A small, striking Leaf Gall, looking like a fried egg or a bullseye! These occurred on the upper surface of the leaves and if you look closely, you can see the small white larva in the center of the red circle. These Galls are called Maple Eyes and are produced by the larva of a Gall Midge, Family Cecidomyiidae. The pigmentation of these galls is amazing and I'm curious whether the colors are produced by the insect or come from the plant. According to this article, the larva induces the leaf to develop striking concentric rings of yellow (carotenoids) and red (anthocyanins) pigments which leaves normally use to create the yellows and reds of autumn. (http://bugoftheweek.com/blog/2013/1/23/m...).
Mendenhall Glacier National Park, Juneau Alaska.
To see an example of a Gall Midge adult fly see: http://www.projectnoah.org/spottings/811....
Lat: 58.36, Long: -134.38
Spotted on Sep 4, 2018
Submitted on Sep 29, 2018
and 1 other person favorited this spotting