You too may want to curse these flies!
Feb 7, 2021 01:37:09 #
Getting a story through photographs is not something that happens to me very often.
During one outing to the Magic Field, I noticed some movement on the ground. It was a solitary wasp, and she was hard at work digging a burrow. No doubt she would later be provisioning it with paralyzed prey for her larvae. This is Prionyx parkeri, one of the thread-waisted wasps. Her long mandibles indicate that she is a caterpillar hunter, similar to a larger species of thread-waisted wasp (Ammophila procera), which I had shown many weeks ago. I admire the long spurs on her front legs, which were used to good effect as she diligently raked up and carried away sand from her burrow. Removing the sand is one way that they conceal their burrow, since there are various insects that will steal from her if they can.
Thread-waisted wasp drama! by Mark Sturtevant, on Flickr
Thread-waisted wasp drama! by Mark Sturtevant, on Flickr
After a time I saw she had… other watchers (to the right). This was bad news!
The watching Tachinid flies by Mark Sturtevant, on Flickr
The watching Tachinid flies by Mark Sturtevant, on Flickr
These are Tachinid flies. Parasitic. More specifically, these will be kleptoparasites, which means that they intend to lay eggs on her paralyzed prey. Her offspring are not yet born, but they are already doomed. And all her labors will be for nothing.
I watched in fascination. After she cleared out the entrance, she then wandered off. But within a few minutes she returned with a paralyzed caterpillar. It must have been set down just a few feet away while she was opening up her burrow, and therefore her burrow and its separate chambers had already been prepared. She was only unplugging the entrance earlier. Many solitary burrowing wasps do that: They provision a burrow for several young, and they are careful to conceal it when they are away. But they can't understand every form of threat like these Tachinid flies.
She set it down her prize at the entrance, and disappeared inside for what I suppose were final inspections.
The wasp has left prey at the entrance by Mark Sturtevant, on Flickr
Immediately one of the flies made its move. It landed on the caterpillar and inserted an egg into it.
One of the flies lays an egg! by Mark Sturtevant, on Flickr
When she emerged, the flies soon backed away. She moved the caterpillar inside, and after a time re-emerged to then carefully plug the entrance before leaving. The flies continued their watch.
With prey in the burrow, the wasp leaves by Mark Sturtevant, on Flickr
The flies continue to watch by Mark Sturtevant, on Flickr
The remaining flies have good reason to lurk in the area. She will likely be back with new prey.
I do regret not recording these events as a movie with the camera, as that would have ensured that more details were captured. But the microphone would have also recorded a rather continuous stream of profanity from a grown man who was very upset at one of the stories that must unfold every day in the Magic Field.
During one outing to the Magic Field, I noticed some movement on the ground. It was a solitary wasp, and she was hard at work digging a burrow. No doubt she would later be provisioning it with paralyzed prey for her larvae. This is Prionyx parkeri, one of the thread-waisted wasps. Her long mandibles indicate that she is a caterpillar hunter, similar to a larger species of thread-waisted wasp (Ammophila procera), which I had shown many weeks ago. I admire the long spurs on her front legs, which were used to good effect as she diligently raked up and carried away sand from her burrow. Removing the sand is one way that they conceal their burrow, since there are various insects that will steal from her if they can.
Thread-waisted wasp drama! by Mark Sturtevant, on FlickrThread-waisted wasp drama! by Mark Sturtevant, on FlickrAfter a time I saw she had… other watchers (to the right). This was bad news!
The watching Tachinid flies by Mark Sturtevant, on FlickrThe watching Tachinid flies by Mark Sturtevant, on FlickrThese are Tachinid flies. Parasitic. More specifically, these will be kleptoparasites, which means that they intend to lay eggs on her paralyzed prey. Her offspring are not yet born, but they are already doomed. And all her labors will be for nothing.
I watched in fascination. After she cleared out the entrance, she then wandered off. But within a few minutes she returned with a paralyzed caterpillar. It must have been set down just a few feet away while she was opening up her burrow, and therefore her burrow and its separate chambers had already been prepared. She was only unplugging the entrance earlier. Many solitary burrowing wasps do that: They provision a burrow for several young, and they are careful to conceal it when they are away. But they can't understand every form of threat like these Tachinid flies.
She set it down her prize at the entrance, and disappeared inside for what I suppose were final inspections.
The wasp has left prey at the entrance by Mark Sturtevant, on FlickrImmediately one of the flies made its move. It landed on the caterpillar and inserted an egg into it.
One of the flies lays an egg! by Mark Sturtevant, on FlickrWhen she emerged, the flies soon backed away. She moved the caterpillar inside, and after a time re-emerged to then carefully plug the entrance before leaving. The flies continued their watch.
With prey in the burrow, the wasp leaves by Mark Sturtevant, on FlickrThe flies continue to watch by Mark Sturtevant, on FlickrThe remaining flies have good reason to lurk in the area. She will likely be back with new prey.
I do regret not recording these events as a movie with the camera, as that would have ensured that more details were captured. But the microphone would have also recorded a rather continuous stream of profanity from a grown man who was very upset at one of the stories that must unfold every day in the Magic Field.
Feb 7, 2021 05:40:16 #
Feb 7, 2021 05:58:43 #
Feb 7, 2021 11:02:42 #
Wow, that was a wonderful story in pictures and good photography too.
Feb 7, 2021 11:16:01 #
Feb 7, 2021 11:29:18 #
Feb 7, 2021 16:02:36 #
Feb 8, 2021 07:43:03 #
Feb 8, 2021 10:49:16 #
Nice story and commentary. Some great captures. Fascinating!
Feb 8, 2021 11:20:25 #
Feb 8, 2021 12:12:46 #
Feb 8, 2021 13:12:31 #
Feb 8, 2021 16:36:32 #
Feb 8, 2021 17:16:50 #
Mark Sturtevant wrote:
Beautiful work, Mark.Thank you, everybody!
For those of us who understand or live close to this world, this is outstanding documentation. This is the magic of nature in real time.
As a Monarch Waystation, Tachinid flies are a nemesis of mine.
Feb 8, 2021 17:52:32 #
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