What Large Skinny Wasp or Fly Has Long Red Antenna, Long Orange Black and Yellow Legs and a Long Wide Red and Black Tail?

Every so often you see an insect that is so colourful it demands your attention even if it’s not particularly pretty. When I saw this one flying around at ankle level, carefully checking for something on every plant and stem, I tried to get a photo. It was moving steadily and never perched while I was watching, so I was pleased to get one photo that is reasonably clear.

It’s One of Our Old Friends, the Ichneumon Wasps

Photo of Ichneumon Wasp Therion Female on NaturalCrooksDotCom

I checked my id with BugGuide.Net and as I suspected this is another type of Ichneumon Wasp. I wrote about seeing a female with an ovipositor so long she could barely fly earlier. This one Is quite different to look at especially with its wide red and black tail.

According to the notes on BugGuide “Ichneumonids are notoriously hard to identify.” Apparently there are a huge number of types and within those there are many that look identical but are actually different ones.

Photo of Therion Ichneumon Wasp near Dames Rocket On NaturalCrooksDotCom
These guys fly so quickly that it’s hard to get them in focus. (OK I admit I’m also not a great photographer.)

This Wasp Has a Very Long Red Abdomen that Widens and is Flattened near the Black “Tail” End

That said, one of the BugGuide experts suggested mine is probably in the Subfamily Anomaloninae, and the genus Therion, and is probably a female.

Photo of Therion Ichneumon Wasp Clover on NaturalCrooksDotCom

There are photos of similar looking ones posted from Pennsylvania and Nova Scotia, among other places in North America.

What Does This Therion Wasp Eat?

Photo of Therion Red Yellow Leg Ichneumon Grape Leaf on NaturalCrooksDotCom

Again, from BugGuide, this family usually preys on butterfly, moth and beetle larvae when it is a larva itself. The female probably lays eggs on or near caterpillars or beetle larvae which then are eaten by her offspring.

So this one I was watching was probably hunting for food for her future larvae.

One butterfly website I visited mentioned that while this may seem cruel to us it is actually a good thing or the numbers of caterpillars would strip bare many trees and plants.

Photo of Ichneumon Wasp Can You See It on NaturalCrooksDotCom
Despite their colouring, these wasps are tricky to spot while they hunt among the clover, vetch and trefoils. Can you spot this one? Do you notice how the tri-coloured dangling legs now look more like stems?

I think I may feel rather smug next spring if I see another of these insects. I wonder how I can casually mention to my friends what it is without it being obvious that I’m trying to brag?

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Have you seen one of these brightly coloured wasps? Please share your sighting with a comment.

11 thoughts on “What Large Skinny Wasp or Fly Has Long Red Antenna, Long Orange Black and Yellow Legs and a Long Wide Red and Black Tail?

  1. I’m glad you know what this ugly thing is! I moved mighty quickly…seems I angered a few wasps while mowing my front lawn today, in Victoria, BC.

  2. HI. I’m in Saskatchewan.
    I found a group of these wasps resting on an old elm tree stump.
    One wasp was inflating a pale yellow sack on what appeared to be the tail. What it going on there? I have some fairly good photos.

    • I’ve read that is something to do with either drilling or laying the egg. You may want to post your photos to a free website called iNaturalist.org
      The volunteers there may be able to confirm the id and provide more info.

  3. I had one just like this visit my 9th floor balcony plants in Toronto today. First time I’d ever seen one; very hard to photograph.

  4. I seen this exact wasp in my yard among clovers two years ago in Seattle. These pics are the only way I could identify it. Thank you.

    • I have never been stung by one and they are common here. Most creatures will bite in self defence but otherwise I doubt that a Therion would be a problem.

    • Interesting! It’s probably a different type than those here in Canada, unless they are circumpolar, which some insects are. Thanks for sharing!

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