Monday, August 21, 2017

Raising Imperial Moths


We have had a number of Imperial Moths come to our deck light the last few weeks.  As usual, most of these are males with their big feathery antennae sniffing for wafting female pheromones.  We did manage to find 3 females and as expected, they immediately started laying eggs in the paper bags that became their new homes.  Mary Bennett also found some eggs and all told we are raising over 240 eggs.

Imperial eggs with ballpoint pen - REK
The Imperial Moth, Eacles imperialis is one of our beautiful giant silk moths.  The thought of putting a newly fertile female in a paper bag for a few days may sound cruel, but since her role is to reproduce, I think we are doing her a favor.  In nature, her larvae must emerge and take their chances with predators that are looking for them and a variety of parasitoids can lay their eggs on the caterpillars.  We are protecting her brood and feeding them.

Imperial eggs day 15 - REK
Adult silk moths lack a digestive tract and don't eat.  Having mated, the female searches out a spot to lay eggs where the larvae will be able to find food.  She lives only long enough to meet her biological imperative.  The eggs are glued to a leaf  where they develop over two weeks.  Then they turn from clear to yellow, beginning to show the caterpillar curled up inside.*  They start to chew the inside of the eggs slowly, obtaining nutrition and eventually their freedom.  The first instar will soon emerge and start to wander around, frequently with the empty egg chorion shell still attached.


Riding a petiole - REK

The caterpillars feed on a variety of conifer and deciduous trees.  Our caterpillars have been munching leaves of maple, sassafras and sweet gum.  We are raising them in plastic containers with tissue or coffee filters on the bottom for convenient emptying of their frass.  They are not naturally gregarious but don't seem to mind the company.  That is a good thing as with 180 eggs to go, we can't provide individual boxes.

Imperial moths are univoltine, meaning they have just one brood a year.  The final instars will be provided soil and leaf litter to crawl into where they will form their cocoons.  They will spend the winter in the garage and come out to the Butterfly House in time to emerge for the Butterfly Festival.  Then I suspect there will be a several wild and crazy nights in the trees at the Springfield Botanical Gardens.
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*You can see the action in the eggs and the caterpillar's first walk in this Youtube video.
More at Butterfliesandmoths.org

Friday, August 18, 2017

Rove Beetles

Rove beetle, 12 mm Philonthus caeruleipennis - REK
I recently encountered two different species of rove beetles, members of the Staphylinidae family.  This is the largest beetle family with over 63,000 species worldwide, an ancient lineage that has been around since the Triassic 200,000,000 years ago.  Question, where do you find someone to count 63,000 species?  I suspect it is graduate students.

Earwig, note pointed cerci - Wikipedia
Rove beetles most obvious characteristic is their short wing covers (elytra) that don't reach the lower half of the abdomen like other beetles.  They resemble earwigs until you notice they lack the pointed cerci pincers at the end of the abdomen.
Ventral view of Philonthus caeruleipennis - REK
They can range up to 1.4" but most are less than 0.4".  Both of my species measured 0.5" (12mm).*  Most of the common species live in decaying plant and leaf litter, under stones and bark or around the margins of streams and bodies of water.  The Philonthus caeruleipennis pictured above was found in a decaying Oyster Mushroom, a common association for the species according to Eric Eaton.  It is commonly found in forest, marsh and prairie litter (often riparian), and sometimes under the bark of logs.

Typically rove beetles have short elytra covering small wings that are seldom used.  Many have evolved to be flexible, able to used their narrow bodies to crawl into narrow places or to shorten their bodies to reduce their surface area to avoid dehydration.  The increased exposed surfaces and junctures in their body means they lose moisture more rapidly.  They overcome this by staying under humid detritus, leaves, and bark.  

Gold-and-brown Rove Beetle (Ontholestes cingulatus) - L Bower 
The advantage of hanging around for millions of years is the time to evolve to live in a wide variety of niches.  There are a wide variety of shapes and colors as demonstrated by Linda Bower's find to the right. 






Specialized lifestyles means that they can lose some now redundant body parts and save the energy needed to grow and use them.  Some species that live in soil and caves have lost their eyes.  Others no longer need long distance transportation to maintain their species and no longer have wings.  

As you might expect with such a large number of families, there is a wide variety of foods that various species specialize in.  While many are saprophytic including fungi feeders, others are predatory (fly larvae and even mosquitoes) and a few eat only plants.  To get even, the Laboulbeniales order of fungi are obligate ectoparasites, living on rove beetles, mites and millipedes.  They get their nutrition from the animal while not usually causing significant harm to the host.

Rove Beetle - Homaeotarsus sp.http://bugguide.net/node/view/1413817
My other rove beetle can only be identified down to the Homaeotarsus genus and even to that level I can't find any more details about its lifestyle.  With 63,000 species in the rove beetle family I suspect it will be some time before all of them get fully studied, more work for future graduate students.

Movie monster or rove beetle? - REK
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* I hope that the metric conversions don't bother you.  Most scientific articles use metrics so if we are going to continue to read about nature, we need to get used to it.

The University of Florida has a good in depth discussion on rove beetles in this PDF.









Wednesday, August 16, 2017

Walnut Caterpillars

Walnut Caterpillar, Datana integerrima  - Mort Shurtz

D. Integerrima in mass - Missouri University Extension
A while ago Mort Shurtz sent me this picture of a Walnut Caterpillar, Datana integerrima, that he found in his back yard.  When a moth species' common name is for the caterpillar, it means either that the cat is beautiful or obnoxious.  D. integerrima falls into the obnoxious category.  In their big years they tend to cover the trunks in large numbers, defoliate the trees and generously spread their frass around. 

Walnut Caterpillar Moth, Datana integerrima - Bob Moul
Although we have planted over 500 walnut trees in our riparian area within sight of our house, I have yet see Walnut Caterpillars on our trees or to photograph a Datana integerrima along Bull Creek.  At first glance it would be hard to guess that it was a moth or even would be capable of flight.  Its color is more handsome rather than pretty, more like a fine piece of wood furniture.  It has an orange fuzzy head and a black spot on its thorax.

Spotted Datana Moth - Datana perspicua
We commonly see its cousin coming to our deck light overlooking Bull Creek.  The Spotted Datana, Datana perspicua, has a similar color and shape but logically enough has a dark spot on it dorsal wing as well as sharper lines on its wings.  It feeds on sumac that is plentiful in the valley.

Yellow-billed Cuckoo - Joe Motto
Texas A&M cites some species of  wasps and flies that consume egg masses and larvae of Walnut Caterpillars, and many other insects and spiders prey upon larvae.  When disturbed, the caterpillars drop to the ground on a silk thread.  Birds don't make most of the lists of known predators and I suspect the fuzzy hairs of the Walnut Caterpillar serve as a deterrent.  I doubt that their large family gatherings would be possible if they were tasty and convenient for birds to eat.  Our Yellow-billed Cuckoo Coccyzus americanus, is the only bird listed as eating them, first reported in 1922.

Eastern Tent Caterpillar
Fall Webworm
















Fall Webworms and Eastern Tent Caterpillars are other moth species that form large communal nests early in life that would seem to offer a feast for birds.  They appear to be protected by their web, until we tear it up exposing the individual caterpillars.  The masses of caterpillars that "flock" together can serve as a defense only if a bird eating one will decide that they aren't tasty, either because of chemicals or the nasty effects of the hairs.  But where potential food congregates there is usually some predator that will develop a strategy for getting it.

Lisa Berger sent me some information about one predator, the Black-billed Cuckoo, Coccyzus erythropthalmus that specializes in these species.  The Birds of North America information on the cuckoo's digestion of caterpillars is well worth a read.
"The Black-billed Cuckoo is a notorious consumer of caterpillars, with a demonstrated preference for noxious species, including the eastern tent caterpillar (Malacosoma americanum), fall webworm (Hyphantria cunea), and larvae of the gypsy moth (Lymantria dispar). Observations of cuckoos consuming 10–15 caterpillars per minute are testimony to the great service this species provides in forests, farms, and orchards. Stomach contents of individual cuckoos may contain more than 100 large caterpillars or several hundred of the smaller species. The bristly spines of hairy caterpillars pierce the cuckoo's stomach lining giving it a furry coating. When the mass obstructs digestion, the entire stomach lining is sloughed off and is regurgitated as a pellet." Excerpted from The Birds of North America Online.
This cuckoo species is rare in the Ozarks and therefore not an answer to our outbreaks.  Birds of North America's map shows that we are just barely in the southern edge of its breeding territory.  That still leaves our Yellow-billed Cuckoo.  According to Allaboutbirds, "Yellow-billed Cuckoos forage slowly and methodically in treetops for large, hairy caterpillars.  (They) are among the few bird species able to eat hairy caterpillars. In the East they eat large numbers of tent caterpillars—as many as 100 in one sitting."

Yellow-billed Cuckoo in the treetop - Clark Creighton
When disturbed by a potential predator D. integerrima drops rapidly to the ground.  Since the cuckoo tends to forage higher up, the caterpillar can start the long slow climb back up the tree while the bird has had its fill of its siblings and leaves, ensuring the survival of the species.  But how does the cuckoo handle the hairs?
"Cuckoos and hoopoes (Upupidae) are also able to clean larvae from their setae by rubbing them on the ground (Payne, 1997;Kristin, 2001), but the best adaptation to feed on hairy caterpillars is found on several cuckoo species. In these species, the gizzard inner layer has evolved towards a soft, thick and non-keratinoid structure that allows the larvae setae to be kept inserted in the gizzard wall and to be regurgitated as mixed pellets of mucous membrane and setae (Gill, 1980)"  Birds as predators of the pine processionary moth.
If that doesn't sound very appealing to you, watch an Asian cuckoo in action in this video.  It rubs the caterpillar along the branch to wipe off most of the hairs as well as drain the intestinal contents before eating it.  No wonder we call them cuckoos!

Tuesday, August 15, 2017

Copperhead Bite

Copperhead after a swim
Copperheads are the most common source of venomous snake bites in the United States.  This is due to their numbers from successful breeding and their choice of habitat.  Like their cousin, the water moccasin (both are in the Agkistrodon genus) they generally prefer moist environments along water ways.  They also tend to be closer to human habitation, setting up home under sheds and woodpiles.  It is not often that you can see a video like we have below of someone being bitten.

As a rule, venomous snakes are not out looking to bite humans.  We are too big for them to waste their precious venom on but we do have a tendency to get in their territory frequently.  Copperheads respond to threats by freezing in place.  They consider being stepped on or picked up a hostile act and will respond appropriately.  Herein lies the tale.

Three friends were fishing and swimming in Bull Creek this June.  They watched a midland water snake cruising their fishing hole daily.  The last day of their visit a snake came swimming across the hole and one of them decided to catch it.  Lesson one: Most snakes can swim.

The midland water snake has dark bands around its body.  It tends to swim with just its head above water and frequently disappears under water in search of aquatic prey.  They are tan with brown even bands.  This one had bands that spread out down its sides- Hershey Kisses of a copperheadLesson Two:  Identify snakes carefully.


Our friend picked up the snake carefully by the tail.  He held it for a full minute, the snake  crawling near his bare ankles without biting.  When he tried to grab it behind its head he was bitten.   Lesson Three:  Copperheads aren't anxious to bite 190 pound bipeds unless threatened.

One to two hundred copperhead bites are reported every year in Missouri although there has never been a fatality.  I suspect there is under reporting as virtually every group I speak with knows at least one person who has been bitten in the past.  The weekend our friend was bitten two other copperhead bite patients were admitted to Cox Medical Center.  He is now back to normal after a day in the ICU with severe pain and swelling, 10 days off work, and $25,000 of antivenon.

Snakes are a part of our natural environment.  Copperheads pay their dues by eating rats and other vermin.  When they are around our houses, pets and children they are a safety hazard.  On the other hand, when they are out in the wild, respect their territory and leave them alone.

Incidentally, a copperhead bite led to the invention of the Weed Eater.*  In our case, the only good news was that his friends made a video of the event which serves as a cautionary tail- don't grab a copperhead by it unless you want to get bit.  Now if you are ready, go to this site.

 * George Ballas created the weed eater with a popcorn can and some wires attached to a lawn edger.  He was inspired by a gardener who was bitten by a copperhead while hand trimming around a garden.

Monday, August 14, 2017

Cute Jumping Spider

"They went that-away"  -  REK
Walking the gravel bar looking for fossils I saw something tiny jump among the rocks.  It was this bold little jumping spider searching for food.  Each jump is quick and it always landed on top of a small rock, a good perch to look around from.  After I took a number of photographs I got down to ground level to get a face picture and it tried to distract me by pointing in another direction - very clever spider!

Wolf Spiders (1) and Jumping Spiders (2)
It is important to get a full frontal face shot when possible to see the eye pattern.  The number of eyes and their arrangement can be compared with commonly available eye diagrams.  Unlike most other spider families, the Salticidae have flat faces with large eyes pointing straight ahead.  Large eyes can be an adaptation to gather light for night vision, but in this case they specialized for prey identification and measuring the range to land directly on their prey.  This explains its landing on top of a rock every time!

Like most spider families they actually have four pairs of eyes but the other two sets are on top of the head.  They provide lateral vision looking for movement rather than focusing on the object.  I tested this by moving my hand to its side.  Sometimes this made it jump but with a slight movement it would make a tiny hop, turning 90 degrees to face me.



Identifying spiders to species is challenging but this is the rare exception.  Even in the deep shade its metallic green color was impressive.  This is a male Emerald Jumping Spider, Paraphidippus aurantius, as confirmed on Bugguide.

"Look deep into my eyes, you slow human." - REK
Jumping spiders, Salticidae, are the largest family of spiders with more than 500 genera alone.  They are the rock stars of the arachnid world with lots of Youtube videos titles adding "cute."  So far none have created a music video but they just might crowd out the cat video craze with time.  Arachne.org from Australia describes "The courtship of some genera including Maratus the Peacock Spiders feature a complicated ritual of leg waving, toe-tapping, abdomen twerking, and wing flapping."

Part of their cuteness comes from the way they look up and watch you, especially those that people keep as pets.  Yes arachnophobes, some people actually keep them. 

 Tree of Life provides further details:
"Jumping spiders are charming spiders that look up and watch you. Their excellent vision allows them to hunt much as do cats, spotting prey from long distances, creeping up then pouncing using their jumping ability. Although a jumping spider can jump more than thirty times its body length, none of its legs has enlarged muscles. The power for jumping probably comes from a quick contraction of muscles in the front part of the body increasing the blood pressure, which causes the legs to extend rapidly much as in the toy frogs that hop when you squeeze a bulb."
Thus far I have not considered testing the strength of our marriage vows by bringing a "cute" jumping spider home.  More on that in a later blog?

Tick Trefoil


Desmodium flower 1/4" Missouriplants.com
Mark Bower sent us this picture of a tiny flower from the forest floor.  Barb thought it was a Desmodium and Mark got the same opinion from the Missouri Native Plant Society Facebook page but we sent it on to Linda Ellis.  She confirmed this but didn't have enough to try to identify it as to which of the many species it is.  They are pretty and dainty with a 1/4" flower now but just wait a month.

Missouriwildflowerguide.com
September is the time that they start to spread the seeds.  I know that all plants have their place, I just wish that my pant leg wasn't one of them.  Desmodium is also called tick trefoil, beggar's lice, stick tights, hitch hikers, and occasionally"@*%^$#".  There are 19 species in Missouri which can only be identified by getting close enough for their seeds to grab your clothes.  

 Seed pods - Missouri Extension
Their seedpods grow in strings that break off individually to increase the challenge of picking them off.  They act as triangular magnets attracted to cloth and hair, grabbing on with their tiny dense hairs.  They look and feel smooth except under magnification or my wife's watchful gaze when I return home.  Some can be scraped off with the back of a knife, others require individual picking.  They even sealed Smokey's eyes shut after a walk.


Desmodium 9, Smokey 0 - REK















When I scrape a cluster of seed off my legs, I try to tell myself that they are a great native plant.  They serve as a food source for deer and birds  Lots of insects such as weevils, beetles, leaf eating larvae and aphids eat them, many of which are then eaten by quail.  Best yet, they are the host plant for caterpillars of the Eastern Tailed Blue, Everes comyntas, and the Gray Hairstreak, Strymon melinus.  OK, I guess the trade off for a picture like Jon Rapp's below is worth a little scraping of my pant legs.

Eastern Tailed Blues - Jon Rapp
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Our favorite plant resources:
MONPS - Missouri Native Plant Society Facebook page can frequently identify a species.

Missouriplants.com lets you search by color and leaf arrangement.

http://www.illinoiswildflowers.info/  has encyclopedic information on our native species.  The quickest way is to Google Illinois Wildflowers and the species name.

Thursday, August 10, 2017

Cottonmouth Aggression


Western Cottonmouth  - Tom Spinker CC

We recently wrote about the death of a Northern Watersnake which was misidentified as a cottonmouth that was "coming after" a swimmer.  One of the most common snake myths that I hear is that cottonmouths (Water Moccasin) are aggressive and attack canoes, kayaks and people swimming and wading in our streams.  

Green area is our A. p. leucostoma- Wikipedia

There are three subspecies of cottonmouths, Agkistrodon piscivorus, in the US.  Our native Missouri species is A. piscivorus leucostoma (white-mouth).  They are mainly in Southeast Missouri sloughs and the rocky creeks of the Ozarks.  We haven't seen them on Bull Creek but I suspect they are here.

  MDC - Noppadol Paothong
A recent story by Francis Skalecky in the Springfield News-Leader addressed cottonmouths but I want to follow up on it. While they may be harder to intimidate, they are not out looking to waste their venom on humans, or kayaks for that matter. All of these are too big for a snake to swallow and once their venom is used, they can't subdue prey for several days while they restore the supply.

Research at the University of Georgia entitled Defensive Behavior of Cottonmouths Toward Humans tested their aggressiveness with three scenarios.
  • First they stood closely beside the snake with a snakeproof boot touching its body.  Of 13 individual cottonmouths tested, four attempted to escape, five gave some form of defensive display, and none tried to bite, although one individual feigned a bite during a strike. Only two of the snakes performed more than one defensive display.
  • Second scenario-  They stepped on the snake at midbody with enough force to restrain but not injure it.  Of the 22 that were stepped on either initially
    or secondarily, 15 gave defensive displays, including two that feigned bites.
    Nine of those stepped on were attempting to escape by crawling away and one bit the boot.
  • Third Scenario-  They picked up the snake at midbody with a pair of
    1-m snake tongs (Whitney Tongs) with a grasping handle that was modified to resemble a human arm and hand. A leather glove was fitted over the end of the tongs, with one extension covered by the thumb and the other by the middle finger. Hence, the glove could be closed around the snake’s body. A padded shirt sleeve was used to cover the remainder of the rod up to the handle.  Each treatment was carried out for 20 sec, and the behavior of each snake was recorded. 
    Of the 36 individuals held in the "hand" for 20 seconds, only13 (36%) bit the artificial hand, striking near the point of contact with the snake’s
    body.
I would not suggest that you do any of the above maneuvers with any snake.  This is unquestionably a dangerous snake, one to be respected like any other animal that can hurt or kill you.  They just want to be left alone as do we.  A frequent question we hear is "Is it illegal to kill a snake?" so here is the answer in MDC Discover Nature.

Missouri's Wildlife Code Protects Snakes

Few Missourians realize that all snakes native to our state are protected. The Wildlife Code of Missouri treats snakes, lizards, and most turtles as nongame. This means that there is no open season on these animals, and it is technically unlawful to kill them. There is a realistic exception, however: when a venomous snake is in close association with people, which could result in someone being bitten. We hope that more people realize that snakes are interesting, valuable, and, for the most part, harmless. 
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From Lisa Berger, a mother Cottonmouths instructions to the snakelings:  "Use venom only if you are being crushed, or if you need to subdue food; otherwise bite gingerly, and inject accordingly."