Friday, December 27, 2019

Red Velvet Mites




Surrounded by snow and ice, I was warmed by looking back at these pictures from May.  I had been hiking through the riparian plantings and took some pictures of bedstraw or cleavers (Galium aparine).  Even if you don't know the name you have probably picked up some of it tromping through the fields or woods.  Unlike many annoying seeds, these are easily removed.


This weedy plant probably sets the record for the most common names of any organism, including cleavers, clivers, bedstraw, goosegrass, catchweed, stickyweed, sticky bob, stickybud, robin-run-the-hedge, sticky willy, sticky willow, stickyjack, stickeljack, grip grass and velcro plant.  It is used by some as a medicinal poltice, infusion or tea.  The tiny sticky hairs have been adapted to straining milk and create stable shaped mattress ticking.  The fruits can be dried and roasted as a substitute for coffee.

This cleaver above also served as a pedestal for a red velvet mite ( RVM}.  Mites are arachnids as are spiders, harvestmen, scorpions and the ever popular ticks.  Like ticks they have six legs in the first instar, then graduate to eight legs from then to adulthood.  RVMs are members of the Trombididiidae family of mites which gives us several thousand species to choose from.  The larvae of a few species are our familiar blood-sucking chiggers.

Most RVM are not chiggers and it is hard to find good reputable photographs of real chigger mites. There are several species with the blood-sucking habit, the most common being Trombicula alfreddugesi.  Their larva sticks its  proboscis into our skin and injects digestive juice which hardens into a tube called a stylosome, the source of the itching inflammation as described here by Missouri University.

The Bug Lady gives an interesting description of their love life as the male deposits his sperm on a leaf and leaves a silk trail to lead a female to his gift.


Adult RVMs are our friends, consuming insect eggs and small insects on our plants.  With so many different species to choose from, it is unlikely that our friend here is a chigger parent, but we will never know.  

MDC has more information at this link.

Friday, December 13, 2019

Fungus Beetle


Anyone who has hiked a few of our Ozark forests has likely seen these bracket fungi growing like shelves on dead or living trees.  They are called Trametes aesuli now, but the books still call them Trametes elegansThey are tough, leathery and hard to break off the tree.  These are hardened members of the polypore group of fungi.  We collect them for WOLF School students to paint on.

This is a great example of nature's recycling.  Trametes fungus species grow on trees which have some dead tissue, a process called sap rotFungi send enzymes out of their fine hyphal threads to break down the wood and digest the cellulose, a hard trick for anything that has legs.  Even termites depend on microorganisms in their gut to grind the cellulose into something they can turn into energy.  The hard fruiting bodies of these polypores have nutrition that few legged creatures can use.  This is where fungus beetles enter the picture.  These species are obligate fungivores (fungus-eaters), meaning that their specialized digestive systems can only digest fungi.  A prime example are the Neomida bicornis below.
Neomida bicornis found in bracket fungi - REK
I was recently surprised to discover that T. elegans is the main course in the diet of Neomida bicornis.  I stored several hard dried fungi in a sealed plastic bag for future artists and when I opened it six months later they were riddled with holes.  In the bottom of the bag there was lots of powder as well as over 100 little black dots.  On closer inspection they were fungus beetles that had eaten their fill before dying of dehydration and old age.

 

The WOLF School students made another discovery while examining the beetles under the microscope, a beetle larva that had been hidden in the frass.  It has been dried for months and I can only find these photographs of the larva in their living state, so I can only assume that it is also N. bicornis.

Neomida bicornis - REK
Neomida  are strictly fungivorous (fungi-eating) beetles of the Tenebrionidae family.  They bore into the hard conks of Polyporales hosts.  Zookeys states that there are approximately 50 species of Neomida beetles world wide.  For anything that is science you can find experts immersed in the chase. Here are some of their identifying features:
"Members of Neomida are diagnosed by the following features (taken from Triplehorn 1965): antennal club loose and with seven antennomeres; eyes emarginate anteriorly close to antennal insertions, forming a lower portion at least twice as long as the upper portion; head of males usually bearing horns or tubercles on frons or clypeus, or both; prosternal process convex; elytral punctation seriate; basal tarsomere of hind tarsi short." Zookeys
  Katja Schulz
The Neomida bicornis are cute by any 5th grade WOLF School definitionBicornis means (two-horns), referring to the male's head decoration.  Only they know what purpose they serve.  In the deep south they sport an orange pronotum, a trait that disappears as they are found further north.  The beetles are a metallic blue-green in life but our specimens are contracted by dehydration with their pigment broken down with age.  Left in nature they too would be recycled by bacteria and fungus, just like we all are, completing the circle of life.
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Even tiny 3mm beetles can carry smaller mites.  See this photo by Tom Murray!

Wednesday, December 11, 2019

Fungus on Poop






I We don't usually feature a little blob of what a WOLF student would describe as poop, but this picture was sent to me by Mark Bower because of the tiny white filaments in the middle.  The tiny yellow dots are the mushroom-like fruiting bodies or sporangiophores of a pin mold named Phycomyces blakesleeanus, PB for our story.




Mark has taken me on macrophotographic journeys through his lens regularly, but this one is especially spectacular.  The sporangiophores appear perfectly round closeup.  The thin stalks are a different species of pin mold and the clear globules are droplets of dew.

I did not expect to find much additional information on a little pin mold but PB turns out to have a sizable scientific audience.  A 2018  New York Times article describes how it borrowed from ancient bacteria to defy gravity.  "It can respond to wind and touch, grow toward light and detect and navigate around objects placed above it. It senses gravity too — with crystals that move around inside single, but giant, elongated, spore-containing cells that resemble Truffula Trees."  Scientists say the fungus developed its well-known sensing abilities following an ancient genetic transfer between its ancestor and bacteria it encountered.

P blakesleeanus zygosporangia
The PB sporangiophores emit an "avoidance gas" that lets them expand and yet avoid solid objects without touching them.  The science behind this is described in this Wikipedia article and is too dense for me, but it does have this cool photograph of the PB's sexual structures called zygosporangia which resemble insects.


Starfish stinkhorn from Tasmania - Aseroe rubra

By now you may have detected a faint unintended theme of odors beginning with the poop above.  On a less scatological note, Mark has just put together a book of his photographs of the Fungi of Tasmania.  Even if you don't dig mushrooms I think you will be amazed at the photographs, such as this starfish stinkhorn.  There I go again!

You can download the PDF of his book here.

Saturday, December 7, 2019

Grapefern



Hiking along the Mail Trace Road, Barb spotted a solitary green fern poking out of the drab floor of dried leaves.  It had what appeared to be green leaves spread out around the base and a 12" bright green stalk with light green bumps lining the underside of stems like little grapes.

When she touched the stalk there was a tiny cloud that drifted away.  The cloud of spores was released with each touch, as shown in this video.  We went back home to identify it.  What in the past would have been a nearly impossible task of thumbing through books became a one minute exercise with the photo above sent in to Inaturalist.

Wikipedia
This is a cutleaf grapefern, Sceptridium dissectum, a common fern, although easy to overlook when hiking as it is frequently found in overgrown disturbed areas.  It is a perennial but is easier to find this time of year because of its strange growing season. To grow it depends on a mycorrhizal fungus association in the soil.  Ferns are different from our common flowering plants and don't get as much respect, the Rodney Dangerfields of the plant world.  Stick with me as we muddle through this difference.

This grapefern produces a single frond (large, divided leaf) which spreads out at ground level, usually with lacy edges.  This often turns from green to a bronze color during the winter.  In fall, mature plants grow a single fertile section, which stands on a long stalk above the sterile part.  They are named for the round, clustered sporangium (spore cases) extending from the top of the stalk which have some resemblance to a bunch of grapes.  When we touched the stalk, the cloud you saw was the spores drifting away to the ground.

From here the fern life cycle gets very technical and hard to describe in simple terms.  Rather than confuse you further, I would suggest reading the best description I have found, here from UPenn.edu.

Resurrection fern during dry period
 Add water, no stirring required.
Another common fern species that can be overlooked is this resurrection fern, Pleopeltis polypodioides.   Gala Solari shared these photographs before and after a rain.  This is an epiphyte or air plant, meaning that it gets its nutrition and water from the air and the bark surface of a tree.  It is able to survive long dry periods and lose up to 97% of its water.  It does this by curling up its fronds, turning gray-brown and appearing dead.  Add rain and viola! it greens up.  It can survive drought for many years this way.  You can watch one revive in this time-lapse video.


From now on I will give a lot more respect to the ferns I encounter, even if I am still struggling to understand their strange life cycle.

You can read about the Christmas Fern in this month's Missouri Conservationist 
at this link.

Sunday, December 1, 2019

Insect-loving Fungi


During a recent WOLF School field trip at Bull Creek, one of the fifth graders turned over a rotting log and discovered the grisly crime scene above.  By carefully excavating it, he exposed the remains of a lepidoptera pupa case, its contents consumed by a parasitoid fungus.

These white powdery structures are the fruiting bodies of an entomopathogenic fungus, Cordyceps tenuipes. (Greek entomon=insect).  If one of its spores comes in contact with an unlucky moth or butterfly pupa or larva, it will germinate, penetrate the cuticle and then grow inside the host. This eventually leads to the death of the insect. Then the spore-bearing fruiting bodies emerge from the cadaver.  Remnants of the victim can be seen in this photo.

There are a great number and variety of entomopathogenic fungi. In fact, 5 of the 8 fungal phyla contain species which have evolved to feed on insects.  C. tenuipes and some other species have been studied for possible medical applications which are popular in China.

Cordyceps militaris in the soil - Mark Bower
Cordyceps militaris on a dead caterpillar - MB
A common Cordyceps species is C. militaris which Mark Bower shared with me.  Michael Kuo of Mushroomexpert.com describes it as "pretty much the coolest mushroom ever," but to identify it you need to dig a little deeper.  It parasitizes puffball mushrooms as well as insects, so simply plucking it from the ground leaves the underground origin a mystery.  In general it is always a good idea to dig down when collecting any mushroom because the substrate may help you identify it if only to know that it grows on wood.
 
Some species simply enter their host and devour it from the inside.  Incredibly, a few species can infect the creature’s brain and muscles and compel it to perform certain tasks.  For example, Ophiocordyceps unilateralis and C. lloydii fungi may direct an infected ant to climb a tree to a specific height so that the fungal spores will rain down on the unsuspecting ants below.  In an example of familiarity breeding contempt, Kuo states:
"Some ants and termites that have evolved the ability to detect Cordyceps-infected compadres; sentry soldiers guarding the Queen kill the infected insects and take their bodies far from the nest before they can threaten the colony."
Spider succumbed to Torrubiella arachnophila -MB
Now for a specialist in action we have Torrubiella arachnophila.  The species name arachnophila comes from arachno, "spider," and phílos, dear, beloved."  I suspect this is a case of unrequited "love," more likely an abusive relationship, as the fungus gets all the affection.   According to Mushroom Observer its "deprecated synonym" is Gibellula leiopus (Vuill. ex Maubl.) Mains, a debate we will leave to the taxonomists.
Beauveria bassiana on a wasp - MB
A final fungus that Mark photographed is "Beauveria bassiana," a species found around the world growing in the soil and parasitizing insects.  It is being used as a biological insecticide.  Studies showed it was highly effective in controlling bed bugs.  If you get the itch to try it you can find it at your nearest Amazon link.