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.

Sunday, December 4, 2016

Beautiful Scat

Mark Bower sent me these pictures of a small piece of scat (poop for our 5th grade audience) that he found on a dead log about five feet above the ground. If you look closely you will understand why a mycological photographer would focus on this unusual subject. Like much of the world, if you move slowly and look closely, there is a lot of hidden beauty. The tiny hairs with yellow dots arising from the scat are pin molds (Mucorales), possibly Phycomyces blakesleeanus.

 Sporangiosphores of Phycomyces -  Mark Bower
The fungus genus Phycomyces is noted for its phototropism characteristics.  Phototropism refers to the growth of an organism in response to light.  This is best known in sunflowers whose stems and blossoms grow to face the sun.  The spore-bearing sporangiophores of Phycomyces are very sensitive to different environmental signals including light, gravity, wind, chemicals and adjacent objects. One of the most intriguing is its growth avoidance of solid objects.
"Phycomyces also exhibits an avoidance response, in which the growing sporangiophore avoids solid objects in its path, bending away from them without touching them, and then continuing to grow upward again. This is believed to result from an unidentified "avoidance gas" that is emitted by the growing zone of the sporangiophore. This gas would concentrate in the airspace between the Phycomyces and the object. This higher concentration would be detected by the side of the sporangiophore's growing zone, which would grow faster, causing the sporangiophore to bend away." Wikipedia
Mark explained: "I took the pictures on site at VWM. When I looked at them on the computer I was amazed. Went back this afternoon with a spatula and Tupperware to retrieve the poo. However, the water droplets were gone and the home photos were disappointing. Now I have unidentified poop in our kitchen." (Jan, like my wife is a very understanding woman. She would never be upset that he couldn't identify the species of the poo bearing creature.)  

Seed in scat - Bower
As a true scientist he broke it apart to learn more about the culprit which left the gift. The scat was three inches in diameter, dry and firm, and contained small seeds and a tiny piece of gravel inside.
  The only other clue was its placement on top of a stump or raised area.  This is a habit commonly seen with raccoons who apparently are as proud of their poo as our dog is, carefully placing it in a special place for reasons known only to it.  

Raccoons will frequently create a "latrine" where there is scat of various ages.  Whether this is for sanitation, territory marking or just pride is unknown.  If the chosen site for the gifts is around humans, careful cleaning is required.  Raccoons can carry a round worm (Baylisascaris procyonis) which can infect humans if they accidentally ingest the eggs.  The MU Extension has information on managing problem raccoons.

Looking for some light reading?  Try The Hidden Dangers of Botany, suggested by Christine Chiu.

Thursday, December 1, 2016

Finding EAB in Winter

Stripping of ash bark by woodpeckers while seeking emerald ash borer larvae; this foraging damage is called “blonding.” Photo: Jennifer Forman Orth,MDAR
The Missouri Department of Conservation is looking for help from birdwatchers, hunters and others of us out in the woods in watching for signs of Emerald Ash Borer (EAB).  EAB kills ash trees in the genus Fraxinus, which includes the commonly planted green ash and white ash.  It has been reported in 30 Missouri counties but none reported in Southwest Missouri so far.

You may have seen photographs of the typical small D-shaped hole the insect produces.  More dramatic are the tracks under the bark after the tree is dead.  Since EAB usually starts high up in the tree, these finds are hard to see.  Robbie Doerhoff, Forest Entomologist with MDC shared some more signs for bird watchers and other of us out in the woods to be looking for including "bark blonding," a new finding to me.  To quote Robbie:
"So, what is bark blonding? Woodpeckers searching for insect larvae inside trees often pop off the outer bark (see EAB website). On ash trees, this feeding activity reveals a white inner bark that is highly noticeable. Ash trees with bark blonding may not have EAB, but it is certainly worth reporting these trees for a closer look by trained foresters."

Ash bark blonding (L)

Woodpecker damage with blonding (R)

Ash bark - click to enlarge
However, first you need to be able to identify an ash tree, a little harder with the leaves off this time of year.  Look for gray to brown bark with interlacing corky ridges forming obvious diamonds.  Another clue, useful when looking for morels in the spring, is looking for trunks that split into two main branches10-20 feet above the ground.  Finally, look at the branches.  Ash tree branches are opposite like maple trees but with this more distinctive bark.

The Birdwatcher's Guide to Holes in Trees has more pictures and information.  If you find suspicious signs on an ash tree, report the tree locations using the online form at eab.missouri.edu. They are most interested in reports from new counties where EAB has not yet been found as shown on the map below.

Friday, November 25, 2016

Another Fuzzy Orange Gall

For some reason, when I saw this gall I immediately thought of the recent political campaign.  At a distance it looks like hair but close up (below) it is more fuzzy strands.  It was attached to the center vein of a white oak leaf.  I had recently written about Fuzzy Orange Galls and it didn't look like the spiky Callirhytis furva.

Not hair on closeup - definitely a leaf gall
I put the pictures on Bi-State Bugs and got a rapid response from Charley Eiseman who asked if it was on white oak.  Since it was, he explained "Then it is Andricus quercusflocciCallirhytis furva would only be on hosts in the red oak group."

Galls are identified by the species they appear on as well as their individual appearance.  Looking for information on the cynipid gall wasp C. furva contains is an exercise in frustration.  In this case, Bugguide references a 1911 book, California Gall-making Cynipidae: With Descriptions of New Species by Mary Isabel McCracken which you can download for free.  The description:
"Gall -  Brown elliptical, thin-walled, surface reticulate and covered with a rusty brown mat of fibers, two to many balls on a leaf, lying adjacent or strung along on the midrib, usually beginning at the base of the leaf, at least 1/2 mm in diameter.  Persistent, falling to the ground with the leaves in the fall.  Adults emerge in the breeding room in March."
Identification in 1911 required detailed descriptions compared to today when even a 5th grade WOLF student has a camera (now called a cellphone) to compare with pictures online and we can even send the question to a world-class expert with an answer in minutes.  Inaturalist and Project Noah can help you identify galls by pictures, and commercial photographers are happy to sell you their images for publication.  Mary Isabel McCracken would be so jealous.

Gall cut open - REK
Zipcodezoo.com has links and says that "More than 150 species and subspecies of Andricus have been described" but none of these describe or picture the little wasp that has no findable photos on the web. 

Somehow it is reassuring that in this day of instant information, Snapchat, Wikileaks, and the hacking of the Internet, this little wasp can remain photographically anonymous.

Thursday, November 24, 2016

Liverworts Anonymous

Green things that grow on rocks usually raise the question "Is that moss?"  At that point we all look at each other and shrug.  Gala sent me these pictures from a late October trip described below.  A few days later Chris Barnhart sent me photographs of a liverwort and I decided to dive into the subject of which I know nothing.  First from Gala:
"Oct 27- Allan, Jennifer and I took a field trip to Peck Ranch in hopes of viewing elk. The day was beautiful and a warm 80°, perhaps too warm for critters to be out and about at mid-day ...no elk to be found. Regardless of the lack of elk sightings, we had a lovely day and decided to stop at a low water bridge and hike the stream bed. It was a losing stream with several remnant pools and a few sections of flowing water here and there. Among the fall leaves, we noticed the vibrant green of some interesting plants clinging to large rocks, we stopped for closer inspection. 
The plant looked a little "fern-like" but was close-growing on the rocks, not upright or loose. I pulled at the top of a "leaf" and discovered tiny "roots" attaching the plant to the rock itself. If you zoom in, it looks like interlocking scales or plates.  We took some photos for later identification, that's where Bob comes in...!"
I sent the photographs to Nels Holmberg for identification.  He responded that "This is Conocephalum salebrosum (formally Conocephalum conicum), the Great Scented Liverwort.  It is common along streams. And it does have a robust aroma."  Most of the information such as this detailed site is under the C. conicum name.

E. pardella moth - Wikipedia
It is also called the Common Mushroom-headed Liverwort, or Snakeskin Liverwort.  It gets its snakeskin name from the tiny hexagonal scale-like surface.  C salebrosum is the largest of the thalloid liverworts.  In the Pacific Northwest it is the host plant for the Epimartyria pardella moth.  The Conocephalum genus has two known species and a worldwide distribution. 
Day before the rain - Barnhart
A few days later Chris Barnhart sent me pictures of a liverwort outside his office.  There was a dramatic difference before and after a rain.  Nels Holmberg tentatively identified it as Asterella tenella, a thaloid liverwort which usually spreads out one plant deep.  Since this was in a thick pad he sent it on to the Missouri Botanical Garden where the ID was confirmed.

Day after a rain - Barnhart
A. tenella - Barnhart
When viewed close up, you can see the purple scales growing on the tips of the thalli.  This description, "Plants green with purplish undulate margins and purplish underside; branching dichotomous, rarely with intercalary branches" only gets more dense as it goes on.  This is a reminder that understanding bryophytes requires a whole new language.   

Even the the question "Is that moss?" can be complex.  The overall physical similarity of some mosses and leafy liverworts means that confirmation of the identification of some groups can be performed with certainty only with the aid of microscopy or an experienced bryologist.  Help is on the way when Nels comes to our March meeting.  Until then I will probably dabble around the edges rather than plunge deeply into the field of bryophytes.

An Introduction to Bryophytes

Friday, November 11, 2016

Nature for Fun

"Now this is fun"
From time to time I receive interesting stories about nature that are worthy of passing on, new discoveries or just for fun.  I will be adding some of these unrelated links at the bottom of future blogs.  There will be no extra charge for this feature.  Here is your starter dose.

Meet the Bird that Filled an Antenna With Acorns
Thanks to Shanholzer.

Wednesday, November 9, 2016


A few years ago our neighbors brought us several gigantic leaves from a tree up on top of our hillside.  They wore them draped over their heads like huge sun hats.  This was our introduction to Paulownia, an Asian invasive species.  Barb isn't smiling, that is actually a grimace.

This is the Princess Tree or Empress Tree, Paulownia tomentosa, a tree that you can love and hate at the same time.  Let's start with the love.  It is planted as an ornamental in gardens and parks.  It was even awarded the Royal Horticultural Society Award of Garden Merit in England.  It has large, colorful and fragrant flowers.

Paulownia flowers - Wikimedia
It is rapid growing, a pioneer plant adept at growing on barren ground.  Its massive leaves can enrich the soil and while it grows tall (35-80 feet) rapidly, it doesn't tolerate shade of the taller trees that in China will grow more slowly and eventually replace it.

There is now a growing market for Paulownia as a rapid growing soft wood that carves easily and can be used in plywood.  It is said to be strong and lightweight, "ideal" for surf boards and wooden boats.  It is also being touted as rapid growing carbon dioxide sink.  The sites selling it talk about the ease of the trees spreading and the fact that stakes cut from the stems readily root.  Can you spell invasive?

One year growth - click to enlarge

"Rapid growing" is like calling Moby Dick a big fish.  I cut the three trunks of our specimen last fall and was amazed to return this year and watch the growth.  The young trunks are flexible and hang in a curve with the weight of the leaves.  Richard Herman joined us and was able to pull the 12 foot high plant down for pictures.  The picture on the right is one of the trunks after we cut it off at ground level without spraying the stump last fall.  You can just make me out in the hat in the lower right hand corner.

The first few years Barb and I battled on the fate of the tree.  I wanted to leave it alone at least until we saw blossoms and fruit.  Barb wanted it cut and killed immediately.  We compromised on cutting it when it blossomed, while she told every visitor that saw the tree that when she died they had a sacred responsibility to come to our tree farm and cut it down in her memory.

This year in the spring the tree produced buds and she called in her debt.  With a heavy heart, I cut down the trunks and photographed the results.  The poor buds died before fulfilling their biological mission to "go forth and multiply."

Paulownia stems
Paulownia trunk

This did give me the opportunity to study the wood, which demonstrated how it can grow so rapidly.  In addition to being very soft and light weight, the young trunks are hollow in the center!  As you might expect, this rapid growth is at the expense of strength.  Two strokes of a hand held Silkey Saw halfway through the trunk and it broke off.  

The final question was how did this get into the middle of our timber stand, several miles from the nearest residential yard.  The answer lies in the tiny light weight winged seeds,  These can easily be spread by wind and water.  So are Paulownia trees good or bad?  As usual, the answer is "it depends."