a natural activity too slow for human hearing to detect."

I think you will find this an uplifting listing during our current trying times.  Check out  24 profoundly beautiful words that describe nature and landscapes,

Tuesday, December 13, 2016

One Tough Fly

As we prepare to survive the Ozark winter, I came across this incredible midge living in semi-arid regions of Central Africa.  Polypedilum vanderplanki is a true survivor.  It lives in tiny transient mud puddles in a region where the dry season may go 8 months without a drop of rain.  Its larvae can survive complete dehydration at high temperatures for months, then revive within an hour to its normal activity.  Its eggs, pupae and adults die in those same circumstances.

Once fully dehydrated, it can survive a whole string of tortures designed by fiendish (or well intentioned scientists) determining the limits to its life.  In a fully dehydrated state it can survive to reproduce in the following Olympic events for durability.
  • 17 years of complete dehydration
  • boiling for 3 hours at 106⁰ C
  • bathing in 100% ethanol for 17 hours
  • freezing at -190ºC for 77 hours.
Recently a cell line from the larva has been preserved after dehydration to 6% of residual moisture and kept for 251 days at room temperature.  When rehydrated it was able to resume swimming and proliferation, while its eggs, pupae and adults die in those same circumstances.

The secret to its success is a sugar called trehalose, as explained in this story in far more detail than I would even attempt.

Saturday, December 10, 2016

Corn is for Popping

Squirrel at a feeder - hors d'oeuvres before hitting the bird feeder - REK
Winter is the time for popcorn and hot cornbread with butter and syrup.  Some might even like a sip of a good distilled corn mash.  Maybe even a bowl of corn flakes.  But most important, corn isn't for wildlife, although a racoon in your fresh corn field might disagree.

Let's start with deer.  In Feeding corn to deer could be death sentence, a deer biologist and a veterinarian explain the problem.  For one thing, a deer's digestive tract is not designed to handle high carbohydrate loads.  In winter especially its bacteria and enzymes are tuned to a diet of woody vegetation and a load of corn in the gut acidifies it, killing off its normal bacteria and can lead to acidosis and death.

Winter time feeding isn't even necessary.  Jerry Feaser, a deer biologist, explains:
“By late fall, deer instinctively reduce their food intake and continue to do so through most of the winter,” Feaser says. “During that time deer rely heavily on fat reserves and their ability to conserve energy.  In fact, a 1984 Pennsylvania study found that deer could survive a least a month with no food at all. During winter, deer lose 20 percent or more of their body weight by burning fat reserves. They are well adapted to survive the many stresses that winter presents."

Feeding deer is never a good idea and in New York it is actually illegal.  It is actually banned in 29 Missouri counties.  Unlike putting out food plots where the deer are spread out browsing, a feeder concentrates individuals in close proximity which can increase the spread of disease like CWD and blue tongue as described by Jim Low of MDC.  You may also do Bambi a disservice in our area when hunters gather outside your gate, waiting to take their pick as deer movement becomes predictable.

What about squirrels?  We have fed squirrels corn in the past to keep them away from our bird feeders.  Yeah, like that is going to happen!  It turns out that field corn is not only not a good food for them but it can have a toxic mold.  Unless they are eating the siding of your house and your feeding them corn has ulterior motive, best not to do it.
Bears at the feeder -

Finally, deer feeders are rarely marked plainly enough to keep near-sighted bears away.  Most corn feeders are around your house so you can see visiting wildlife.  Encouraging a bear to come in for a free meal may be thrilling the first time but once they get addicted, the thrill is gone.  "A fed bear is a dead bear," is still true and you don't want the blood on your hands.

It is time to stop feeding wildlife which has managed to get along without us for hundred of thousands of years.  Birds, OK, when it doesn't attract bears in the wild.  I like seeing wildlife up close as much as you do.  But it just isn't worth the price. 

* Hunters will want to read this from Field and Stream.
Good News- Suburban living may reduce the risks of cancer and lung disease

Tuesday, December 6, 2016

Green Bottle Flies

Bottle fly on the deck  - REK
I saw this green bottle fly on our deck last summer, not where I would usually expect to see it.  It is more commonly found on dead animals, sometimes swarming in an egg laying frenzy.  It is one of many species in the Calliphoridae family, known as blow flies, a term dating back to Shakespeare.  While not exactly warm and fuzzy insects, they play an important role in nature.

A few hours after laying out a dead rat - REK
They will arrive rapidly, usually the first insect to find a corpse.  Their association with dead animals is linked to anautogeny, the requirement of the female to feed on a particular meal before her eggs will become fertile, much as the female mosquito that feeds on us.  In the case of the blowfly, she gets the protein load needed to produce viable eggs and will begin laying eggs within two days.  This is convenient one-stop shopping as she then is able to place the eggs directly on the carcass that will feed her young larvae.
L. sericata on a dead wood rat - note larva behind wing-  REK
After emerging from the egg in 8 to 24 hours, the larvae will go through 3 instars in a predictable fashion.   The speed of growth and instar progression is temperature dependent.  As the maggot mass together, their salivary digestive enzymes break down tissue and the temperature in their vicinity can reach over 100⁰ F.   The predictable  progression of instars is a tool used by forensic entomologists to determine length of time a body has been dead.  In addition, in a closed crime scene, finding blow flies suggests that the body has been moved.

Life is not easy for a young maggot.  The competition for a dead body can be fierce.  When the larva isn't providing extra protein for scavengers such as vultures and coyotes, it is vulnerable to mites that are carried to the body by carrion beetles, thus eliminating competition to the beetles' larvae.  If it survives through the third instar, it will then crawl off into the soil to pupate.  I assume that if it is in a closed room with a tile floor it is out of luck.

Green Bottle Fly on a toothpick - REK
They have more than one role in nature.  Adults take nectar and have been used as pollinators of onions, cabbages, broccoli, kale, and also other Brassicaceae where they are more efficient that bees.  (Mothers, this is probably more science that you want to share with your children while getting them to eat their vegetables.)

L. sericata larvae  - Joseph Berger CC
Finally, the bottle fly larvae (medical maggots) were used in the Civil War to debride tissue from wounds and are still used occasionally today.  Since they only feed on dead tissue, medical maggots raised in a sterile environment can clean out inaccessible necrotic tissue, avoiding damage of opening a deep wound.  Their enzymes digest the dead tissue and stimulate granulation tissue for healing.

So what is not to love about Green Bottle Flies?  They return dead animals to the soil,  clean wounds and pollinate our vegetables.  Just forget what I said about kale.

More Green Bottle Fly details are here.