Beetle IDs

[Tiggrx]

Could anyone help ID these two beetles.

I think these are some sort of Donacia. They were on yellow iris flowers at the edge of a large pond in Somerset. Having looked at a few distribution maps D. marginata & D. simplex are both recorded for this area. However I wonder if it could be D. thalassina (recorded from not too far away)




The second one appeared in large quantities (>100) on wet paving slabs in a Somerset garden. The slabs were wet from a sprinkler system and the beetles seemed to appear quite quickly from nowhere. They seemed a bit helpless when in water so I originally thought it was a terrestrial beetle which had been washed out of the soil in the adjacent flowerbeds. However the closest I can find is the water beetle Heliophorus aquaticus . It was about 5-6mm long.





Thanks for any help
Aaron

[Jenny W]

The first beetle could also be a Plateumaris. There is no way of telling which species from the photo, it would require microscopic (or at least hand lens) examination.

[Tiggrx]

Originally Posted by Jenny W

The first beetle could also be a Plateumaris. There is no way of telling which species from the photo, it would require microscopic (or at least hand lens) examination.

Thought that may be the case. I did also wonder about Plateumaris...

[Dogghound]

The first beetle is most likely Plateumaris sericea a species heavily associated with yellow flag.

[Tiggrx]

Originally Posted by Dogghound

The first beetle is most likely Plateumaris sericea a species heavily associated with yellow flag.

Thanks, I shall label the pics as that with a '?'

[JonSadler]

The other beetles are species of Helophorus. You need to look at their bits to identify them to species level.

Regards
Jon