waitingfortheweek: Interesting gall on a Canadian…
Interesting gall on a Canadian thistle
This reminds me of the galls produced in Coyote Brush (Baccharis pilularis) by a small moth, Gnorimoschema baccharisella. Some googling suggests yours might actually be Urophora cardui, however, a type of gall-inducing fruit fly that has been imported from Europe in an effort to control the invasive thistle.
Thanks for sharing the image! The Tumblr gall fandom: small but doughty.
Reposted from http://ift.tt/2bnJOnq.
Tags: insects, galls, without any actually visible insects, so this is probably safe for Sally-viewing, Urophora cardui.