unknown Hymenoptera - Dolerus nitens

Moved

… v belov, 14 April, 2012 - 5:52pm

Tenthredinidae, Dolerinae

Dolerus nitens Zaddach. There are other black Dolerus, but the early flight period, size, and being covered with pollen narrows it down to the introduced D. nitens.

… Dave Smith, 13 April, 2012 - 7:19pm

Non-native

I didn't know that! It figures: most native insects don't visit the non-native forsythia flowers.
I am adding it to my list of non-natiaaves. Thanks. Are there any non-native relatives of this species?

… Beatriz Moisset, 13 April, 2012 - 7:28pm

lots of native insects visit Forsythia

Mine is full of all the pollinators currently flying: Andrena rugosa, a Vespidae, at least four Diptera including Bombylius major, and probably others I haven't spotted yet. But the Dolerus is the only one that the Forsythia pollen sticks to so hard it can't dislodge it, all the others can clean it off normally.

… John Sankey, 14 April, 2012 - 6:33am

Very interesting

Sonya has also seen many insects on forsythia plants (not necessarily on flowers). My experience is just the opposite. Years ago I stopped looking for pollinators on non-native flowers because it was mostly a waste of time. Other studies have noticed that pollinators are more likely to go to native flowers than non-native. The difference is huge.
This spring I have been inspecting the flowers of forsythia, lesser celandines and daffodils, to test this idea. I spent several hours on each of those species, although I didn't attempt to collect statistical data. I did it on warm sunny days, just the right time for flower visitors and, once again, saw scarcely any insects, just some beetles or bugs who don't seem to be pollinators.
I will take another look before the flowers wilt.

… Beatriz Moisset, 14 April, 2012 - 9:55am

This is the only

introduced species of Dolerus that I a aware of.

… Dave Smith, 13 April, 2012 - 7:52pm

Dolerus sp.

… v belov, 13 April, 2012 - 5:42pm

Pollen

It is nice to see an image of the pollen covered specimen. But it would be nice to remove the pollen with a thin brush, if possible, so details are more obvious.
It looks like a sawfly. I am sure that somebody will be able to tell you more.

… Beatriz Moisset, 13 April, 2012 - 5:33pm

tried to remove pollen

Beatriz, the pollen is so gooey and so stuck on that I haven't been able to remove more than a tiny bit of it, even with the brush loaded with alcohol or acetone.

… John Sankey, 13 April, 2012 - 6:47pm

Aha!

I bet that the sawfly wasn't happy about it either.

… Beatriz Moisset, 13 April, 2012 - 7:01pm

here's one even worse off!

http://www.flickr.com/photos/mehampson/4500120164/

… John Sankey, 13 April, 2012 - 7:15pm