Large sawfly, Trichiosoma sp.?

[Gerel]

Large, tatty sawfly found today on a young willow. Between 15 - 20 mm long. The closest I can find is Trichiosoma lucorum but the wings don't look quite right, mine seems very dark in comparison to images on the web.



Any thoughts appreciated

Steve

[Geoff F]

Unfortunately this is another of those difficult families about which my knowledge is rather limited (in fact I'm bragging by going as far as 'rather limited')

However, as an alternative, have you considered the closely related Cimbex family? Possibly the Birch Sawfly (Cimbex femoratus) although there are several other Cimbex species.

Apparently, you should be able to separate Trichiosoma and Cimbex by the exposed pale area on the first abdominal segment of Cimbex. There would appear to be something similar in your specimen but I'm definitely not qualified to give an opinion here.

(Help, call an expert, I'm getting out of my depth now!)

[Gerel]

Originally Posted by Geoff F

Unfortunately this is another of those difficult families about which my knowledge is rather limited (in fact I'm bragging by going as far as 'rather limited')

However, as an alternative, have you considered the closely related Cimbex family? Possibly the Birch Sawfly (Cimbex femoratus) although there are several other Cimbex species.

Apparently, you should be able to separate Trichiosoma and Cimbex by the exposed pale area on the first abdominal segment of Cimbex. There would appear to be something similar in your specimen but I'm definitely not qualified to give an opinion here.

(Help, call an expert, I'm getting out of my depth now!)

Hi Geoff,

Personally I could quadruple (at least) my knowledge of sawflies and still have some way to go to get to "fairly limited" . To be honest I don't often attempt them but this one caught my eye due to its size.

I did look at C. femoratus as a possibility (and that would have been quite exciting as it appears that the British Cimbex species are all fairly rare) but apparently that should have yellow "clubs" at the end of the antenna.

I've still got the specimen (I think it was moribund anyway as it hardly moved when I caught it) so I'll check the abdomen and try to get a clearer shot.

BTW when I saw the size of its jaws I was quite glad it wasn't too active, they look vicious.

Steve

[oxycera]

Trichiosoma vitellinae is a possibility.