One of my favorite mythological tales is that of King Midas, the ruler of Phrygia who wished for and was granted the power to turn everything he touched into gold. Apparently, this was his undoing as he starved to death when the food he touched turned into inedible gold - poor guy. Last week my nature- loving neighbor shared a wonderful video of majestic mydas flies cavorting around the stump of an ancient pin oak tree that once graced her yard. It seems this stump serves as a perennial home for her mydas flies. Each summer they provide entertaining performances as males battle each other and find romance with the females which, in turn, search for places to deposit their spawn in just the right spot in the decaying stump. Female mydas flies deposit eggs in rotting wood where their predaceous larvae dine on other soft bodied insects, including the grubs of scarab beetles, kin of the ones we met in previous episodes such as “Hercules Beetles.”

The star of this episode, Mydas clavatus, the clubbed mydas fly, named for its clubbed antennae, is a member of a relatively small family of very large flies whose biology remains somewhat unknown. Mydas clavatus is among the largest of all North American flies, with a body length often more than an inch. It is believed that their black–velvet coloration presents the visage of a large stinging wasp. This confers protection from enlightened predators that have learned not to mess with painful, black, stinging insects. One report holds that they also have a behavioral mimicry in which they curl their abdomen and jab at an aggressor in a mock stinging charade aimed to fool potential predators.

Adult flies have been observed dining on the nectar and pollen of flowers of Spiraea alba, Pycnanthemum virginianum, Asclepias syriaca, A. verticillata, Monarda punctata, Teucrium canadense, Verbena hastata and Saponana officinali. In years past, they frequented by garden, attracted perhaps by the abundance of butterfly weed in my flower bed which served as a beacon for this unusual visitor.

Adult mydas flies are rather tranquil and allow bug geeks to take pictures before flying away for some unknown fly business. Unfortunately for me, the mydas fly that have visited my garden for photo ops lacked the Midas touch and the holly and pumpkin on which it perched failed to turn to gold. Still, seeing these unusual creatures always provides a golden moment for a bug geek.

References

Bug of the Week thanks Pam Gealey for sharing videos and images of her majestic mydas flies that inspired with episode. Dr. Shrewsbury captured images of the mydas fly. The delightful account “Adult female Mydas clavatus (Diptera: Mydidae) feeding on flowers in Wisconsin” by Andrew H. Williams and the interesting web page “Mydas fly” by Jeffrey K. Barnes were used as references.