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Poplar Petiolegall Aphid (Pemphigus populitransversus)
Photo#346728
Copyright © 2009
MJ Hatfield
Pemphigus populitransversus, gall on cottonwood -
Pemphigus populitransversus
Plymouth Rock, Winneshiek County, Iowa, USA
October 18, 2009
Collected 11-Oct-2009
Contributed by
MJ Hatfield
on 26 October, 2009 - 7:21am
Last updated 26 November, 2009 - 1:24pm
Moved
Moved from
Pemphigus populicaulis
. Now
this
one I'd be comfortable calling
Pemphigus populitransversus
: an oval gall with a transverse slit, not touching the leaf blade, and on an aspen leaf.
P. populicaulis
galls are more irregularly shaped, have an oblique opening, and are at the base of cottonwood leaf blades. I wonder if the one in your other image could be an atypically placed
P. populitransversus
gall?
…
Charley Eiseman
, 26 October, 2009 - 8:54am
Except..
I showed this to John Pearson, botanist, and it is a cottonwood leaf not an aspen. Does that change things?
…
MJ Hatfield
, 30 October, 2009 - 8:21pm
I don't think so.
Whereas
Pemphigus populicaulis
apparently is only found on cottonwoods, Felt doesn't specify a host for
Pemphigus populitransversus
beyond the genus
Populus
, which includes both cottonwoods and aspens. I've never found this species on a cottonwood leaf, but this gall looks just like the ones I've found on aspen leaves.
…
Charley Eiseman
, 30 October, 2009 - 8:25pm
uh oh
It looks as if I have 2 different Pemphigus galls in the same container, so there is no way to know which gall the aphids that emerged are associated with. Perhaps since the galls are both Pemphigus I can move the insects to family level and leave the galls separate. What say you?
…
MJ Hatfield
, 26 October, 2009 - 9:27am
Yes
I'd unlink the aphids from the gall and move them to genus level, with thumbnails linking to both of the galls that were in the container.
…
Charley Eiseman
, 26 October, 2009 - 9:30am