Wednesday, July 31, 2013

Red-backed Jumping Spider



The picture on Friday's blog is a facial view of a spider showing two big eyes like headlights, two smaller eyes to the side (turn indicators?) and four small eyes across the top.  Taken with my pocket Lumix, the picture lacks the clarity of the big league photographers but I suspect some of you recognized it as a spider.  The blue-green structures are the chelicerae, hollow mouth parts which connect the venom glands to the fangs at the tips.

Kevin Firth emailed within 4 hours with an ID as a jumping spider of the genus Phidippus.  I was amazed because spiders are tough except some of the more distinctive species.  I have contacted a lot of entomologists over the last few years, and even they sometimes ask if I know a "good spider expert."

Some species can be narrowed down by their web construction, habitat and body shape.  My specimen jumps dramatically, which is how I spotted it in Brian Edmond's dense prairie plantings. The final ID as red-backed jumping spider, Phidippus clarus, was made from browsing through jumping spiders in Bugguide, and comparing each with my full body photograph.


There is a lot of information on P. clarus on the web, particularly on Wikipedia.  Some of it is highly technical but there is also a lot of gee-whiz facts.
  • Those big eyes really work.  Their vision exceeds that of a cat and is 10 times greater than the dragonfly which is the most acute of all the insects.
  • Their powerful back two sets of legs allow them to jump 50 times their length, the equivalent of my jumping 250 feet.
  • "In an experiment, P. clarus was offered as many fruit flies as it could eat, and in four-hour sessions individuals took 17 flies on average – while one took 41."
  • Males compete for the largest females which then produce the largest number of offspring.  "When P. clarus males compete for females, the winners are those that produce the most vibrations on the surface and those that are largest. Contests between females involve less displaying, and physical fights between females are more likely to end in injury or death. " Mating rituals are complex and the average female produces 135 eggs in her sac.
  • They hunt by sitting at the top of vegetation and pouncing down on their unsuspecting prey.  They, or their egg sacs, are placed sometimes in agricultural settings to feed on plant pests.
All spiders have silk glands which we associate with webs but some have adapted them to other uses.  The jumping spiders make silk shelters for protection of their eggs and a safer place to hang out while they are molting.

You can see a video of male and female P. clarus on this rkwalton.com link.  Arachnophobes beware.
An extensive collection of jumping spider videos can be found at this Dick Walton Natural History Services link.

Monday, July 29, 2013

Eight-spotted Forester Caterpillars



Roy Thompson sent us these pictures of caterpillars.  Here he shows what a walk in the woods by a sharp-eyed and curious naturalist with a modern phone camera can accomplish. 

He is one of several of our Butterfly House friends who can't pass a chewed leaf without pausing to see what's eating it.  In this case he was working when he saw a tree draped with grapevine and inspected the leaves.  He found several eight-spotted forester moth caterpillars, Alypia octomaculata,  of varying ages and used his I-phone to get their pictures.  After that he carefully collected the caterpillars and the grapevine leaves to raise them in a safer predator-free environment.

Early instar out for lunch
After emerging from their tiny eggs, these caterpillars likely chew up the remains of their former home before eating through the nearest leaf.  From this time on they will be non-stop eating machines.  Most lepidoptera (butterflies and moths) caterpillars require specific food plants to survive and grow.  In the case of these foresters, they need grapevine or Virginia creeper.  They eat everything tender enough to chew including small tendrils, leaving only the heaviest veins and leaf petioles.

They will be going through five ever larger caterpillar stages, called instars.  An early instar is seen to the right crawling up the petiole of a leaf.  They eat constantly, pausing only to avoid bad weather and to occasionally slip into something more comfortable.

More accurately, they slip out of something uncomfortable, skins now too tight to hold their expanding bodies.  This shedding or molting starts by attaching the rear of their abdomen to a structure, then unzipping the skin on the back of the head before crawling out of the old skin like we crawl out of a sleeping bag.  The new skin has room to expand, containing its host until it is ready to progress to the next instar stage.

Fourth instar- Click to enlarge
Like many other caterpillars, each instar looks a little different in color or pattern.  Some types of caterpillars change color and shape so dramatically that you would never even guess that they are the same species.  In this case the last instars look similar although larger.  Soon the last instar, seen at the top, will form a pupa, the last step before the final reincarnation-like act of emerging as a beautiful moth.

Life is hard if you are a juicy colorful caterpillar perched on a leaf.  Grape growers consider them a pest and may spray them.  These cats defend themselves from predators by vomiting a clear orange fluid.  They also will drop off the leaf and are spared a rough landing by a bungee-like cord of silk.  Roy's cats are living in a more protected environment so you and I will have to wait a while for the next installment in their story.

Friday, July 26, 2013

Missouri Oaks in Minnesota

Mighty Missouri oaks growing in Minnesota- Matt Kaproth
Missouri oaks are growing in a lab in Minnesota in a study of Relative Growth Rate and drought tolerance between species.  We described the collection process in last fall's blog so I won't repeat all the science behind it here, but will quote from that blog to explain the why of the study.
"We can look into which oak species withstand stresses better than others. With the recent droughts (and more predicted to come), we can identify which lineages have drought-tolerance, which can pass on this trait, and which species stand a better chance to survive with changing climates. You can’t get anything for free in nature though, and it’s hypothesized that lineages that can handle water stress have slower growth rates. Identifying this trade-off will let researchers predict species range limits and guide managers about how to care for their oaks."
The research is headed by our friend Dr Matt Kaproth.  Matt is a PhD in botany.  In the description by the child of a friend with a PhD, "Dad is a doctor, but not the kind that helps people."  He sent me some pictures of his research as well as more information on the process.

Forest under development- Matt Kaproth
In Matt's own words:
"I ended up planting over 5,000 acorns of 41 species. They've been growing on the Saint Paul campus of UMN for 5 months and I have currently transplanted 1000 plants.  I'm setting up irrigation supplies to start changing the watering treatments for the big plants soon - watering to saturation every other day, every other week and monthly. We'll see which species can handle drought and which fizzle out. We think there is a tradeoff between Relative Growth Rate (RGR) and drought tolerance, meaning that a plant that can handle drought has a lower RGR, thus there's a cost to being able to withstand drought - you put on less weight than ones that can not (but you stay alive)."
While the methodology of measuring the RGR is complex, the concept is understandable to us simple naturalists.  The RGR quantifies the speed of plant growth.  It is the mass increase per above ground biomass per day.  Over time as the plant grows, the RGR usually decreases as the plant biomass increases.  This is probably because as the biomass (roots and stems) increase, the top leaves start to shade the lower leaves, limiting photosynthesis while the plant's respiration (yes they "breathe") continues at a rate proportional to the biomass.  Also, with time, the soil nutrients can start to be depleted.

Matt's study may eventually contribute to our knowledge of which trees are best to survive our changing climate and still grow larger to help suck the increasing CO2 from our atmosphere.   Maybe he is the kind of doctor that helps people after all.




Coming soon to the blog.  
What is it?


Wednesday, July 24, 2013

Wavy-lined Emerald

Camouflaged looper with flower petals attached-  Charley Eiseman
Kevin Firth got me started looking at the wavy-lined emerald moth with this note. 
"The larvae are flower feeders that camouflage themselves with bits of whatever plant they are feeding on.  We had a bunch of them about five years ago around the house.  I found them on Prairie Blazing Star."
The wavy-lined emerald,  Synchlora aerata, is a fascinating critter.  Its caterpillar is commonly referred to as a camouflaged looper.  Unlike the camo of natural coloration, this caterpillar will attach plant fragments, especially flower petals to its back as it feeds, nature's version of a ghillie suit.  It is the only wide spread species that applies this artistic camouflage.

Synchlora cat- Steve Kortum
Sticky cat - Synchlora aerata Marvin Smith












The results can be quite striking and variable like those above, to the degree that you would never guess that these were the same species.  Part of the reason for the colorful variation is that they feed on a wide variety of plants including many flower heads and petals as well as trees and shrubs.  They seem to prefer composite flowers, especially (Asteraceae), including Aster, Rudbeckia, Liatris, Solidago, and Artemisia.  This gives them a wide variety of colors to chose from.  Since the fragments are always fresh looking they are probably replaced daily.
Dressed up for dinner- Kevin Firth

Find the looper caterpillar- Marie L. Schmidt
 Wavy-lined emerald - Synchlora aerata Tom Murray

The adult moth is a pale green with faint wavy lines running along the wings and a dainty fringe on the hind edges.  They are found widely over North America.

More caterpillars are seen on this Bugguide link

Click on this video showing attached flower petals shaking.

Monday, July 22, 2013

Abandoned Turkeys Get New “Mom”

From Jennifer Ailor
 
John Holt, who lives south of Allan Keller and me on Highway W southeast of Ozark, discovered a nest of turkey eggs hidden in the tall grass he was brush hogging in early July.  They were fresh so he carefully transferred the seven eggs to his brooder house where in short order they hatched.

Now about a week old, the babies are already are losing their fuzz. As he begins to let them out during the day, John expects to see them flying at two weeks and soon roosting in trees. Before you know it, he says, the young ones will attract mature turkeys and return to the wild with those birds. Based on others’ experiences, he doesn’t anticipate imprinting problems.

Most baby turkeys don’t make it to adulthood or even close. As poults, in their first three weeks of life, they are tasty eating for just about every predator, plus are sensitive to cold and wet. The mother hen is their only protection. Without that mother, these young turkeys are fortunate indeed to have been given a chance at life.

Editor's note:
What to do with abandoned baby animals is always a tough call. We know that if a baby bird is found away from the nest it is best to leave it for the mother bird to deal with. What about turkeys? If you find a turkey nest it should be left alone, giving the mother a chance to continue to brood the chicks. However, in this case the nest was close to a house, the tall grass cover had been mowed down, exposing the nest, and there are dogs, coyote, fox and bobcats around. I believe this Illinois Extension article confirms John's wisdom.
"Wild turkeys lay an average of 10 to 12 eggs, approximately one egg a day until the hen has a full clutch. Incubation is done by the hen only and lasts for about 28 days. Hens are very sensitive to disturbance while nesting, and are likely to abandon their eggs if they are startled from the nest. Young turkeys are called poults and are cared for by the female only. Poults are ready to leave the nest within 24 hours of hatching." 
Poults eat primarily insects during their early growth phase when they need lots of protein. They are particularly vulnerable in the first 10 days before they can fly to roost in the trees. Until then, John has his hands full.

Friday, July 19, 2013

One-eyed Abbott


I stumbled across this picture in my files yesterday, an unknown from 2010 that I had never identified.  Its dramatic single eyespot on the top of the head was distinctive but I couldn't find a match so I sent it off to Kevin Firth's same-day service.  Bingo!... Abbott's sphinx moth caterpillar.

The caterpillar of Abbott's sphinx, Sphecodina abbottii, changes its appearance dramatically  during its four instars (molts).  As you can see from the pictures below by Jo Ann Poe-McGavin, the first instar starts with a horn resembling a hypodermic needle.  The second instar loses the horn, converting it to an orange spot.

First instar- note horn

Later instar- horn replaced with orange knob


With the final instar before it forms its cocoon, things get really interesting.  The orange spot becomes a very convincing eyespot, complete with iris, pupil, and even the white reflecting spot in the middle.  To complicate things further, it can either be a brown color with 10 pairs of pale green saddles or come out in a tan wood-grain pattern like ours above.  If poked, it is said to squeak and bite at the attacker.
My wood grain version
Last instar, green version- Eddie Calloway









Abbott's sphinx moth- CircusCyaneus
The moth that emerges from the cocoon is no slouch either.  Its scalloped wings and coloration blend right in with tree bark and it adds to the effect by raising its abdomen at rest, resembling a broken twig.


Thanks to Jo Ann Poe-McGavin who makes all her pictures available for our common use.  She has submitted more than 3,000 pictures to Bugguide. 

Wednesday, July 17, 2013

Rattlesnake Sunday

Pigmy rattlesnake in the grip of the grabber
For reasons I can't explain, the rattlesnakes around the Bull Creek house seem to show up on a Sunday.  I was at my garage workbench last Sunday and saw an 18 inch pigmy rattlesnake laying quite still.  When I poked it with a stick, it attempted to escape, I trapped it with a stool and caught it with my snake grabber.  I took comfort in the fact that it wasn't a small timber rattlesnake as I keep telling myself they aren't in the garage.


Resting in the long pillow case
I transferred it into a long pillowcase we keep with the grabber and after a portrait session, took it up the creek a half mile to release it along a bluff. I took it out with the grabber and it expressed its gratitude by displaying its wide open jaw, an impressive two inches, and sinking its fangs into the rubber disks of the grabber. Note to self- get a longer grabber.

Biting the grabber
The western pygmy rattlesnake, Sistrurus miliarius streckeri, is the smallest Missouri rattlesnake, averaging 15-20 inches.  Its tiny rattle can only be seen and heard by being closer than you want to be.  The buzz is said to be like a grasshopper.  They have a red-orange stripe down the back and incomplete black bands across the back.  On first glance they resemble a small timber rattlesnake, but the timber has black bands that extend along its sides.

Pigmy Rattlesnake- MDC
Timber Rattlesnake- wikispaces.com

Pigmy rattlesnakes live on lizards, snakes, frogs and mice, the latter being abundant in our garage which probably was a major draw to this specimen.  Young rattlesnakes have a colorful tail that they will wave as bait to lure toads and frogs into striking distance, a technique called "caudal luring."  Adults tend to sit and wait for prey to pass by.

They live under rocks on cedar glades and are said to be "so secretive that few people encounter italthough we have at least one come down from our overgrown cedar glade almost yearly.  They are found in southern Missouri and on through the south central US.  Another name for them is "ground rattler" - in opposition to what, an aerial rattler?  That is one I don't want to see.

 Herps of Arkansas has a lot more information on them.

Monday, July 15, 2013

June Beetle Grub


Barb spotted a big fat grub in our lawn at home and laid it on the patio table and said, "You have got to see this!"  As I watched, it twisted around from its C-shaped posture, rolled on its back and started crawling with its legs in the air.  I spent the next few minutes turning it over to get it to repeat the performance, a feat that it never tired of.  Check out it doing a backstroke on this video.

With the help of Google, I discovered that only the green June beetle, Cotinis nitida, and the bumble flower beetles, Euphoria, travel this way, and the June beetles are far more common.  Their legs are short and considered inadequate for travel but they wiggle them in the air as they go, as though that would help.  They have short stiff hairs on ridges of their backs which help them gain traction on the grass.

The third and final instar overwinters eight inches below the surface.  In the spring it burrows up closer to the surface, then moves through the soil on its back, feasting on decaying matter before forming a pupa.  It uses sticky secretions to hold soil particles together, forming a protective case from which the adult beetle will emerge in 16-18 days.

Green June Beetle- Wikimedia
The adults meet on your lawn, mate, then the female lays her eggs three inches deep in rich organic soil.  They might have to hunt for a home in nature, but they thrive where humans provide nurseries such as fertile lawns and gardens.  The eggs are buried in clusters of 10-30, wrapped up in a clump of dirt.

The grubs that emerge feed on decaying matter.  They are considered a serious pest on tobacco plants as they crawl through the soil, loosening and uprooting the plants.  They should be the symbol of the American Cancer Society campaign against smoking, but instead they are considered pests because of the damage they can do to lawns.

The large blue-winged wasp, Scolia dubia, is commonly seen flying low over grub infested lawns.  The female wasp actually digs into the soil to find green June beetle and Japanese beetle larvae.  She then stings a larva into paralysis and lays her eggs.  When they hatch, her larvae will consume the grub.  Even Japanese beetles have some benefit. 

To identify white grubs, go to this guide.

Friday, July 12, 2013

Snakes feeding at night

After lunch nap at Rattlesnake Bend
It is no longer news that we are in a period of warmer temperatures.  This is good news for for our cold blooded snakes but bad news for some baby birds.  First the good news for snakes.
Speckled kingsnake at Rattlesnake Bend
Snakes are ectotherms, which we think of as being cold blooded.  This really means that they lack the ability to control their own body temperature like mammals.  Instead they seek out places that are within their comfort zone like I head for the swimming hole or crank up the A/C on hot days.  We have a shaded curve in our gravel drive that we call Rattlesnake Bend because we frequently see rattlers as well as a ratsnake or speckled kingsnake laying on the road that was warmed by the early morning sun while escaping the direct sun rays.

Ratsnakes are the number one predator of nesting birds, quite capable of climbing up trees and bluebird poles.  Some people are surprised that snakes can climb, as was our neighbor who found a copperhead at eye level in her tree.  Our resident black rat snake easily climbs up the flat side of our house to its second story entrance as it has demonstrated to us several times.

University of Illinois researcher Patrick Weatherhead described the normal pattern of a hunting ratsnake in this 2010 article. The ratsnake normally hunts in the forest, then heads to the edges and openings to warm up.  With the warming climate of recent years they are hunting more at night and seeking shade in the day.

Rat Snake- Shelly Cox
Weatherhead's 2013 research is described in this sciencedaily.com article.  He and his colleagues are studying ratsnakes and their response to the warming climate in Canada, Illinois and Texas.  They are finding that nocturnal hunting is still on the increase.  This is bad news for birds.
"Females are often on the nest incubating eggs or brooding the young at night," Weatherhead said. "If they are doing that during the day and a snake approaches, they rarely get caught by the snake, but at night they are much more vulnerable because snakes are very stealthy and the incubating birds don't detect the snake approaching. This is good for the snake because it gets a bigger meal."
"The environmental repercussions could be significant if you start eliminating adult females from a population, particularly an endangered species," he said. "The loss of females for native birds will have a big demographic effect on bird populations."
This has implications for humans as well.  University of Missouri biologist John Faaborg studies snake populations and birds such as the Acadian flycatchers and indigo buntings whose numbers are down in warmer years.  They bred in the forests before spreading out to other territories.  They help control mosquitoes which can carry West Nile virus.  In Sciencedaily he describes these implications of changing snake behavior.
"Low survival in the Ozark nests harms bird numbers in other areas," Faaborg said. "Birds hatched in the Ozark forest spread out to colonize the rest of the state and surrounding region. Small fragments of forests in the rest of the state do not support successful bird reproduction, so bird populations in the entire state depend on the Ozarks."
Researchers expect that the warming climate may expand the range and numbers of snakes in the northern states.  The black rat snake's scientific name is Pantherophis obsoletus, the obsoletus being Latin for old, worn out, thrown off.  This might as well refer to it common name of Texas ratsnake, more recently renamed the Western ratsnake.  With the warming climate it may eventually be renamed the Ontario ratsnake.

Wednesday, July 10, 2013

Birds of a feather


Looking out on the deck yesterday morning I saw a little gray lump that hadn't been there a few minutes before.  In spite of the grumpy look on its face, it just sat there unconcerned with my presence as I took its first baby pictures.  I could hear a scolding bird calling incessantly in the tree above but could never get a look at it.
"Get out of my face!"

I retreated inside and when I looked out ten minutes later it was gone.  I assume that it had made its maiden voyage from the nest and was resting up for another try.  Since many baby birds look the same at that age, I guess I will never know what species it was. 

A short video from the Missouri Department of Conservation is filled with "Awww, how cute!" moments as it explains the different habitats that birds raise their chicks in.  Many birds nest in isolation, selecting territory where there is less competition.  Black vultures manage to raise chicks on a bare ground floor of our barn.  The bluebird boxes are now hosting second broods and a wren has taken over a hanging flower box just off our deck.

Purple martins have one of the more unique methods of nesting.  They are communal cavity nesters, formerly selecting dead trees with multiple woodpecker cavities.  When the first settlers came along, they harvested dead standing trees preferentially, a rapid source of dry firewood for heating and cooking.  Fortunately, the martins were becoming adapted to and adopted by humans.  Soon they became dependent on us and today they only nest in human supplied housing.*

Purple martin chicks
There are now nesting purple martins in their special house above the lake at Close Memorial Gardens.  Since the houses are tended to by Charley Burwick, cleaning out nesting attempts by other birds, we have a chance to see the young chicks.  If you stroll the lake with your cell phone you can hear more about purple martins, or you can read the script here, as written by Katie Steinoff and Charley Burwick.  The Butterfly Festival on July 20th will be a good time for a visit.

Today's News-Leader article describes how Native American's started adopting purple martins by hanging hollowed gourds in their villages before the arrival of European settlers.  They may have functioned as scarecrows as well as a natural form of a "bug zapper".  Either way, the purple martins became comfortable with humans, a fact that helped them survive in communal nests as the forests started to be depleted.

Mounted specimen- Wikimedia
Another communal cavity nesting species did not adapt to humans, nor we to it, and it rapidly became extinct.  The Carolina parakeet, North America's only native parrot disappeared by 1920.  It had covered the forests in large loud and colorful flocks of up to 400 birds.

Their habit of flocking together may have protected them from most predators.  They were probably poisonous from eating toxic cockleburs (Xanthium strumarium) as Audubon noted that cats apparently died from eating the birds. Feasting together on the fruits of the forest and returning to their nests together, life was good.  Then a wave of humans crossed the landscape.
"Outside of the breeding season the parakeet formed large, noisy flocks that fed on cultivated fruit, tore apart apples to get at the seeds, and ate corn and other grain crops. It was therefore considered a serious agricultural pest and was slaughtered in huge numbers by wrathful farmers. This killing, combined with forest destruction throughout the bird's range, and hunting for its bright feathers to be used in the millinery trade, caused the Carolina Parakeet to begin declining in the 1800s. The bird was rarely reported outside Florida after 1860, and was considered extinct by the 1920s."  allaboutbirds.com
Multiple factors led to the extinction of Carolina parakeets, but many feel that the habitat loss of standing dead trees with hollow nesting sites was a major factor.  In addition to the harvest of timber, they faced competition from the advancing wave of European honeybees which accompanied and even preceded the settlers.

Carolina parakeet flocks were extremely noisy, making it unlikely that anyone would have wanted to provide nearby nesting habitat.  Like our Monarch butterflies, being poisonous wasn't enough protection from the environmental changes brought about by humans.  Whether we know it or not, we pick the winners and losers.

So what are we losing when a species disappears.  Francis Skalicky of MDC shared with me this 1877 account by Gert Goebel, a German immigrant to Franklin County***
"Until the later thirties (1830s) great flocks of paroquets came into our region every fall and frequently remained till the following spring.  They were a small variety, about the size of a dove.  They were bright green in color, and their heads were orange colored.  These flocks of paroquets were a real ornament to the trees stripped of their foliage in the winter.  The sight was particularly attractive, when such a flock of several hundred had settled on a big sycamore, when the bright green color of the birds was in such marked contrast with the white bark of the trees, and when the sun shone brightly upon these inhavited tree tops the many yellow heads looked like so many candles.
This sight always reminded me vividly of a kind of Christmas tree which was used by the poorer families in my native Germany."
Our threatened regal fritillary and swamp metalmark butterflies may not be a noticeable as the "paroquets" but some of us would miss them if they were gone.

*    The full purple martin story is at purplemartin.org
**  More extensive information on Carolina parakeets is on Wikipedia.
***  The Carolina Parakeet of Pioneer Missouri

Saturday, July 6, 2013

Tick Watching

Tick removal- lawestvector.org
The News-Leader just ran a story titled Mild Winter Triggers Bumper Crop of Ticks, Other Crawlies.   In addition to information on tick avoidance and removal, it supplied some interesting statistics on tick-borne diseases.

The News-Leader table above may be a little misleading.  I suspect that 2013 will be a big year for diseases.  Notice that the 2013 data are those reported "through May 31".  Many people who went to the doctor in the last 2 weeks of May would not have had their tests back and reported by then and this doesn't get into the June through August period.  It may be a long summer.

You know you have been in the outdoors too long when you start to identify the species of every tick you find crawling on you.  We have reached that point.  Female lonestar ticks predominated through the spring but we are now starting to see a significant percentage of female dog ticks.

If you are interested in developing this thrilling new tick identification hobby, or are just curious about what is crawling on you today, I would recommend printing off this Tick Identification Chart PDF from the Virginia Department of Health.  It has good pictures of all three stages of the Blacklegged, Lone Star and American Dog ticks.  It also has concise information on the disease transmission vectors and times.

We haven't yet started to keep a spreadsheet with the tick ID, time and date like dedicated bird watchers.  That would really be sick, but it may be the next big thing.

Wednesday, July 3, 2013

Missouri the Beautiful


Sometimes I forget what rich diversity we have in the Ozarks.  We are blessed with a mixing of prairie, glades, forests, fens and wetlands, intersecting in the middle of the state, with rich rivers draining to the east and south.

The Fourth of July seems like a good time to celebrate our Missouri heritage and this MDC Video sums it up beautifully.  Have a happy and safe Fourth, and get outside.

Tuesday, July 2, 2013

Caterpillar Migration

Moves straight- not a snake
Nancy Schanda sent me this video of a migration across her walking path in Forsyth, high above Lake Taneycomo.  There were several of these slow moving, snake-like columns which almost have a wave like appearance on close viewing.  Her accompanying pictures show it was made up of a mass of tiny caterpillars piled deep on one another.  This phenomenon was new to both of us.

The Eastern tent caterpillars and forest tent caterpillars will move in mass from one tree to another, but I hadn't seen pictures showing them bunched together in an organized fashion.   

Pine processionary caterpillars travel in a line, nose to tail, as seen in this video.  They are also a tent caterpillar.  They come equipped with irritating hairs that can stick in your skin like a tiny harpoon.  They remind me of a Roman Legion Army with its spears sticking out in all directions, staying in line with such determination that they can actually go on a march for days.
"Fabre conducted a famous study on the processionary pine larvae where a group of them were attached nose-to-tail in a circle with food just outside the circle; they continued marching in the circle for a week. The caterpillars may follow a trail of pheromones or silk, but the main stimuli that induce following are from the hairs (setae) on the end of the abdomen of the caterpillar in front. The ant mill is a similar phenomenon."
These however are in one mass, seeming to crawl all over each other in an organized fashion.  Feeling lazy, I sent this off to Kevin Firth and Tom Riley and got my answer back within the day.  Proving again it is not just what you know but who you know.

Larvae- Tom Murray
Kevin sent the Bugguide link to Unidentified Sciarid Larvae and Pupae, the massed larvae of tiny flies called fungus gnats.   The link shows identical pictures of grubs in mass migration.  The individual larvae are not that impressive and very hard to make out in the herd.  The migrations tend to occur in moist weather, frequently in early morning when they can escape the dessication of the sun's rays.


Fungus gnat- by Richard Leung
Bugguide.com describes fungus gnats as "flies are black or brownish, 3mm in length or less and have short antennae.  The veins near the costal margin of the wing (C, R1, and Rs) are heavy, while the remaining veins are quite weak. ... The larvae breed in decaying material and excrement. The group is a small one (61 North American species) but its members are sometimes abundant"  They are said to sometimes eat root hairs of plants and can become a pest in mushroom growing operations.

Tom shared a link to a blog of the Delaware Nature Society demonstrating a continuous circle when the head of the column accidentally merges with the end.  For some reason, this reminds me of my days in the Army.