Sawfly or ichneumon fly - help please

[brianholland]

Watched this wasp or is it a sawfly or an ichneumon for simply ages amazed at its antics. It's long ovipositor seemed to be in two parts and the insect seemed to be feeling with its antennai for soft areas into which to thrust its thinner ovipositor.
It contorted itself bringing the ovipositor tightly under it's body before 'injecting' into the pine log on which it was working.
Can anyone identify it please and maybe add more information .
Thank you,
Brian.

[Rossco]

One of the wood-boring ichneumons seeking to deposit an egg on a wood-dwelling sawfly. Good pic.

[brianholland]

Originally Posted by Rossco

One of the wood-boring ichneumons seeking to deposit an egg on a wood-dwelling sawfly. Good pic.

Wow what a speedy reply so thank you.
Do you happen to know which type of wood boring ichneumon it is as identification would be extremely helpful?.
Thank you for an amazingly quick response - appreciated,
Brian.

[Geoff F]

That narrow wasp like waist makes me think Ichneumon but going any further will require someone with more experience as there are a few thousand from which to choose.

It is probably searching for grubs under the bark and will deposit eggs into them, possibly going directly through the bark.

Rhyssa do operate in a similar manner; but that isn't a positive ID.

[Rossco]

Also, have a look on the web for some of the studies that have been done on these regarding the composition of their cuticle. To chew their way out of wood when they've finished pupating and to penetrate wood to lay eggs, their mandibles and ovipositor are composed of 10% (wet weight) zinc or manganese:

Wiley InterScience :: Session Cookies

[JRsbugs]

Brian, take a look at the Ichneumonidae section here:

Tiere im Garten und Umgebung (Osnabrck)

Janet

[ChrisR]

From the photo we can say that it is a pimpline ichneumon (ie. subfamily Pimplinae) but not much more can be said without a specimen ... oh, other than - it isn't Rhyssa persuasoria Rhyssa has lots of little white dots along the body and the one in the photo doesn't, which puts it in with the others, like Dolichometus and Ephialtes

I really like this group and I find them pretty easy to identify from specimens but they all require microscopic examination even to get to genus ... for species of Dolichometus you need to even look at the pattern of ridges on the tip of the ovipositor!

PS: although most species drill into the wood to attack wood-wasp or wood-boring beetle larvae some species actually just locate holes drilled by other ichneumons and then lay their egg into the Gallery hoping to get the host grub AND the previous ichneumon wasp egg too

[brianholland]

Originally Posted by JRsbugs

Brian, take a look at the Ichneumonidae section here:

Tiere im Garten und Umgebung (Osnabrck)

Janet

Will most certainly do just that. Thank you.
It is my wife that takes the photographs so I claim no credit at all.

Brian.

[brianholland]

Originally Posted by ChrisR

From the photo we can say that it is a pimpline ichneumon (ie. subfamily Pimplinae) but not much more can be said without a specimen ... oh, other than - it isn't Rhyssa persuasoria Rhyssa has lots of little white dots along the body and the one in the photo doesn't, which puts it in with the others, like Dolichometus and Ephialtes

I really like this group and I find them pretty easy to identify from specimens but they all require microscopic examination even to get to genus ... for species of Dolichometus you need to even look at the pattern of ridges on the tip of the ovipositor!

PS: although most species drill into the wood to attack wood-wasp or wood-boring beetle larvae some species actually just locate holes drilled by other ichneumons and then lay their egg into the Gallery hoping to get the host grub AND the previous ichneumon wasp egg too

Chris thank you for such a full and interestinf repky.

As I said my wife who takes the photographs and I were fascinated by these insects and watched them for more than an hour as the contorted themselves impressing us by the way in which they inserted such a delicate and fragile organ into hard timber. Amazing exeprience to watch.
Thank you for your help. I hope shortly to be adding some more images to my wife's flickr site Margaret the Novice.

Brian.