Nature Blog Network

Monday, October 20, 2014

Goldenrod Galls

New research has shown that bison feeding on the prairie increases the diversity of species even as it reduces the biomass of the grasses and forbs.  As Dr. Matthew Moran explained to Entomology Today, arthropod abundance and diversity was greater in bison grazed prairie than in control fields.
"Even though the bison reduced the amount of grass by 50% or more, the overall abundance and diversity of arthropod herbivores and carnivores increased significantly, especially among sap-feeders. In addition, Dr. Moran suggests that this may also be beneficial to birds and and other animals that eat insects."
Goldenrod stem gall - REK
We recently explored the Rotary Club Nature Park in Mountain View with our friends Jack and Marty Toll.  Marty showed their beautiful Butterfly Garden, a wooly field of native nectar and host plants sure to warm the heart of any leipdoptera.  Their goldenrod scattered through the field also demonstrated another way that species diversity is maintained by providing a home for insects in the form of galls. 

Stem gall with larva - REK
Larva closeup - REK

The round goldenrod stem gall above contains the maggot larva of Eurosta solidaginis .  These in turn can feed the predaceous beetle larva of Mordellistena (below).  According to Bugguide, "Apparently smaller galls are parasitized more often than larger ones; but the largest ones are eaten more often by chickadees and wood peckers."  Once again this illustrates the importance of goldenrod in the food web.

Beetle larva is gall - Beatriz Moisset
There are many species of goldenrod including the genera Solidago and Euthamia.  Goldenrods in general support a wide range of gall-forming insects.  The plants survive the stress while contributing to insect diversity and the food web.  There are over 50 species of gall forming insects, two thirds of which are midges in the family Cecidomyiidae.  The genus Rhopalomyia alone has 16 species which produce galls in either the bud, leaf, stem, rhizome, or flower-head of their specific goldenrod host species.
Flower head or rosette gall - REK
There are other species that produce a wide variety of goldenrod galls.  While the round or elliptical galls on the stem are easily recognizable, the flower head, bunch or rosette galls are stranger.  They produce a mass of leaves in a cluster, somewhat similar to the mass of twigs of a witch's broom growth on a hackberry.
"In addition to the gall makers we should consider all the parasitoids, predators and inquilines. The total numbers must be quite substantial. In some cases more than fifty percent of galls are parasitized; furthermore, it seems that for each species of gall maker there are at least three or more different species of parasitoids, inquilines, etc."  (
"Inquiline" refers to an organism that lives commensally in the nest or structure of another organism, usually for the purpose of sharing food or resources. This could be a small spider on a larger spider's web or caterpillars living in ant nests while sharing their honeydew, in the common parlance, a type of "friends with benefits."  Many inquiline species live in the structures produced by gall making insects.

A wide variety of moths feed on goldenrod, and wasps, spiders, birds and other predators use their larva.  A patch of goldenrod can contain a whole microcosm of life.  An incredible food web awaits the patient naturalist with curiosity and a hand lens or a good camera.  We will look at some goldenrod inhabitants and their predators in a followup blog.

Many of the gall forming species and their predators are found on the site.

Friday, October 17, 2014

Pelecinid Wasp

Pelecinus polyturator female
Sometimes a picture grabs me.  This one was sent to me by a friend of a friend and was taken when the creature had landed on the rim of his truck bed.  (My truck wasn't that clean when I bought it!)  She looks like one mean wasp, a creature that could get its stinger into your gall bladder!

Fortunately for us, she doesn't have a stinger, just an extended method of "laying" an egg.  This is a female pelecinid wasp.  They have elongated articulated abdominal segments (metasoma) with an ovipositor on the end.   You will notice that the "ankle" is thicker than the leg segment above or below it.  Also the antennae are very long, all typical of a female Pelecinus polyturator.

June beetle grub - REK
The extended abdominal segments are not just for show.  The female P. polyturator has to deposit her egg on a June beetle grub.  Her larva is parasitic and will feed on the grub as it develops.  The grubs burrow as deep as eight inches into the ground, so the female needs the long extension to reach them. 

P. polyturator male - Larry de March
Only the females are commonly seen.  The males are half their size, with the same long antennae and leg anatomy but with a shorter non-articulated abdomen.  Females don't need the males on a daily basis as they are parthenogenic, meaning they do not need to mate to produce fertile eggs.

The wicked looking abdomen probably serves to protect the wasp from curious humans but even if she used it in defense it wouldn't penetrate your skin.  It is more like a "Baby on Board" decal, so don't swat, just take pictures.

The June beetle grub is fascinating on its own, moving on its back by the use of hairs, its relatively useless legs flailing in the air.  See this previous blog.

Thanks to Brian Hoover for the picture that started this topic and to Larry de March for the use of his photograph of the rarely seen male. 

Wednesday, October 15, 2014

Life in a Goldenrod

While examining goldenrod for head galls, I noticed one of the heads which had rolled up leaves. These weren't the tight clustered leaves of the goldenrod head gall shown last week.  They remained green and flexible.

Aphids in rolled leaves
All of the rolled leaves contained lots of frass (insect poop) and many had 10 to 30 aphids clustered together.  There were scattered juveniles in the cluster, a real family affair.


A few of the leaves also had green larvae nestled in the frass.  When I removed two of the larvae, each had an aphid attached which I could pull away with my fingernail.  I sent the pictures to Chris Barnhart who identified them as syrphid fly larvae which feed on aphids.

Syrphid fly larva with an aphid.
Syphrid flies are also known as hover or flower flies, named for their habit of hovering over flowers while nectaring.  Their larvae may be saprophytic, feeding on dead plant and animal material but some species are insectivores, eating aphids and other small plant eating species.  Some species are important as pollinators and others have commercial pest control value.
"Larvae of predaceous species feed on aphids and other soft-bodied insects and play an important role in suppressing populations of phytophagous insects. Larvae move along plant surfaces, lifting their heads to grope for prey, seizing them and sucking them dry and discarding the skins. A single syrphid larva can consume hundreds of aphids in a month."
Aphid lunch

All of this simply demonstrates that there is a lot more life in a goldenrod than initially meets the eye.

Monday, October 13, 2014

Glowing Mushrooms

 Panellus stipticus - Susan Farrington
The Mingo National Wildlife Refuge foray of the Missouri Mycological Society last weekend was a combination of great food, mushroom collecting and identification, great food, fellowship, and did I mention wonderful food? The highlight of the fungal finds was really a high-light, glowing brightly in the darkened storeroom. Susan Farrington found it and tells it this way.
"Coolest mushroom I found today at the Mingo Foray: bioluminescent Panellus stipticus. This thing glows like crazy!! (Much stronger than the jack-o'-lantern). 30 second exposure at 3200 ISO, F 8.0."
P. stipticus - Susan Farrington
Known by the demeaning names of bitter oyster or the astringent panus, Panellus stipticus is found in Asia, Australasia, Europe, and North America. The eastern U.S. specimens show a bioluminescence not found in the west or other continents. A single dominant allele found on genetic analysis controls this function, so it apparently evolved this trait east of the Rockies.

P. stipticus - Susan Farrington
P. stipticus has several other interesting traits. It has been shown to detoxify some environmental pollutants and is being studied for a potential role in bioremediation. It has a slightly bitter or astringent taste and another name, stiptic fungus, comes from its use in China to stop bleeding. There is much more information including the details of bioluminesence in this extensive Wikipedia article.
Jack-o'-lantern headed to the bathroom -  REK
When I think of bioluminescent mushrooms, the jack-o'-lantern immediately comes to mind. Last year I stood in a crowded blackened bathroom at Bull Mills with other like-minded adults for longer that I care to admit and still never saw a glow. Susan has an answer for this.
"You need a very young and fresh jack. Wrap it in a damp towel in loose plastic until dark. Take it to very dark place and wait for eyes to adjust. I found if I look just to the side of if, you can see the faint glow. By contrast, we could see the Panellus glow brightly from six feet away the second we turned the lights out!"
Jack-o'-lantern, Omphalotus olearius, is a much more impressive mushroom in daylight. Although I will probably stand again in the future in a darkened room with consenting adults, staring at it, I suspect P. stipticus has diminished any future thrill.  P.S.- Our friend Georgia took home this "floral" decoration below from a dinner Sunday night and reports, "I checked it out as soon as we got back and after about 3 min in the dark it had quite a light green glow on the gills. Pretty cool."
Decorating with fungi
P. stipticus photographs by Susan Farrington of the Missouri Department of Conservation. She is the Natural History Biologist for the Ozark Region.

Friday, October 10, 2014

Skiff Moth

Yes, it is a caterpillar! - Georgia Pozycinski
I received these pictures from our friend Georgia with the following note.
"Joe found a "new" bug stuck on the side of our dog water bucket this morning. He was stuck to the side, kind of like a slug. Any idea what he is? Some kind of caterpillar?"
Underside - Georgia Pozycinski
OK, time for true confessions.  I guessed a slug and my first attempts to find it failed.  I sent it to my guru Chris Barnhart who immediately nailed it as a skiff moth caterpillar, Prolimacodes badia, of the family Limacodidae.  I guess that is the value of studying in school until you get a PhD instead of an MD.  Anyway the pictures were very convincing.  "This family is incredible!"  in Chris's words.
"If you'd like to see one of the most bizarre, colorful, jaw-dropping, head shaking menageries on earth, Google 'slug caterpillars' images. Some toy company should really make a line of collectibles."
It is hard to imagine this is a caterpillar, but this Youtube video will help you believe when you see it move.  Unlike most caterpillars with tiny hook like feet, slug caterpillars glide along on tiny suckers on their undersides.  They remind me of aerodynamic tanks sliding along with no exposed surfaces.

Measuring just over half an inch long, this caterpillar defines the term "low profile".  It feeds on a wide variety of plants including oak, poplar, willow,  cherry, chestnut, hop hornbeam (Ostrya virginiana), and willow.  There may be 2 generations and they overwinter as pupae. 

Finger lickin' badi - Chris Barnhart
The adult moth is no slouch either, an unmoth-like creature that will come to your porch light but is easily overlooked.  Its name "skiff moth" may refer to the shape of the caterpillar or even to the moth below.


Missouri is at the far western edge of P. badia's range.  Like most insects, there is very little further information on this relatively common creature, adding even more mystery.  Ain't nature wonderful?

Monday, October 6, 2014

Fuzz on the Kale


My editor (wife Barb) keeps me constantly entertained with her discoveries in the garden.  This time it was clusters of tiny fuzzy spots stuck on the underside of lots of our kale leaves.  The whole cluster measured only an eighth of an inch, a jumble of oblong fuzz balls.  We put the leaf fragment in a plastic box and left it on the dining table for a few days.  Note: I am blessed with a wife that will tolerate road kill snakes and blue heron heads in her freezer.  Since she accepts them, what problem is a little plastic Gerber baby food box containing insects sitting beside the salad bowl?
Braconid Wasps
When we next checked it there were tiny 2mm black specks on the lid.  When I opened it, they immediately flew out.  The next day there were more and this time the box went in to the freezer for a few hours before opening it.  These turned out to be tiny wasps.

I sent the pictures to and got a rapid response from Ken Wolgemuth.   He identified them as braconid wasps (Braconidae)  in the subfamily Microgastrinae.  He explained that these are "individual cocoons that were spun by the wasp larvae that were consuming the host (e.g. caterpillar) that was feeding on your kale. They then emerged from these cocoons as the adult wasps you are seeing now."
Braconid wasp
The Braconidae family of wasps numbers over 17,000 species and counting.  They are parasitic like their larger Ichneumonoidea wasp cousins, using the larvae of beetles, flies, butterflies and even aphids to feed their young.  Once they crawl out, they spin their cocoons for protection until they emerge as adult wasps.

Cabbage white - Bob Moul
These clusters were really good news.  We have lots of cabbage white butterflies, Pieris rapae, constantly hovering around the kale.  They are the most common butterfly in North America, an unwelcome European import which arrived around 1860 and is now on every continent on the globe except Antarctica.

They are a hearty breed, the first to emerge in the spring, flying from March through November.  In addition, their reproductive success comes from the fact that they may have 7-8 hatches a year and the wide range of host plants they can raise their young on.

Cabbage white caterpillar - Wikipedia- CC
They lay one egg on each available leaf of their host plant. They eat predominately plants in the mustard family, (Brassicaceae) including cabbage, broccoli, and our kale as well as dandelion, red clover, asters, and mints.  They seem especially addicted to our leafy garden plants, chewing holes in the kale leaves until they look like a sieves. 

Cabbage white pupa - Bob Moul
The pupae of the cabbage whites are green or brown with points on the ends, resembling a dried up leaf. The last batch of caterpillars hibernate over the winter as chrysalids and hatch into adult butterflies in the spring ready to start the cycle again.

We have learned to embrace these little fuzzy spots on the kale leaves, wishing them great reproductive success as they munch away on the innards of the invasive caterpillars.  We can almost forgive their cousins for occasionally attacking caterpillars we raise at the Butterfly House.

For a graphic example of Brachnoidae larvae emerging from horn worms, check this Youtube video.


Sunday, October 5, 2014

Spiny Oak Slug

While I was volunteering at the "Bear Aware" table at MDC's Great Outdoor Days at Bois D'arc CA, a young naturalist named Timothy brought up this caterpillar, one of several like it he had found.  He has been hunting for caterpillars "for a long time" and raises them at home to adulthood.  This degree of sophistication at his age is quite impressive.

His find is a spiny oak slug caterpillar, Euclea delphinii, a colorful creature which comes in a remarkable variety of different colors.  Bright colors are frequently a warning to predators that "I taste bad" or "I can hurt you".  In the case of E. delphinii, it is the latter as those hairy spikes have a fluid that can cause a stinging sensation.

Another color -  Kevin Firth
While many larvae of lepidoptera eat only a limited species of plants, the oak slug relatively omniverous.  It eats " a variety of deciduous trees and shrubs, not limited to: apple, ash, basswood, beech, birch, blueberry, cherry, chestnut, hackberry, hickory, maple, oak, poplar, sycamore and willow," (Wagner, 2005*).

...and another color,  - Jon Rapp
and another! - Bob Barber
There are a number of different species of "stinging caterpillars".  The buck moth and the colorful io silkworm moths have this feature as well as the saddleback caterpillar and the hag moth, coming soon to the blog.  They have in common specialized hairs.
"Stinging caterpillars possess hollow quill-like hairs, connected to poison sacs, that are used as defensive weapons. When these hairs are touched they break through the skin releasing the poison. Reactions can range from a mild itching to the more severe pain, dermatitis, and even intestinal disturbances."  University of Kentucky
Slug moth caterpillars have a unique way of traveling with a wave-like motion,  They can leave a sticky trail not unlike a slug.  This is produced by the suction cups on its eight abdominal segments, replacing the usual prolegs of other caterpillars.

While finding the caterpillars requires diligent searching skills like Timothy's, the cute little (10 mm) moth can be found occasionally on the siding by our deck light.  Once mated, the females lay their eggs on leaves, and generally produce two generations of offspring a year from Missouri on south.

*  If you are interested in caterpillars, Wagner's Caterpillars of Eastern North America is a good place to start.