Paw Paw

Paw paw fruit

After a series of late freezes have destroyed the Paw Paw crop we were excited to see lots of fruit in our Paw Paw grove.  My excitement diminished today as I saw a number of broken branches, evidence that the competition is getting to them before they are ripe.  Squirrel, bear and raccoons are all in line as the summer draws to an end.

Paw Paw (Asimina triloba) is a native tree which produces fruit two to six inches long.   It has the flavor of an over ripe banana and when mature you may smell them before you see them.  It has 1/4" seeds and a custard-like pulp which is good on ice cream, paw paw bread or even eaten raw. 

The small tree is easily identifiable by its distinctive leaves.  They are alternate, single veined and widest close to the tip.  The leaves are among the largest in our forest, ten to twelve inches long, four to five inches wide.  In the early spring, before or just as new leaves are coming out, it produces a distinctive maroon flower.  This early spring blossoming leaves it vulnerable to late frosts.

Paw paw leaves

Paw paw tends to grow in well-drained, fertile bottom-land soil.  How our grove developed up on top of a ridge a mile from the creek remains a mystery.  The density of the 40 trees is more understandable as they grow by suckering of the roots, meaning that they are likely all genetically identical.  The grove is close to a hollow tree that has been a refuge for bears over the years.  They or some other animal may have transferred the seeds in the way a large mammal "moves" big seeds.

Paw paw girls- 2003

It doesn't look like we will have a big harvest like the one in 2003.  I can only show the ones that survived the morning as over half were shoved into mouths as we harvested them.  I suspect this year we will have some really big raccoons and a few bears with green gooey smiles.

Mud Daubers

A Springfield News-Leader article by Francis Skalicky of the Missouri Department of Conservation (MDC) on wasps led me to some interesting information.  It turns out that not all mud daubers are created equal.

Organ pipe dauber nest

The male organ pipe mud dauber (Trypoxylon politum) is not only a master mason but a dedicated family man.  After constructing the detailed nest, a family affair, the male stays to guard the nest against parasites while the little lady is off shopping for spiders to feed the future kids that are currently resting in the egg.  This trait, more recent evolved in human husbands, is not all that common among male wasps.

Black and yellow dauber nest

The black and yellow mud dauber,  Sceliphron caementarium, is more like my generation, leaving the feeding of the kids to the female.  Their nest is built built of parallel tubes, later plastered over to form a large and unsightly lump.  Once sealed, the adults leave the kids on their own.  Consequently there are several  insects that will parasitize their nests.


The blue mud dauber Chalybion californicum is a metallic blue species that preys primarily on black widow spiders. It does not build a nest, but uses nests abandoned by other mud dauber wasps. It doesn't carry mud but only water which it uses to renovate their previously used nest.  Like other mud daubers, it is rarely aggressive. Think about it- doesn't build new nests, doesn't attack and harvests black widow spiders. Sounds like a good household pet to me.

There is a summary of these wasps in the Discover Nature Field Guide.

Black Vultures Fledge- They're Baaaack!

August 23- You again?

I stuck my head in the Black Vulture nesting stall to see if I needed to clean out anything and there the chicks were, looking none the worse for their outing.  If I hadn't gone all over the stall the day they fledged I would have thought I had overlooked them.

I had assumed that like robins and bluebirds, once they leave the nest they are gone.  The hawkmountain.org site says that they fledge at around 10 to 14 weeks but remain dependent on their parents for much longer.  Sometimes they are still being fed by their parents eight months later.  They also may hang with their parent's social group for several years. With this late teenager behavior I almost expected to see an X-box in the stall.

The hawkmountain.org  site has extensive information on black vultures.  Stay tuned for more adventures!

Black Vultures Fledge!

Last day at home- Click to enlarge

For those of you who have been following the series on the Black Vulture chicks growing up in our barn, they are now coming to a sky near you.  I took these pictures on August 15th, 56 days after they hatched.

The egg discovery was covered in a May blog and their hatching in the June 20th entry.  They had grown up considerably since they were fuzzy little - well medium sized - balls of fluff.

Video Outake

As you can see now their fluff was falling off by the handfuls.  They walked around the stall paying attention to me only if I stepped in to get better pictures.  By now they would only raise their wings but no longer bothered to hiss at me.

Two days later I was headed past the old barn when I noticed black birds in the open center portion  As I neared I saw two turkey vultures fly out the other end, then two black vultures.  They were followed by the smaller chicks, awkward in flight and flapping rapidly like ducks.  They were able to gain altitude across the field and clear the distant tree line.

The barn was built before 1900 and has seen its better days.  One day it will collapse, hopefully long after we are gone.  We have a picture of Christopher Columbus Meadows holding a beautiful horse beside it.  It has stored our equipment, housed our harvested gourds and dried the garlic from its rafters.

Barn Swallow

It also serves as a nursery.  Resident wood rats chew on gourds and the occasional garlic.  A ground hog has taken up residence beside it and undoubtedly has maternal instincts.  A colony of barn swallows annually raise chicks that peer over the nests at us as the parents swoop through, chattering their protests that it is their barn.

With all this history, I think our favorite memory will be raising black vultures.  We will always wonder which vultures circling the skies are "ours".

Note:  Some day this fall we will post a video combining their nursery days.

Mushrooms of August

In Europe they hunt truffles with trained hogs or dogs but you have to feed and care for them.  At Bull Creek, I have Barb who can spot mushrooms while riding along on her ATV and she feeds and cares for me.  What a deal!  Editor's Note:  He is such a lucky guy!

Two-color Bolete- Click to enlarge

Monday's tour produced six species including two nice batches of Oyster mushrooms, a culinary treat.  We also found these beauties, Two-colored Boletes (Boletus bicolor).

Even with a distinctive looking mushroom like this one, identification is time consuming for a beginner.  Beginning with a careful inspection of the gills, pores or other methods of spore production, you then focus on consistency, texture, odor, bruising and other features.  Sometimes the final identification requires microscopic examination of the spores.


Two-colored Boletes are a little easier to start with.  The cap is 2-6 inches across and varies from dark red to almost pink.  The under surface is bright yellow with tiny pores packed tightly together, hard to see with the naked seventy year old eye.  The stalk is thick and very firm, a dark red which fades to yellow near the cap.  As is true throughout nature, colors can vary at times.

These are common mushrooms which show up from July to October and are usually found under oak trees, just as we found them.

All mushrooms are edible - once - some only once.  Many mushrooms will make you wish you hadn't eaten them but aren't fatal.  Occasional individuals may be sensitive to edible mushrooms including even morels.

"Edible" in mushroom reference books means it is safe to eat but says nothing about taste.  In theory, cardboard is edible.  This Two-colored Bolete is rated as choice.  Most of the mushrooms which could be confused with it are edible but I passed on it.

We never eat a mushroom unless we have learned to identify it from an expert who has eaten it in the past, and is standing in front of us looking healthy.  At least it made a great picture.

Tobacco Hornworms

Tobacco Hornworm on Datura

Barb identified these dreaded tobacco hornworms on a Datura "Moonflower" plant we acquired from Larry Wegman.  These and their near kin, tomato hornworms, are frequently described with scorn by visitors to the Butterfly House.  Both varieties are major pests on tomato plants but I think they deserve a little better press.

In spite of the tobacco in its name, Datura species plants are also a hornworm favorite.  The genus Datura includes Jimson weed and various thorn-apples (see the thorn-apple in the picture).  Datura are members of the Solanaceae family, which includes tomatoes, potatoes, eggplant, tobacco, petunia and even the deadly nightshade. 

Carolina Sphinx Moth- Wikimedia

The tobacco hornworm, Manduca sexta is the caterpillar of an attractive moth of the Sphingidae family that includes hawk moths, sphinx moths and hornworms. Its adult form is called the Carolina Sphinx Moth. They are rapid fliers and hover while feeding like a hummingbird.

Because of their large size, short life cycle and ease of feeding they are used in research settings as well as classrooms. Research includes neurobiology, flight mechanisms and larval nicotine resistance. Given their contributions to research and their habit of eating tobacco, I can almost forgive them for chewing the occasional tomato.

Read more: Datura and Hornworms | eHow.com http://entomology.unl.edu/k12/caterpillars/hornworm/hornwormpage.html

Incredible Osprey

Osprey- MDC

Dan Crane sent me this arkive.org link with footage of Osprey catching fish.  What I am sure is just business as usual for the bird is incredible to me.  The last catch shows it hauling out a fish twice its size, taking off from being completely submerged and carrying its prey in one claw!

Osprey are the only raptor that plunges into the water to catch its prey.  The fact that they can then take off, let alone with a large struggling fish is impressive.  Some of us can't always hold a fish long enough to take out the hook!  Osprey have special adaptations which allow this unique fishing style.

"The Osprey is particularly well adapted to this diet, with reversible outer toes, sharp spicules on the underside of the toes, closable nostrils to keep out water during dives, and backwards-facing scales on the talons which act as barbs to help hold its catch." (Wikipedia)

Last fall, Mike Kromrey pointed out an Osprey flying over Valley Water Mill.  Never common breeders in Missouri, their numbers were apparently reduced even before DDT took a toll on their population.  Like other species at the top of their respective food chain, they are vulnerable to toxins accumulated in fish.  We are seeing more Osprey in recent decades due to the reduction of pesticides and the development of reservoirs. (MDC)

More general information on Osprey can be found at this natural history site.

Mad Hat Insect

Treehopper helmet- shortsharpscience

An e-mail from Kevin Firth introduced me to treehoppers with their weird "helmets".   For those of us new to treehoppers, they are in the Membracidae family which is related to cicadas and the leafhoppers.  These are sap suckers, which penetrate wood with their sharp beaks.

The excess sap is concentrated as honeydew which attracts ants.  Aphids also produce honeydew and some species are actually farmed by ants which bring them in at night to protect them, taking them out during the day to resume farming.  Like some other insects including Lycaenidae butterfly caterpillars, some leafhopper species are protected from predators by the ants who know a "sweet deal" when they see it.

Treehoppers have so-called helmets which are appendages attached to the the back of the pronotum or first thoracic segment.  Think of it as just above and just between your shoulder blades if you were suddenly morphed into an insect.  These helmets come in a fantastic variety of shapes as you can see here at Bugguide.net.

Treehopper anatomy rewrites the standard description of insects. It includes a pair of legs on the three thoracic segments and a pair of wings on the second and third segment.  Wings on the first thoracic segment were present on some ancient treehopper fossils but are thought to have disappeared around 100 million years ago by the loss or repression of a functioning Hox gene.

The New Science blog shortsharpscience describes recent research on these helmets.  The new report has found that the helmets of treehoppers are actually a jointed appendage on the first thoracic segment (pronotum).  This is thought to be due to a reactivation of the Hox gene, revising what would have been a wing.  Since it isn't functional for flight, bizarre shapes are possible.

The science behind this is as fantastic as some of the helmet pictures.

Widow Skimmer

Widow Skimmer- Click to enlarge

Maybe it is just a slow news day but I wanted to post something beautiful.  This dragonfly lit on a garden pole and remained for some time.  I  e-mailed the pictures to my local guru George Sims and got his usual prompt ID, later confirmed by his cohorts at Odonatacentral.org/.

This is a Widow Skimmer (Libellula luctuosa), a dragonfly in the King Skimmer group.  They are a common dragonfly found across most of the United States.  Our specimen is a male, identified by the broad white spots in the mid wing.  This is best seen here in the side view but are easily seen when they are flying.  They are slow flying for a dragonfly and "easy to catch"- relative to say a hummingbird?.

They lay their eggs in the water, preferably pond or pools, and their larvae (naiads) feed on small aquatic insects.  The last molt reveals the adults complete with a set of wings.  They then feed on small flying insects, mate, drop their eggs and the cycle begins again.

Don't you love a story with a happy ending?

Good Parasites II

In Good Parasites I, we asked you to "Imagine what would happen if a destructive caterpillar had no natural parasites. 

Gypsy Moth- Wikimedia

Consider the success of the gypsy moth, Lymantria dispar.  It has spread across Eastern North America in the last hundred years and seems unstoppable.  During periodic population surges of the caterpillar, they cause the death of thousands of acres of trees by defoliation.  Most birds avoid the hairy caterpillars.  More importantly, they left all their normal parasites back in Europe and Asia when they made the trip here so they have no consistent parasites to control their numbers.*

In the absence of an effective native parasite, more than 45 foreign species have been introduced in a futile and occasionally desperate attempt to control the gypsy moth.  One tachinid fly,  Compsilura concinnata, was introduced as a known parasitoid of the gypsy moth and other introduced species such as  the satin moth and brown-tail moth.

Compsilura concinnata

  The  gypsy moth is univoltine (undergoes one generation per year), but the flies are multivoltine, having three to four cycles a year.  This means that only one cycle will feed off gypsy moth larvae and to survive the year, they have to find other caterpillar larval food sources, attacking species which pupate later.  Also, their larva must overwinter in a larval host.  Since the gypsy moth overwinters in the egg, Compsilura has to find another host. 

Some of the alternate hosts are garden pests such as the cabbage looper, Trichoplusia ni and the imported cabbageworm, Pieris rapae L.   Unfortunately, other hosts include swallowtails, Nymphalidae (brushfooted butterflies) and Saturniidae (giant silk moths).  Parasitism rates can be as high as 81% in the cecropia moth and 68% in the promethea moth.**

The lesson of all this-
"A Good Parasite is hard to find,
you always get the other kind.
Just when you think he is your pal,
You look for him and find him fooling 'round some other gal"
                  - with apologies to Eddie Green.

*    Missouri Natural Areas Newsletter Vol. 11 No 1 2011
**  University of Minnesota 

Good Parasites

Black Swallowtail Parasite- Barnhart

We recently wrote about parasitic wasps which lay eggs on caterpillars, hatching larvae which feed off the caterpillar and usually kill it in the end.  They are a major cause of caterpillar mortality.  We have special mesh at the Butterfly House sized to prevent most of these small wasps from getting to our cats.  We tend to hover like parents over the cats while wishing the were no parasitic wasps and flies anywhere.  We need to be careful about what we wish for.

Parasite has become a derogatory word.  It is used to describe con men, loan sharks and even a relative who moved into your basement "for a few days" and is still there two years later.  Who ever heard of a good parasite?

Parasites are actually an important part of nature.  Just as coyotes and foxes have cycles in the control the potential hordes of rabbits in our fields, parasites control the reproduction of their specific host species.  If they kill too many caterpillars, they will face extinction.

Variable Oakleaf caterpillar-FIDL

Sometimes the system gets out of balance.  The variable oak leaf caterpillar, Heterocampa manteo, is a common larva of a rather undistinguished moth.  It eats the leaves of many species of trees but especially attacks oaks.  Occasional heavy infestations can affect millions of acres and extend over hundreds of miles.  Twice in the last 30 years a swelling of their numbers has defoliated 7-8 million acres in Missouri. Although they may slow the growth of an individual trees, they rarely causing long lasting damage.*

Why they have big years is unknown but you can be sure that their parasites have greater numbers the next few years.  This is an important factor in controlling a large outbreak.  Fortunately, they have lots of parasites which serve to drastically reduce their numbers back to normal.  The Forest and Insect Disease Leaflet (FIDL) -no government pun intended- gives a lot more information.

"In years following large infestations, the egg parasites Trichogramma sp. and Telenomus sp. may kill 90 percent of the eggs. Nearly all egg masses have some parasitized eggs; only the eggs concealed within a cluster escape. This high level of parasitization, plus the failure of many prepupae to pupate in the spring, appear to be the major reasons for lack of consecutive heavy defoliations.
At least seven species of larval parasites attack variable oakleaf caterpillar larvae. The most important species are Diradops bethunei Cress (Ichneumonidae), Protomicroplitus schizurae (Braconidae), and Lespesia schizurae (Tachinidae). Combined larval parasitization may kill 90 percent of the larvae."

The lesson of all this- sometimes you really need good parasites.  Just imagine what would happen of a destructive caterpillar had no natural parasites.  Stay tuned for the exciting sequel,  Good Parasites II

* See the latest Missouri Natural Areas Newsletter

Making Connections

Kevin Firth, a butterfly wrangler and docent for Friends of the Garden allowed me to print this story for our blog.

Green June Beetle - Continis nitida

The Green June Beetle is a large scarab that usually starts to show up about the same time as the more infamous Japanese Beetles that we all know and love.  The Green June Beetle (GJB) is a native though, and generally occurs in much lower concentrations than the invasive Japanese Beetle.  I have seen only a few this year, but several summers ago, we experienced a rather large population of these beautiful scarabs (at least in my backyard).
  

The GJB is a noisy and not particularly agile flier--they sound like a B52 when on the wing.  I remember trying to mow my lawn one summer as an emergence of these beetles was underway in my backyard and actually being forced to stop and wait for the emergence to end before finishing the task--there were beetles slamming into me from all directions.  

The GJB larvae, like many scarabs, lives in the soil and feeds on the roots of plants, particularly grasses.  At that time, I wasn't sure what they were, and a quick search of Bugguide gave me the answer.

Scolia dubia- Wikimedia

I also noticed, about the same time, a beautiful wasp visiting the flowers in our landscaping.  This turned out to be Scolia dubia  and there was a good reason that I was seeing a bunch of these wasps about the same time that I saw the Green June Beetles.  Scoliid wasps are parasites of scarab beetles, and Scolia dubia specializes in parasitizing the Green June Beetle.  The adult females will dig to find a beetle grub, sting it to paralyze it, and lay a single egg on the grub.

While most of the wasps are observed nectaring on flowers, I have observed these wasps (presumably females) flying low over the yard, landing, and disappearing into the ground.  Editors note:  I would guess that they are leaving their pickles and ice cream nectar to lay a few eggs.

Giant Leopard Moth

Giant Leopard Moth

One advantage of being in Master Naturalists is that friends bring you lots of interesting bugs and plants to identify, a game called "Stump the Chump".  I sometimes have to remind them that "Master Naturalist" is an organization, not a degree.

Larry Whiteley brought this Bass Pro special today.  Fortunately he he had found a uniquely colored moth with an interesting story.  The Giant Leopard Moth, Hypercompe scribonia, is very distinctive with dramatic dark ovals and circles on its dorsal forewings resembling a leopard's spots.  This specimen was long dead so I livened it up on a floral arrangement.

Caterpillar Defensive Position- Wikimedia

Also known as the Eyed Tiger Moth, it is a member of the Arctiidae family which includes Tiger, Tussock and Lichen moths.  Its beautiful hairy caterpillar is related to the Woolly Bear caterpillar, touted as a forecaster of winter weather.  The Tiger Moths get their name from the bold bands of various colors on their dorsal wings.

Tiger Moths have a unique defense against bats, a formidable predator during their nocturnal flights.  They have long been known to produce ultrasonic sounds but now we know a reason why.  A Discover Magazine blog describes sounds the moths emit as interfering with the echolocation system of bats.  We can think of it like a fighter plane jamming a missile's radar signal.  This tactic greatly reduces the bat's successful rate of moth captures.

New studies of bat echolocation from Brown University add to the wonder.  They describe how a bat can isolate the echos of a small insect amidst all the echos from the environment (tree branches, leaves, wires, etc) and those of other bats. Since the attack sequence of a bat lasts less than a second, the moths have to react fast.  Fortunately, the moths can produce up to 450 clicks in one-tenth of a second.