"What a thousand acres of Silphiums looked like when they tickled the bellies of the buffalo is a question never again to be answered, and perhaps not even asked." -Aldo Leopold
Belonging to the family of moths called Saturniidae, the Imperial Moth can reach up to six inches. Many members of this family are large-bodied and short-lived as adults – typically living only one or two weeks and not feeding in this stage. This female was attracted to lights during a national moth week event at Cuivre River State Park on July 31, 2016.
I was thrilled when I took my camera inside from shooting in my wildflower garden on a past summer day and identified this hymenopteran as a Bee Wolf. Philanthus gibbosus (Family Crabonidae) is what I am calling this one. Bee Wolves get their name from doing what you expect, feeding primarily on bees. These solitary wasps will load their brood chambers with pretty much any bee or wasp smaller than themselves that they can catch as a provision for a single egg they deposit prior to sealing the chamber shut. Some taxa have specific bees they prefer to catch and this can aid in identification. This poor thing was quite beaten up as you can see in the photograph below. Missing a few legs, it probably escaped a bird or larger insect, and was not happy to have me and my camera in its face. In the photo above I captured it doing a rapid vibration of its wings, something I read that these guys are known for doing as a communication. I can’t imagine what she may have been trying to tell me…
I believe the insect below to also be a species of Bee Wolf, but have not yet been able to put a name with this one. I photographed this one having a drink in a wet area of Shaw Nature Reserve early one morning.
-OZB
The False Milkweed Bug (Lygaeus turcicus) is a seed bug that, although quite similar in appearance to the Small Milkweed Bug (Lygaeus kalmii), is not strongly associated with milkweed.
As can be seen in the photograph above, the False Milkweed Bug is most often found feeding on yellow composites (Family Asteraceae). These bugs were all photographed at Shaw Nature Reserve on what seems to be this insect species’ favorite food plant, the False Sunflower (Heliopsis helianthoides).
There are several members of the Lygaeidae family that are aposematically colored and found in North American prairies. As mentioned, it seems that the False Milkweed Bug does not typically utilize milkweeds. The Small Milkweed Bug feeds on milkweeds as well as other plant taxa. The Large Milkweed Bug feeds exclusively on milkweed. There is obviously a great case of Mullerian mimicry (distasteful organisms appearing similar to one another to benefit from a an easily identified color or body type) going on here, but it gets pretty complicated.
What has happened to the False Milkweed Bug? Is this a case of a species that once fed primarily on milkweed and developed aposematic coloration but has since switched food preference? Or, is this a case of a palatable species mimicking (Batesian mimicry this time) the aposematic coloration of a truly noxious species? Thinking about this, it is easy to see the selective advantages that could result from either possibility.
First, a little background…
Some insects that feed on milkweed benefit by concentrating chemicals called cardiac glycosides that are toxic irritants to vertebrate predators. Cardiac glycosides are an irritant to vertebrate herbivores (livestock) and vertebrates that feed on insects that feed on milkweed and store these compounds in their tissues. However, they are not a significant problem for insects that feed on milkweeds – they simply pass through their guts (insects that store these specific toxins, for example the monarch, must have biochemical changes to avoid toxic effects). The milkweed’s primary defense against the seed bugs and other herbivorous insects is the milky sap that gets forcefully pumped from any mechanical damage that is inflicted on the plant. For this reason the milkweed is a pain for an insect to feed on.
For a seed bug, with its piercing-sucking mouth parts, feeding on the gummy sap of a milkweed is a significant hurdle. Assuming the False Milkweed Bug once fed from milkweed primarily and gave it up would be a significant advantage. Keeping the aposematic coloration, which would allow it to gain the benefit from its vile-tasting, similarly colored cousins, still feeding on milkweed, would be advantageous as well. With my brief observations, the False Milkweed Bug still behaves conspicuously – feeding and doing everything else it does out in the open, suggesting that the aposematic coloration is still working in this mimic-model system, whatever the source history ultimately may be.
-OZB
I’m finally ready to share a few more images from a float down the upper third or so of the Current River that Steve and I had the great fortune to experience this past October. We started at navigable mile 8.0 at Cedar Grove Access and pulled out three days later at mile 51, the confluence of the Current and that other, oh-so desirable, Ozark stream – the Jacks Fork. If one floats slow and quiet, the opportunity to see wildlife is very high in this National Park (Ozark National Scenic Riverways N.P.). I’v shared a couple of images of these guys previously. I believe we found 8-9 Mink during the first day of this float. It was enjoyable watching them busily hunt along the stream banks, mostly oblivious to our presence. As usual, Steve did a great job in keeping us quiet and pointed in the optimal direction for capturing some images.
It was quite a challenge to keep up with these guys as they fished. This one below had caught a nice-sized crayfish and barely slowed to stop and enjoy his snack.
Here is a photo of one investigating the water prior to dipping back in.
Not only does a float down the Current allow for great observations of wildlife, but many geological features are most easily seen by being on the river as well. Cave Spring can now be accessed via a nice newer trail, but it is much nicer accessing it by boat. The endpoint of a vast and interesting karst drainage system, Cave Spring rises from the back of a short cave. At the rear of this cave one can guide a boat over the vertical conduit of the spring, which is ~155 feet deep! What an eerie sensation it is to shine your light down and still see no more than a fraction of the length of the conduit shaft. In the image below, I am on a dry exposed shelf adjacent to the spring’s outlet and Steve is guiding the canoe towards the river.
Pultite is a spring found on this upper stretch of the Current River that is surrounded on all sides except the river by private property. This means that one must boat or wade/swim to visit it. At only ~ 1/10 the output of Big Spring, Pultite is still quite a good-sized spring with and average daily output of ~ 25 million gallons. The effluent channel on this one is quite attractive and I hope to visit more often.
If day one was for the Mink, day two was our River Otter day. We had no Mink, but 5 or 6 of these large weasels were spotted.
Not to forget the birds! These days, a trip to nearly any permanent Missouri water source will likely bring an encounter with a Bald Eagle. Observing these guys in the Ozarks will never get old to me.
Another constant companion on these floats are the Fish Crows, here pictured finishing up a little Ozark lobster.
We were fortunate in having mostly clear and dry skies on this trip, which allowed us to throw our bags directly on whatever gravel bar that struck our fancy and sleep directly underneath the stars. A morning fire was necessary – not only to burn the dew off of our sleeping bags, but of course, for the river-water French-press coffee. Dark skies on these streams afford great opportunities for astrophotography. My only wish for this trip is that I was a little more tolerant of the cold, tiredness and laziness that limited my patience for getting better nightscape images… 😉
I will be posting more images of this trip on my Flickr account in the near future. Thanks for visiting and I hope to post again in the near future.
-OZB
A Thousand Acres of Silphiums 