Tuesday, August 30, 2016
While a flower-filled field may look peaceful, in reality scores of wee killers lurk among the blooms. A flower can be a very dangerous place for a nectar-seeking pollinating insect. I did a pretty intensive field trip through several southeastern Ohio counties last weekend, and managed to find a number of specimens of one of my favorite killers in the flowers, the Jagged Ambush Bugs in the genus Phymata.
The genus Phymata is not especially large in North America north of Mexico - 20 species or so - and diversity thins out even more east of the Mississippi. Apparently nearly all of the ones in Ohio and vicinity fall into three species: Phymata americana, P. fasciata, and P. pennsylvanica. Separating these species can be quite difficult, especially from photos, so I'm just leaving it at that.
The kill shown here is a great irony; karmic payback? Tachinid flies are parasitoids, laying eggs on hosts such as caterpillars and katydids. The fly egg hatches a tiny grub which quickly bores into the host and commences eating it alive. The fly maggot feeds and grows within its victim, ultimately killing it. This tachinid has met its match in this ferocious little ambush bug.
Keep an eye on the flowers this fall, and I'll guarantee you'll spot a Jagged Ambush Bug sooner or later.
Friday, August 26, 2016
It was a great time, and I got to see and spend time with some wonderful people that I don't see nearly enough of. After my talk concluded, a bunch of us went outside for a stroll around the property to see what we could see. We didn't make it far. Basically, a nearly two hour loop that started at the sign in the photo, and ended there. We only made a big circle around the building, despite starting with more grandiose intentions!
But the walk's shortness was dictated by all the critters we saw in just that brief distance. I'll share some of them below.
About 14,000 visitors annually come to learn about nature here, and a great many of them are school-aged. The site is worth its weight in gold for natural history education. The number of visitors just keeps increasing, demonstrating the value - need! - for places such as this, where people can get away from the hustle-bustle and into a tranquil biodiversity-filled place.
Consider visiting, and especially if you live in the central Ohio region, becoming a supporter. Read all about Stratford Ecological Center RIGHT HERE.
As soon as we gathered to head off, this handsome Potter Wasp, Monobia quadridens, flew in to entertain us as it nectared on a flower-potted Sedum. Its appearance was apropos, as I had just lectured on caterpillars and their role in the big-picture food web. Potter Wasps prey on caterpillars.
NOTE: While I usually do macro work with a full-frame Canon 5DS-R, the image above and those that follow were created with the crop-sensor Canon 7D II. It is a highly competent camera for macro, and about any other kind of shooting. The lens was the 100mm f/2.8L macro, and illumination was via the Canon 600 speedlite muffled by a Lumiquest softbox.
"Mr. McCormac" he whispered, "there's a problem with the salad. Worms are in the kale! It's taking us a while to pick them out." "Worms!" said I - "let me see these 'worms'"! Sure enough, Cross-striped Cabbageworms were in the kale and doing their best to eat it all before we had a crack at the green stuff. The photo above is of two of those very caterpillars.
Well, this was a wonderful opportunity and we brought out some of the salad-eating caterpillars for the group to admire. Everyone was pleased to see these handsome larvae and many photos were made. After the salad-stealing caterpillars had been removed from the greenery, the salads were consumed with no qualms or grumbling by anyone.
I think that our caterpillar conference attendees were probably the only group on earth that would have reacted favorably to this insect intrusion. And I'm sure the chef was pleased that we weren't upset, and probably also thought us to be weirdos of the highest order.
Tuesday, August 23, 2016
A friendly public service announcement on behalf of America's flower flies (family Syrphidae). Those little bee-like insects (such as in the photo) that sometimes land on you are not bees. They are valuable, pollinating flies that do a good job of mimicking bees. While they do have a tendency to land on people's skin - seeking minerals in your sweat - they cannot sting, bite or otherwise hurt you. Pancaking them, or dousing one's self with insect repellent is not necessary. I only say this because I've seen about six people in the last week overreacting to the "aggressive bees".
Apparently it was of help to the flies, as the message got a lot of attention. This experience got me to thinking about the broader picture of mimicry, one of my favorite subjects in all of natural history. The flower fly (or hover fly) does a darn good job at looking like something that might sting, thus theoretically dissuading would be predators from attacking. But flower flies are just the tip of the iceberg when it comes to insects mimicking the appearance of Hymenoptera (bees and wasps) that pack a punch.
A few examples follow...
Why look like a bumblebee? Possible because robberflies are prone to perching out in the open, and looking like something that stings may telegraph a message of AVOID to birds.
Sometime I'll have to write about all the creatures that mimic bird droppings.
Sunday, August 21, 2016
NOTE: Sometimes people ask me why I pick certain headlines for my columns. The answer: I don't. Editors craft newspaper headlines, not the reporters and writers.
One of Ohio’s stranger natural-history events had its origins in a ditch in Adams County. In July 2012, John Howard, Dave Wagner and I were in said ditch, marveling at some extraordinary moth. (I’ve forgotten the species.)
Howard is a technician for General Electric and naturalist extraordinaire. Wagner is a professor at the University of Connecticut and author of the "Caterpillars of Eastern North America" (Princeton, $29.95). We had been conducting field work in this Ohio River county.
When we found the moth, it triggered a discussion about the fabulous diversity of these winged creatures. If we could expose more people to the wonders of moths, we reasoned, more people would become enamored with natural history.
Mothapalooza was born.
A call to Mary Ann Barnett, a natural-history enthusiast and organizer extraordinaire, bore fruit. She was instrumental in shaping the conference.
By early 2013, our moth-centric conference was ready and slated for a June weekend. We hoped to attract perhaps 30 to 40 diehards. In all, about 150 attended the inaugural event, far exceeding expectations.
That first conference was based at the Lodge at Shawnee State Park, smack in the midst of biodiversity-rich Scioto and Adams counties. The following year we moved to Burr Oak State Park in Morgan County, and the third and fourth conferences have been back at Shawnee.
The most recent Mothapalooza took place the first weekend of August, with another full house. Some of the region’s premier moth experts shared their knowledge with participants, and generous sponsors, in particular the Ohio Department of Natural Resources' Division of Wildlife, provide critical support.
Although Mothapalooza features wonderful speakers, vendors, artists and others, field trips to see moths are the core of the conference. Nocturnal excursions on Friday and Saturday nights departed at 9:45 pm, and some attendees didn't return to the lodge until 3:00 am. We have to keep moths’ hours.
Moth stations are situated in the wild lands of Shawnee State Forest and adjacent Edge of Appalachia Preserve. A station consists of hung sheets illuminated by specialized lights. They’re irresistible to moths, which fly to the sheets for easy observation.
Perhaps 1,500 moth species occur in this region, and their diversity is dazzling. Species range from bat-sized imperial moths to micro moths scarcely visible to the unaided eye. The collective cast is painted in a rainbow of other colors.
Two major factors have spiked interest in moths. In 2012, the "Peterson Field Guide to Moths of Northeastern North America" was released, exposing a huge new audience to the magic of moths.
The meteoric growth and increased accessibility of digital cameras is the other factor. Moths are fabulous subjects, and relatively easy to photograph. Many images from Mothapalooza 2016 can be found at my blog.
For more information, visit www.mothapalooza.org.
Naturalist Jim McCormac writes a column for The Dispatch on the first, third and fifth Sundays of the month. He also writes about nature at www.jimmccormac.blogspot.com .
Thursday, August 18, 2016
Monday, August 15, 2016
The venue was the U.S. Army Corps of Engineers' fabulous visitor center at Caesar Creek Lake in Warren County. We really like holding events at this place, as the conference room is perfect for groups of up to 175 or so people, AND one only need step outside the doors to get into interesting habitat. As proof, one of our field trip leaders, John Howard (striped shirt, back to camera) shows a group a huge female Dobsonfly on the wall by the doors. There was also a stunning Cloudless Sulphur butterfly in the raised flower bed, near that rock.
NOTE: The Saddleback in this photo is a proxy for the actual specimen that we found. I imaged the animal above two years ago in southern Ohio. Scroll on and you'll see why I used a substitute image to show what one of these cats looks like.
Braconid wasps and tachinid flies, among others, are parasitoids. Parasitoid insects such as these generally kill their hosts. One of these flies or wasps lays its eggs on - or injects them into - the victim. The eggs hatch quickly, and the tiny grub begins boring its way through the host's body, consuming non-vital tissues at first. Obviously, as evidenced by the photo above, many such larvae might occupy a host. The parasitoids cleverly avoid consuming the organs that allow the caterpillar to continue to remain mobile and thus better elude other predators, such as birds. Finally, in a grisly last hurrah, the larvae finish off the victim and burst from the dead husk and spin tiny cylindric cocoons.
I had the vial in my office, and when I checked it around 10 am, a few wasps were flying about within. An inspection of the cocoons revealed that most appeared ready to hatch, but in spite of regular monitoring, no more emerged during the day.
It doesn't take long for one to pop out. As the pupa matures into an adult wasp, the outer edges of the summit (lid) of the cocoon get thinner and more fragile. The wasp then apparently chews a very neat incision around the summit of the cocoon, and when the time is right, it pushes up and pops the lid off. From the time that I could detect an obvious movement of the lid in the case of the wasp above, it was probably only 30-45 seconds before it had broken completely free of the cocoon. The three cocoons to the right of the wasp still have their occupants. Other cocoons have the lids popped and we can see the almost perfectly circular shape of the lid.
Making images of these insects was not easy. The wasps are probably only 2-3 millimeters in length - smaller than can be effectively dealt with by using a "normal" macro lens such as my Canon 100 mm. Thus, I resorted to the tricky but useful Canon MP-E 65mm "mega" macro lens, which magnifies up to 5x life size. But this lens is not forgiving, and very hard to use on objects that are moving. It has no focusing system; the operator just moves the camera back and forth to focus. Depth of field is extremely shallow, even at f/16 (what these images were made at), and front of the lens flash is essential. And it is nearly essential that the camera be firmly braced in some way.
But if all goes passingly well, we can see into a micro world that is far too small to be visible to the unaided eye.
The wasp family Braconidae is immense, and undoubtedly includes scores of species as yet undescribed. I have no idea what species these wasps are, or even the genus. Identification of species in this group is the bailiwick of specialized experts, and I suspect specific identification isn't even possible in most cases without a specimen in hand. If anyone reading this can shed more light regarding identification, please let me know.
A fate such as documented above is very common in the caterpillar world. Those of us who regularly hunt for caterpillars are quite used to seeing victims bristling with wasp cocoons, and/or the shells of empty tachinid fly eggs stuck to their exteriors.
Very little in Nature is Disneyesque.
Sunday, August 14, 2016
Mark your calendars for Saturday, August 27. That's the date of the 5th annual Ohio Sustainable Landscapes Symposium, hosted by Dawes Arboretum. The sprawling arboretum, located near Newark in Licking County, is a beautiful place to visit at any season and is the venue for the symposium.
Keynote speaker is John Watts, resource manager for Franklin County Metro Parks. John has been a driving force behind much of the park district's large-scale wetland and prairie restoration. Following the speakers, field trips will visit various habitats within the arboretum. It's sure to be an interesting and educational event.
For complete details and registration information, GO HERE.