Wednesday, July 8, 2020

Nextdoor Naturalist

I

We got this picture from our neighbor, Cyrus, who found who found these caterpillars crawling all over his false indigo bush, Amorpha fruticosa.  He had already identified them as silver-spotted skipper larvae, a species I hadn't seen before.  When they moved in next door two years ago, he plunged into nature immediately, replacing foundation plantings with native species and reporting lots of backyard insect finds.  He is helped by 3 year old Cobie who is curious and built close to the ground where she is eye level to many of their new plantings. Among other finds she spotted were these predatory stink bug eggs.



The silver-spotted skipper (Epargyreus clarus) is one of the largest skippers, readily identified from a distance by its distinctive white patch on the lower side of its folded wing.  Adults have a long "tongue" (proboscis) and feed on nectar from a variety of flowers as well as puddling on moisture and the odd dung droppings.

Early instar SSS caterpillar
As usual, the University of Florida has extensive information on the SSS. 
"Like most skippers, silver-spotted skipper larvae live in leaf shelters. First instar larvae make shelters on the apical halves of leaves by cutting a flap on the leaf margin, folding it over and attaching it with silk. Larger larvae often silk several leaves together to form shelters. During development, the larvae make four distinct types of shelters (Lind et al. 2001, Weiss et al. 2003). They leave the shelters only to feed or to make larger shelters."  entnemdept.ufl.edu

Leaf shelter

Cyrus located some leaf shelters and help me to photograph them as well as get a video of this rather annoyed caterpillar in its leaf nest.  Once we were through we taped the little branch onto the shrub so it could settle in for the night.

"Insect frass may provide chemical cues for parasitic wasps to the location of prey insects (Weiss 2006). Many caterpillars that live in leaf nests, including the silver-spotted skipper, forcibly eject their frass for considerable distances to eliminate these chemical cues. Silver-spotted skipper larvae utilize their anal comb to throw their frass a distance up to 38 body lengths (Weiss 2003)." entnemdept.ufl.edu

In spite of their best efforts, caterpillars end up at the bottom of a food chain.  Cyrus was able to get this phone video of a cardinal munching caterpillars outside his kitchen window.  The pictures above are of a few survivors that were missed.

Introducing a child to nature before they have learned to fear all insects is a great way to create a naturalist for life.  Cobie has learned to raise and release butterflies and find things in nature.  When I last saw her she was out in back "searching for cats."

Tuesday, July 7, 2020

Bees from Ben


From Ben Caruthers:

"Last year I had a tree in my yard that I would hear humming, eventually the sound went away. I heard it again this year, and thought I might just be crazy. Last night my wife finally heard it too. Today I decided to walk around it with my binoculars to see if I could see anything coming out of it. Attached is what I saw."

Click to enlarge
The mass of European honeybees are coating the tree trunk.  I sent the photograph to Avery Russell who confirmed that it was a swarm.  "They will likely spend a couple hours there before dispersing to find a good nest location. Though that's a very small swarm - if there aren't more hidden bees somewhere, it's a goner I think."

Ben tells me he is still hearing the humming when it is quiet in the morning or evening, just not nearly the volume that it was before. Now there is not a swarm of bees around the hole, just a few bees going in and out frequently.

Thomas Jefferson described their arrival in his 1785 book Notes on the State of Virginia.

"The honey-bee is not a native of our continent.  The Indians concur with us in the tradition that it was brought from Europe; but, when, and by whom, we know not. The bees have generally extended themselves into the country, a little in advance of the white settlers. The Indians therefore call them the white man's fly, and consider their approach as indicating the approach of the settlements of the whites."
We have a complicated relationship with these European bees. Obviously they are a big industry both in producing honey and in transporting them to agricultural fields for crop pollination.  Colony collapse disorder is a threat to these industries. 

On the other hand, honeybees can displace some native bee species, out competing them.  While effective in commercial pollination, in nature they tend to be less effective on many native plant species which have their specialist pollinators.  The honeybee is a generalist and therefore can pick up pollen from one plant and never visit a second one of that species, effectively wasting that pollen without fertilizing it.


In recent years there has been some cool discoveries about honeybee behavior which are described in Wikipedia.  They have colony defenses including fending off predators with the "Mexican Wave" and killing hornets by "balling" where they produce excess lethal heat and high carbon dioxide levels.

Photos by Ben Caruthers

Monday, July 6, 2020

Sawfly Ballet



This buggy ballet was filmed by Holly Welch who watched these dusky birch sawfly larvae feeding on her river birch leaves.  They are gregarious, feeding together as a family.  They tend to eat from the edge inward until they reach the petiole before moving on to another leaf.
















These sawfly larvae have a defensive startle reflex, designed to prevent predation.  You can see it in the photos above one second apart after Holly tapped the leaf.  Her video shows that this occurs in unison, increasing the startle of the predator.

Like lepidoptera larvae, sawflies have prolegs but theirs lack the little hooks called crochets that they use to cling onto the plant.  Prolegs don't have joints or flex like insect legs.  Instead movement is by extending the body and getting a new grip (think inchworm).  She reported that "I was looking at the larvae again this evening. It appears that the younger/smaller larvae feed from the underside of the leaves whereas the older/larger larvae feed only from the edges. Either way, not much is left of the leaves when they are finished."


Most sawfly species larvae are social, feed in large groups and strip a leaf clean.  They seldom harm the tree although they can be an unsightly pest in an urban setting.  Some species are a serious problem in horticulture.  They get their name from a saw-like ovipositor they use to put their eggs under the bark.  Like dragonflies and damselflies, their common name is one word rather than two (think house fly) letting you know that they aren't true flies in the Hemiptera family.

Dusky Birch Sawfly- Charley Eiseman CC
Sawflies are actually members of the wasp family.  Bug Lady describes the evolutionary path of the wasp family from laying eggs in wood, through species that make galls, paralyze prey with chemicals and finally the ovipositor becoming a stinger in what we commonly think of, and fear.  Sawflies lack a stinger and can't harm us.  The adults live for around a week and breed quickly without feeding.  For that reason they are not commonly seen.




Friday, July 3, 2020

Snapping Turtles


Bob Ranney sent this photograph of a snapping turtle that was 18" long, wondering
about its age. We sent this question to Dr. Day Ligon at Missouri State University.

"That is indeed a large snapper—especially for Missouri! Unfortunately, it’s not possible to infer age from size of adult turtles because, despite what you might hear, they don’t really exhibit continuous growth. These guys are omnivorous, and in many populations plants make up the majority of individuals’ diet. This species also typically reaches sexual maturity at 5-7 years, which is young for such a large
species. They lay just one clutch annually, but clutches can be huge, ranging from
30 to over 100 eggs. The eggs are spherical."

Omnivores indeed. according to MDC
Discover Nature
"Insects, crayfish, fish,
snails, earthworms, amphibians, snakes,
small mammals, and birds. However, up
to a third of the diet may consist of
aquatic vegetation. Carrion may also be
consumed." A few weeks ago there were
lots of frog eggs in two 15' water filled tire
tracks along the creek where I also found
a 10" snapping turtle. When I prodded it
out with a hiking stick it opened its jaws
to attack and out rolled hundreds of frog
eggs!

It has been a big year for snappers.  Besides the 10" snapper mentioned above, our stream ecology team found two others crossing the field.  At the other end of the size scale, our neighbor girls June and Kate found this little baby snapping turtle far away from the water.





MDC Discover Nature describes the young turtles as, "the upper shell has 3 rows of
low keels, but these are less apparent in older individuals." You can see this in the
one we found on the path at the Springfield Botanical Garden. It was motionless
and thinking it was dead I put it in my shirt pocket to take to the 5th grade WOLF
School. We left it on the kitchen counter over night (I married the right woman, a
saint) and the next morning we found it on the family room carpet 15 feet away,
crawling to freedom. We named him Lazarus and after its classroom duties it
returned to pond life.

There is a high infant mortality for eggs and young turtles as lot of nature has a taste
for them. Skunks, crows, foxes and raccoons are common predators of eggs and
young as are great blue herons, bullfrogs, hawks and snakes. The adults make up
for that high attrition by longevity. The snapper's life span in nature is uncertain but
one mark/recapture study documented a 100 year old specimen.

I was surprised at how far away from water we found them but this isn't uncommon.
They can travel a long way from water and females can hold sperm for several years
as necessary! Combining this with their ability to hibernate under ice for 6 months in
northern climes and we have one tough mama!

My first encounter with a snapper was in 1997, long
before I had any nature education. We found this one
crossing the field headed toward the creek. I had
been told that they could "wipe out a fish population"
and foolishly we shot it. We then turned the carapace
into a wall light sconce and are continuously reminded
of how important getting the right information about
wildlife can be for humans and other animals.

Another important lesson is picking up a snapper by
the tail can cause serious internal damage to the
turtle. Picking it up by the shell may provide a painful
lesson on how far it can extend its neck. Knowing
what I know now, I now would limit my contacts to a
camera like this one back in 2013.

More details at Wikipedia.

Tuesday, June 30, 2020

Leaf Miners


Leaf miner on Verbesina virginica - REK


We have all probably seen these discolorations on a leaf.  At that point we have either walked on or said knowledgeably "leaf miner," and then walked on.  Below is a great way to learn more about them from the expert, Charley Eiseman.

I first came across Charley when I became interested in plant galls and discovered his bible of natural signs in nature, Tracks & Signs of Insects and Other Invertebrates.*  It is full of interesting finds that continue to make me focus on the macro world.  If this sounds like a commercial, I plead guilty.

I run into his work everywhere, whether responding to a finding on INaturalist or contributing 10,892 photographs on Bugguide, all for free use through Creative Commons.  He is a member of  a community of fellow "macrophiles" and amateur and professional entomologists out there who are willing to give us junior members help as needed.

Leaf miner tunnels with trails of frass - REK

Red Velvet mite
While photographing a velvet mite,  I saw these scars on top of a frostweed leaf.  I had always assumed that they were caused by something browsing the epithelium but it turns out to be something much more interesting. They are made by tiny larva living between the upper and lower leaf epidermis, tunneling and pooping a faint trail of dark frass.  Depending on the species, they may occur on the upper or lower surface, sometimes on both.  Eventually they emerge, leaving through a small exit hole which you may see under magnification.

 

A leaf miner is any one of numerous species of insects in which the larval stage lives in, and eats, the leaf tissue of plants. The vast majority of leaf-mining insects are moths (Lepidoptera), sawflies (Symphyta, close relatives of wasps), and flies (Diptera), though some beetles also exhibit this behavior.  Wikipedia


Lately Charley has plunged into the world of leaf miners.  There are over 2,000 species of leafminers and since most are plant specific you have a good chance to identify them by their tracks.  If you want to pursue leaf miners beyond the Wikipedia reference, Charley has just published Leafminers of North America.  It is 1857 pages long (plus a 54-page table of contents, 20-page glossary, and 68-page bibliography), illustrated with thousands of color photographs.  To prevent injury to the UPS delivery drivers it is only available as an ebook but it is a great reference.  "Abandon all hope, ye who enter here" for I have sampled the incredible deep dive into my copy and it is hard to emerge.

Now he has done it again.  He has a 78 minute webinar, an introduction to leafminers at this Youtube link.  If you find it as interesting as I did, you might consider signing up for a series of webinars through August where he will be walking us through the identification of leaf miners, no hard hat required.

=================
From Charley Eiseman
"If you're interested in an interactive webinar that will help you become more comfortable using the book's keys, you can register for that here:
https://www.eaglehill.us/programs/sems-online/calendar-online.shtml
The course flyer will be available at the above link any day now, but for now I've copied and pasted the description below.
The first session will include a slide show/lecture providing an introduction to leaf and stem mining and other modes of herbivory; an overview of mine classification; and a discussion of methods for photographing, collecting, and rearing miners. In between classes, participants will photograph and/or collect leaf and stem mines and attempt to identify them using the hostplant-based keys in Leafminers of North America.  At each subsequent meeting, we will discuss what people have found, working through the keys together for any mines that have caused difficulty.  This will ideally be done by sharing digital photographs taken ahead of time, but for some specimens live sharing via webcam may be possible.  Shortly after each meeting, the instructor will provide a list of relevant passages in Leafminers of North America to read that will reinforce what we have covered together.

=====================

*He and Noah Charney wrote Tracks & Signs of Insects and Other Invertebrates which is an indispensable book for those who wander through nature wondering "what made that?" be it a gall, egg case, pupae, exuviae or an engraving left by an insect. 

Monday, June 29, 2020

Larry the Leech

Our great niece Taylor's friend, Luke found this leech in a puddle near the swimming hole.  Taylor said she recognized it from last year when it had a close relationship with her toe, then they named it Larry.  We explained that once you name an animal it achieves pet status and can't be killed or used for bait. I identified it as a Placobdella sp.  We renamed it "Della" and after the swimmers left it went back into the creek.

Ventral surface with stripes

Posterior sucker
The best match I found on INaturalist was a smooth turtle leech, Placobdella parasitica.  Wikipedia states that "P. parasitica is differentiated from other members of the genus Placobdella by its smooth dorsal surface, simple to complicated pigmentation, and abdomen with 8 to 12 stripes."  Positive identification requires dissection which Taylor was more than willing to do as payback.  Since some leeches can live up to 10 years she was certain this one had sucked her blood several times in the past.

Leeches are parasitic or predatory worms, distant relatives of our earth worms.  Most leeches are blood sucking parasites without a specific host species. They inject their saliva which contains anesthetic and anticoagulant chemicals, making their bite with serrated jaws painless.  Once they have had their blood meal they drop off and may not feed again for many months.



The MDC Field Guide is a good resource to start with.  A leech has a sucker on each end of its underside and can use them to move like an inch worm, stretching and expanding dramatically.  The head with the mouth is actually located at the small tapered end.  The power of its sucker can be seen here when I picked it up by the head end and it was able to lift a rock with its tail sucker!


Leeches have a long medical history dating back 3,500 years.  Even the word “leech” is derived from the English word “laece,” meaning physician. (Ouch!)  They were used for bleeding as treatment for a wide variety of diseases, and are still used in digital transplant and skin flap surgery to treat venous congestion.  Sciencedirect

Removing a leech should be done gently, trying to peel it off with a fingernail to avoid leaving mouth parts in the skin.  Salt, alcohol, turpentine or vinegar will cause it to detach but makes it vomit in the wound. (TMI)

Finally, some people are keeping leeches as pets.  Even though they are easy to raise and you only have to feed them every 3-6 months, Barb said "NO!"

Saturday, June 27, 2020

Chub Mound


Our stream ecology research team took to the water for an afternoon snorkel trip down 2 miles of Bull Creek.  One cool find was these under water gravel edifices created by a male chub.  The species I have seen and caught in our swimming hole is the hornyhead chub (HHC)  Our common Missouri chubs are 5 to 7" long members of the minnow family.
Horneyhead Chub on Bull Creek - Dave Fleshman

Like males of some other species including us, when looking for love the HHC gets dressed up to attract a lady chub.  In this case he develops large pointed tubercles on the top of the head and a red or orange spot on the upper opercle behind the eyes.

HHC - Dave Fleshman
Like bower birds and other love-struck males that build a love nest to attract a female, the river chub creates a mound nest of gravel for mating.  He does it one piece at a time, first picking up pebbles in his mouth and moving them to the side, creating a shallow pit with a rock rim.  Next he picks up uniform 1cm pebbles from up and down stream, creating a mound.  This can have up to 10,000 pebbles!  Talk about chapped lips!



The mound will have a trough on top and when she enters it he will hold her down as she releases some of her 500-1000 ova.  From then on, the male will fiercely guard the nest, head butting intruders.

Ovisac with several hundred glochidia *


Chubs are an indicator of high quality water and are intolerant of pollution.  They are a valuable member of stream species and food for other fish.  Their diet includes insects, filamentous algae and even the eggs of mussels. 



"Fresh-water mussels release small masses of microscopic larvae known as glochidia in a loose gelatinous matrix or ovisac. The glochidia encyst on the gills of river chubs where they metamorphose into juveniles and then drop off. It is suspected that the river chub feeds on the gelatinous masses as it does drifting insects." Wikipedia

* Barnhart, M. C.  2008. Unio Gallery:  http://unionid.missouristate.edu.