Tuesday, December 11, 2018

Hattie's Scarab

Hattie's Scarab
I received this photograph from our friend Courtney who found the insect with her 3 year old assistant Hattie. They sent it in to INaturalist and got a tentative ID of Bolbocerosoma bruneri. That would put it in the Geotrupidae family, the Earth-Boring Scarab Beetles, EBSB, (also called dung beetles). 

B. bruneri - Marci Hess cc
I would agree with the genus Bolbocerosoma but have reservations on the species. All the photographs of B. bruneri on Bugguide show a thin curved black line on the thorax immediately behind the head which is missing in the picture above, so I am going to stick to Bolbocerosoma sp which gives us 12 species to choose from in the USThey all have in common the orange pronotum, black markings and five deep punctuate grooves on their elytra.

EBSB with its mound - Ag.Purdue.edu
EBSB have a very interesting life cycle. They burrow tunnels into the ground, some up to 9 feet deep. They may have multiple chambers at the bottom and the opening on top frequently has a pile up of dirt like a miniature prairie dog mound.  They deposit an egg at the bottom and then food above it forming a plug. This can include collected feces, decaying plant material, and fungus. The adults do not care for their young.  When grown, the grub will pupate, the adult emerges and climbs to the surface to fly off, probably relieved to be out in the fresh air.

They soon however return to the same old diet, eating decaying material and fungus and  and are often found on dung piles or compost heaps. Adults come to light which probably explains the one on Courtney's porch. Once you get past the "yuck" factor, remember that they are an earth-friendly species, similar to a vulture in recycling carbon and nitrogen from dead and decaying material into the soil. You didn't have any other plans for that dung, did you?

Friday, December 7, 2018

Life in a Walnut Husk

We were collecting walnuts to make walnut ink when I discovered life living under the husk.  It turns out that the space between the nut and the rind is a busy place.  These little wigglers might have given the normal observer a bad case of the heebie-jeebies but they only piqued my curiosity.  These are the larvae of the walnut husk fly (WHF), Rhagoletis completa.

Husk fly eggs in groups of up to 15 are deposited under the outer husk surface and hatch after five days into little white maggots. Older maggots turn yellow with black mouthparts.  The maggots feed inside the husk, gradually turning the husk mushy and black. After feeding for a month, the maggots drop to the ground and burrow into the soil where they will spend the winter as pupae.

Walnut husk fly - wsu.edu
"The adult is about 1/4 inch (6 mm) long, slightly smaller than a housefly. It has large, iridescent, greenish eyes, a tawny  brown body color and banded wings. It has a yellow spot on its back. Its conspicuous wing markings make it easy to identify. The female is larger than the male and its abdomen is more pointed." Washington State University also has  more information on WHF.

Husk fly male - Don Loarie
WHF gets no respect on the internet.  The maggots' feeding discolors the nut shells and makes the husks hard to remove. Early summer husk fly infestations also can stunt nut kernel development.  They can occasionally attack nearby apricot and peach tree fruit.  Most references are to methods of killing them and preventing the spread to commercial walnut crops.  A number of tactics are described to combat them including use of Sevin and malathion, which can affect a wide variety of innocent insects.

Damaged walnut husks laying on the ground may host other insects.  I have found other insects and tiny spiders hiding inside damaged husks and on a WOLF field trip while looking for husk fly larvae we found this tiny winged creature pictured here which I couldn't identify.

I recently found some other even more mysterious critters, but you will have to wait for them in another blog.  Speaking of tiny creatures, A Chaos of Delight has hooked me on "mesofauna" - photographs and stories of the wide variety of 0.1 mm to 2mm creatures living in soil.  It is addictive so enter at your own risk.

Wednesday, November 14, 2018

Tiny Mushroom

Someone asked me if I hunt and I answered "no", then stopped to think about it.  I do hunt but it is for interesting plants and insects.  Birders "hunt" birds and many mycologists hunt mushrooms, neither group intending to eat their prey.  Here is Mark Bower's description of a September "hunt."

"I had been walking in the woods for 2 1/2 hours looking for mushrooms to photograph. The woods were dry, and I had only taken one picture all morning. As I was leaving the woods, I noticed two small mushrooms growing together on a moss-covered log. I assumed that they were just the usual boring brown-capped Pluteus species which are very common, and not worth stopping for. On closer inspection, however, I noticed the scaly appearance of the cap, which would be very unusual for Pluteus.

Spore print

This prompted me to get on my knees and closely inspect it. To my surprise, the stem appeared to be streaked with purple. Multiple photographs were taken and a spore print revealed pinkish spores. With this information, and after reviewing my books, using keys, etc., I had no clue. I then put the info on the MOMS Facebook page. The genus Entoloma was suggested as a possibility.

The color of the spores is one of the distinguishing traits used to identify mushrooms. There are a lot of ways to make a spore print but the basic method is placing the underside of the cap on a surface and keeping it moist to encourage the spores to drop.  It helps to have a dark and light surface to contrast against the spores which may vary between white or pink to dark brown.  

I then posted it on Mushroom Observer, which is a website which is reviewed by mycologists, like Bugguide for Fun-guys and gals.  My boring little mushrooms were identified as Entoloma tjallingiorum, and even though I can’t pronounce the name, I’m very happy to have found it.  Half the fun is in the hunt while identifying them is like cleaning the game.  And stop asking "are they edible?"

Sunday, November 11, 2018

Fuzz on the Kale

Braconid pupae from kale - REK

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.*  
Braconid Wasps - REK
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 Bugguide.net 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 - 2mm   REK
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.

We think of having a virus as a disease but for Braconid wasps polydnaviruses are their nannies.  The wasps carry polydnaviruses which they have coevolved with over thousands of years.  These are injected into a host caterpillar along with their eggs.  The viruses are harmless to the wasp but immediately start to disable the host's immune defenses against the foreign eggs.  The wasp eggs hatch, develop into larvae and feed inside the host until they emerge and form the pupae we found above.  The wasps soon emerge and begin the cycle again with their friendly virus still on board.**

Cabbage white - Bob Moul
These clusters were really good news.  We have lots of cabbage white butterflies (CWB),  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
On close inspections any of you gardeners may find one of these innocent looking caterpillars.  CWB 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  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 them 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.

Note: I am blessed with a wife that will tolerate road kill snakes and a found blue heron skulls 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 and Polydnavirus

Saturday, October 27, 2018

Ghost of Bull Mills

Shed hunting is a popular non-violent winter sport in the Ozarks.  After the fall rut, a buck's need for a bragging rack is gone for the year.  Decreasing testosterone levels lead to reabsorption of the bone at the antler base and eventual shedding, leaving the antlers on the forest floor.  Soon squirrels and wood rats find them and use them for sharpening and shortening their constantly growing incisors and obtaining calcium...unless Barb finds them first.  Barb is the family shed hunter and she found this beautiful pair on January 2008.

This pair ended up on our stone fireplace, tied with leather thongs as the center of the display.  They remained there until the Spirit of the Great Buck returned 10 years later.  Last Tuesday I came into the creek house and found them on the floor with the leather thong neatly sliced in the middle.  Wood rats, aka pack rats, Neotoma floridana, are frequent guests and we hear the click of a trap several times a year so I wasn't concerned and tied them back on the wall.

Here is where it gets a little weird.  Three days later we were eating dinner at 8PM right beside the wall when they came clattering down to the floor.  We hadn't seen or heard any varmit activity and the thong appeared to be cleanly cut.  Spooky!  The next morning I rubbed Siracha jalapeno sauce on the thongs, tied the cut ends together and hung them back up.  I hoped the lip burn of capsicum would dissuade a rat.

The following night at the same time we were eating when they came crashing down again!  Again the cut thong looked clean and no scurrying mammals were in sight.  I went to bed with the image of the Spirit of the Great Buck attacking me at night with an antler.

Gnawed, scissor and knife cut.
The next morning in the cold light of day the fear passed.  Under magnification I compared the cut end of the thong with scissor and knife cuts.  The end was ragged compared to the others, obviously gnawed cleanly in half without the assistance of a ghost.  At least that is what we were telling ourselves.

I hung them again, this time with the thongs tied to copper wire which was looped over the nail.  We returned 18 hours later to find one antler back down on the floor with a chewed thong.  I tied it up again and after sitting on the porch working for an hour I returned to the house and found it cut back down again!  (You can't make stuff like this up!)

This time I put up a game camera on the post opposite the antlers, hoping to catch the culprit digitally.  The next morning the antlers were safe and there was a rat in a trap.  The rat had committed suicide in our rat trap rather than be filmed doing its dastardly deed again.  The antlers have now remained in place after three weeks.

Case closed (we think), but if we don't make the next meeting, who ya gonna call?  Ghost Busters!
And for a pleasant bedtime read to take your mind off that scary tale I would highly recommend this entertaining description of the interaction of termites farming fungus, or is it the fungus that farms the termites?

Wednesday, October 24, 2018

Red-shouldered Bugs

Our Springfield neighbor Cyrus asked me to identify these bugs that were covering his privacy fence.  These are nymphs of the red-shouldered bug (RSB) or jadera bug, Jadera haematoloma.  The interesting question is what are they doing here in our neighborhood?

RSB distribution - soapberrybug.org
RSB are members of the soapberry bug subfamily, Serinethinae.  There are 65 hemiptera species in the family and interest in their their evolution and adaptation to human associated changes on the planet has earned them their own webpage, Soapberry Bugs of the World.   

The sudden spread of these new species is due to adaptive radiation, "the diversification of a group of organisms into forms filling different ecological niches."  Darwin's finches evolving different beaks to adapt to varied food sources are a prime example of adaptive radiation.  For the soapberry bug family, their success is based on their evolving ability to tolerate the cyanide defenses of the soapberry plant.
Bugguide says RSB occur year-round in CA, TX, and FL, with peak numbers in May in central Florida but they are also found in southern Missouri and Kansas. Their native host plants are Sapindaceae family plants and the western soapberry, Sapindus drummondii, is a native species found in a few southern Missouri counties. 

Adults mating - Rebekah D. Wallace
The red-shouldered bug moniker is obvious when you see the adult.  It averages 1/2 inch long.  Most pictures of adults show them mating, either because that is what they do most of the time or that is how to find them holding still for a photograph.  They can be a nuisance like box elder bugs when they invade your home and can also stain children's clothes red when they play in an infested yard.

I think the key to why Cyrus found his fences covered with RSB nymphs lies across the street in a neighbor's goldenrain tree.  This is Koelreuteria paniculata, a native of China and Korea imported to the USA in 1763 and now a popular landscape tree worldwide.  (Editor's confession: we had one once in our back yard.)  In some areas the RSB are observed feeding so often on goldenrain tree seeds, Koelreuteria spp. (Sapindaceae), that they are referred to as goldenrain tree bugs.

Monday, October 22, 2018

Mosquito Bite Update

After posting this blog with photographs of a mosquito biting my arm in the middle of the afternoon, I had it identified on Bugguide as the eastern tree hole mosquito (ETM), Ochlerotatus triseriatusThis turns out to be an unusual insect.

Although it does breed in moist holes in trees, it really specializes in tires, tires stored or trashed on the ground.  If you have ever tried to get all the water out of a tire on a creek cleanup, you know that it is a definition of forever.  This has become an important urban mosquito because of tire dumps and scrap yards around cities where there can be 60,000 mosquitoes per acre in the summer.

Eastern tree hole mosquito - Ilona
Asian tiger mosquito

At first glance to my untrained eye ETM looks a lot like the Asian tiger mosquito.  The differences are more obvious to an entomologist but include the abdomen which is mainly dark scaled with only the margins of the last four segments with pale patches, and legs that lack the white spots of the Asian tiger mosquito.
"Few mosquito species feed rodents. These mammals are just too jittery and quick to sit still for that. But Ochlerotatus triseriatus, even though it bites a wide variety of mammals, including humans and sometimes birds, particularly likes chipmunks and squirrels. These woodland rodents are active during the day when Ochlerotatus triseriatus is seeking hosts in the woods."  Bugguide
We are unlikely to see these during the evening when mosquitoes are abundant.  They tend to occur during the day, as mine was, when their mammal hosts are active.  The ETM transmits La Crosse encephalitis virus, an uncommon but significant disease.  While 70% of females hatching from infected eggs inherit the virus, the good news is that it isn't that common in most of its range.  There are around 72 cases per year in the US and it usually affects children.  If it only would transmit the disease to the wood rats in our house!