Large Ichneumon Wasp (Rhyssa persuasoria)

While tidying up the garden I happen to notice a female Large Ichneumon Wasp (Rhyssa persuasoria) hunting for a living host to act as an incubator and food supply for its progeny.
Normally this species of Ichneumon hunts down the Giant Wood Wasp (or Greater Horntail as it's sometimes called) so I'm guessing this Ichneumon has chosen an alternative source either through convenience or because the natural population of the Giant Wood Wasp is in decline? Either way, it was fascinating watching this insect listening out for movement through a few centimeters of solid wood. As you can see from the video it uses its antennae to look for chemical markers that indicate that a suitable host is hidden nearby. It also feels for the vibrations given off by the larvae as it moves within its nesting chamber.
It's been years since I last saw a Giant Wood Wasp and I'm certain there isn't any living in or near the garden so I can postulate that this wasp has adapted its behaviour and found an alternative host type. If anyone knows any different please drop me a line via this site or comments section.
Thanks,
Andrew

Category:

Pets & Animals

Tags:

• Ichneumon wasp
• Rhyssa persuasoria
• Insect
• Wasp
• Leaf-cutter Bee
• Mason Bee
• Insect hotel
• Nature
• Garden
• Natural pest control
• Wildlife in Cambridgeshire
• Swavesey
• Fen Drayton Nature Reserve

[serberusno1]

I thought they laid their eggs just in the wood and their larvae ate the wood. I was chopping wood last year and found a lot of borrowing holes in the blocks which ended in really large fat larvae. I had to use a few such blocks of wood to prop something up in my room and months later, at 3 in the morning an adult one of these wasps emerged from the wood and chased me around the room... My father is a forester and he has told me stories of these wasps trying to lay their eggs in people...

[TK42138]

@serberusno1

They use living hosts such as beetle or bee larvae as incubators and food source. The clever thing is that the wasp larva knows to avoid munching on important nerve groups and organs so as not to kill the host before it emerges otherwise death of host would mean death of wasp. There are some tropical species of predatory wasps and flies that lay their eggs in mammals...

[Hyurachan]

it was creepy finding one in out workshop tonight. my cat found it and we NEVER seen anything like it before. Rather scary looking. o_o

[TK42138]

@Hyurachan

Luckily they're harmless to humans but I'd hate to be a grub on the receiving end of that ovipositor...

[NorthWestVideos]

leaf cutter bees are cool, seen some here in western NY.

Interesting a great footage!

[TK42138]

@NorthWestVideos

Many thanks!

[korndog86]

hey man im from Brockville Ontario we have see 2

[songwriter523]

I have found many of these Rhyssa Persuasoria giant flying insects today. They are going into a log shed. They vary in length some of them being about 5 inches from tip- to tip, whilst smaller ones are half that. Their massively long ovipositor looks like a sting and they are scary-looking. but from your video and from checking out other internet advice sites I'm pretty sure that they are Rhyssa Persuasoria....dozens of them!

[cody3234]

i saw this thing when i was mowing today and i was so curious about it b/c i never saw it before. so i googled it and ended up here. interesting insect.

[NorthWestVideos]

@TK42138 sure!