Tag: Bill Duncan

The Golden-legged Mydas (Mydas tibialis)

macro, wildlife, wildlife photography

This past August while visiting the Weldon Spring Site Interpretive Center in St. Charles, County MO, I stumbled upon one of my favorites that I have not seen since taking entomology at the University close to 20 years ago. When first encountering this insect you immediately think it must be one of the spider wasps or perhaps the great black wasp (Sphex pensylvanicus). For those who don’t immediately flee the area and instead look a little closer, you will see this is actually a very special species of fly.

Mydas tibialis, the golden-legged mydas nectaring from one of its favorite food sources, the blossom of Eryngium yuccifolium (rattlesnake master).

Mydas tibialis (golden-legged mydas) are Batesian mimics, meaning they are harmless mimics of a potentially harmful species, such as wasps. The adult form of mydas flies are purportedly short-lived. They spend the most of their lives underground where they feed on grubs in the soil.

In order to truly appreciate the size of a mydas fly, one must see them in person. If you are familiar with the size of a typical rattlesnake master inflorescence, then you might be able to appreciate this from these photos.

After doing a short bit of research, there doesn’t seem to be nearly enough known about the life history of our mydas flies. This is a shame. Not only are they fascinating animals with much waiting to be discovered but it also looks like they can be good biocontrol agents. Hopefully it won’t be another 20 years before I find one again.

Mydas tibialis, the golden giant of the Dipterans.

Agapostemon – The Stamen Lovers

macro, wildlife, wildlife photography

Photographed in April, this Agapostemon (either sericeus or splendens) bee is seen visiting blooms of Claytonia virginica (spring beauty). Agapostemon comes from two Greek words – agapetos, meaning beloved, and stemon, for stamen – these referring to their obvious fondness and attraction to flowers, particularly those in the Asteraceae. We can tell this bee is female because males of this genus have yellow and black striped abdomens.

An Agapostemon sp. female nectaring from a Claytonia virginica bloom, April 2021, St. Louis County, MO

Magnolia tripetala (Umbrella Magnolia)

native plants

It was a pleasure seeing my first wild Magnolia tripetala on our trip to Arkansas back in May 2021. To make things even better, this plant was found within a hundred feet or so from the Kentucky lady’s slippers we were there to photograph.

Magnolia tripetala (umbrella magnolia) photographed within the Ouachita National Forest.

Zombie Spider Bastards!

macro, wildlife, wildlife photography

A little late for a Halloween post, my apologies, but I wanted to share what is probably the best-preserved example of a Gibellula-infected spider I have found to date. Gibellula is a genus of endoparasitic Cordyceps fungi that primarily infect spiders. Although the nicely preserved jumping spider (Salticidae) and the fruiting branches of the fungus is what grabs the eye, it wasn’t until I finished processing the photos that a question came to mind for me.

See the white fibers that surround the spider? I see two possible options for the origin of these. First, I should explain a little of what I have read about the life history of these parasitic fungi. Similar to the Cordyceps that infect insects, Gibellula-infected spiders become “zombies” and will typically position themselves on the undersides of leaves, as the one pictured here was found. Here the fungus finally kills its host and sends out spores that are now nicely positioned to fall upon potential new spider hosts. Back to that bed of white threads. I see one function and two possible origin ideas of these. I believe the function of these is to keep the spider anchored to the leaf so that it does not fall to the ground and greatly hinder the ability of the fungi to infect new hosts. For the potential origin, these could be mycelia of the infecting fungus, or, even better, these could be silk created by the spider, induced by the fungus to anchor itself as the last act before its death.

If you have other ideas as to the potential origin or function of this bead of threads, please let me know!

A jumping spider infected by Gibellula fungus.

So Long to the Chimney Swifts

birds, wildlife, wildlife photography

Our neighborhood Chimney Swifts have pretty much headed south and will be missed until they come again in the spring. This reminds me of a some birds that Casey and I ran into at a location we camped at in Arkansas this spring. They were using a secluded and dark hallway that lead to bathrooms we used for their overnight roosting. This was the first time I have been so close to perched Chimney Swifts so I had to take a few pics.

Chimney Swift (Chaetura pelagica)

Thalia dealbata (Powdery Thalia)

native plants

Thalia dealbata, or powdery thalia, is a fascinating plant that I was introduced to this past August while on a botany trip with Pete Kozich and Stephen Dilks. A member of the mostly tropical arrowroot family (Marantaceae), T. dealbata is the only member of this family to be found in Missouri and only in the low and wet areas of the southeastern portion of the state. We found these plants a little late in their flowering season but with a few blooms in prime condition remaining at Otter Slough Conservation Area.

A closeup look at the mirrored pair of flowers of Thalia dealbata (powdery thalia).

The leaves of Thalia are what the plants are primarily known for, looking very reminiscent of the cannas and very tropical in appearance. However, doing a little research after seeing these guys for the first time, I have become fascinated with the flowers and the pollination mechanism they developed. First of all, what appears to be a single flower in the image posted here is actually a pair of blooms in mirror image of each other. Additionally, the gorgeous purple petals are not petals at all but highly modified and sterile stamens (staminodes). This is just the beginning of the weird story of these flowers. These staminodes are key to a pollination strategy that literally throws pollen in the face of and often ends in the demise of all but the strongest of would-be insect pollinators. I was going to attempt to try and describe the pollination biology of this system, but this has been expertly described by Price and Rogers in a 1987 article published in Missouriensis. I highly recommend you give this a read!

Pete standing behind a nice batch of Thalia dealbata.

Agalinis fasciculata (Fasciculate False Foxglove)

native plants

Agalinis fasciculata, known as the fasciculate false foxglove and beach false foxglove was one of the more fascinating and unexpected plants I became acquainted with this year. A member of the Orobanchaceae family, this species is an annual hemiparasitic plant that does well in poor and sandy soils. I photographed these plants at the Missouri Mines State Historic Site in St. Francois County.

The genus Agalinis comes from the Greek – agan, meaning ‘very’ and linon, refering to ‘flax’, apparently in reference to the similarity of the flowers to those of flax. The species and common names refer to the fasciculate, or bundled manner in which the leaves are attached to the stem – something I failed to take any photos of this year. In my defense, much of the stem and leaves of these plants in mid-September were beginning to senesce and were not very photogenic.

Agalinis fasciculata (Fasciculate False Foxglove) in glorious bloom at Missouri Mines State Historic Site.
Many species of bees and flies like this syrphid fly act as pollinators of Agalinis fasciculata.
A rare six-lobed corolla of Agalinis fasciculata. This was the only six-lobed flower I found among hundreds I observed on this visit.

Aesculus pavia (Red Buckeye)

native plants

The red buckeye (Aesculus pavia) was definitely one of the plants of the year for me. With so many trips to southeastern Missouri (this buckeye is primarily natively found in the Mississippi Lowlands Division of Missouri) and Arkansas, I and my friends came across this plant in bloom many times. This particular little stand was found at Arkansas Oak Natural Area in Nevada County, AR. The etymology of the Latin name: Aesculus refers to the horsechestnut and pavia is named for Peter Paaw, an early 17th century Dutch botanist. This plant can be grown at least as far north as the St. Louis area but apparently needs high quality rich soil to thrive.

A stand of red buckeye (Aesculus pavia) growing in a pine forest-savannah setting at Arkansas Oak Natural Area.