Adult leaf beetle - Chrysomela falsa

S.M. Clark: "Chrysomela falsa Brown; I am fairly confident"

… v belov, 2 August, 2010 - 3:57pm

Could you elaborate on the reference -

I find a number of publications with S.M. Clark as one of the authors. I am also very curious to learn how Chrysomela interrupta, knabi, falsa, lapponica, and any others in the immediate group are distinguished. I could find no illustrations of C. falsa whatever, but there are many literature references to it. The other three names all appear very similar to the point of being basically indistinguishable as more than variants of one another, but it is difficult to trust identifications of photos posted on many internet web sites. If it all boils down to distribution, that would be a very weak argument for them being considered different species. It would be interesting to learn more and have the information more readily available. Thanks :0)

… David J. Ferguson, 2 August, 2010 - 4:55pm

sorry, i asked for a name and that what i've got

as i said, i'm no expert, and Riley's bouncing the matter to Clark means to me that the latter must be the only one on the entire planet who could tell.

… v belov, 2 August, 2010 - 5:21pm

I misunderstood (somehow missed one of the comments)

I thought you made the determination based on a published acount by Clark. So, sorry right back at you. It is very perplexing, and it would definitely be fun to learn more. Sometimes I think beetles (especially Lady & Leaf Beetles) are being identified by voodoo, as what look like mere variants (or brothers and sisters) are declared to be different species, but I'm certainly not experienced enough to know either.

… David J. Ferguson, 3 August, 2010 - 12:04am

Was it on Willow or Polpar (Cottonwood)?

It looks like Chrysomela knabi.

I am guessing, but I expect that the only significant difference between out American C. knabi and European C. lapponica is where they are found. I saw C. lapponica all over Cottonwoods (= Black Poplar) in Prague last June, and they look pretty much exactly the same.

… David J. Ferguson, 1 August, 2010 - 5:17pm

While I didn't make note at t

While I didn't make note at the time, we were in a river valley in S-W Alaska that was full of Black Cottonwood (Populus trichocarpa).

… Gavan Watson, 1 August, 2010 - 5:35pm

Maybe there is an Alaskan record now! :0)

Something of a side note; European Black Poplar is Populus nigra. The well-known Lobardy Poplar is a columnar selection of it, but wild trees across Europe are very like Populus deltoides & P. fremontii in characteristics and growth habit.

… David J. Ferguson, 1 August, 2010 - 5:57pm

thanks, Dave and Gavan--

it all makes a lot of sense; i asked Ed Riley, and he said that this is "Chrysomela (Macrolina) sp., lapponica Species Group - S.M. Clark may know species" --so i'll try to refer the matter to Dr. Clark

… v belov, 2 August, 2010 - 12:34pm

After the suggestion of Chrys

After the suggestion of Chrysomela lapponica, I googled the species. I also took photographs of what (I assume) was the beetle larvae, which look very similar to the C. lapponica larvae identified (down to the secretions from the thorax) here.

… Gavan Watson, 2 August, 2010 - 12:46pm

the matter must be left to the experts

the group is very tough, and unless you've messed with them bastards your entire life and know for sure which species may look like this in a specific area, any suggestion based on looks would be nothing but a guess

… v belov, 2 August, 2010 - 12:54pm

knabi seems to have no Alaskan records

… v belov, 1 August, 2010 - 5:19pm

Chrysomela sp.

reminds me of the supercommon & supervariable boreal Eurasian Ch. lapponica -- but i dunno what's its vicariant in NA is

… v belov, 1 August, 2010 - 2:00pm