Hickory Midge Galls

I just stepped out to grab a couple of oak leaves to feed some sawfly larvae that I’m accidentally raising, and on the way I peeked under a hickory branch that was jutting out over the road, and discovered a nice assortment of galls on the undersides of the leaves. Just like hackberry, hickory is the host to a midge genus whose species produce detachable leaf galls with a wide variety of shapes.  There are 56 known Caryomyia species, most of which Raymond J. Gagné described for the first time in 2008, in a paper that he was kind enough to send me a few years ago*.

Hickory peach-haired galls (Caryomyia persicoides (Osten Sacken)).

Hickory placenta gall (Caryomyia thompsoni Felt).

There are a few species with densely hairy galls like this, but I’m guessing these are Caryomyia purpurea Gagné, the hickory purple gumdrop galls. If so, the larval cell on the inside has a deep purple lining.

Hickory marginate gall (Caryomyia marginata Gagné), with another hickory placenta gall.

Hickory bullet galls (Caryomyia tubicola Osten Sacken).

I can’t find a match for these translucent, bumpy ones, which are next to a developing hickory marginate gall. They are sticky, and most closely resemble hickory sticky globe galls (Caryomyia caryae Osten Sacken), but those should be opaque and green, later turning brown.

Hickory shmoo gall (Caryomyia shmoo Gagné).

I’ve wanted to find this last one ever since I came across it in the paper.  Its namesake:

For even more hickory midge galls, see BugGuide.

* Gagné, Raymond J. 2008. The Gall Midges (Diptera: Cecidomyiidae) of Hickories (Juglandaceae: Carya). Memoirs of the American Entomological Society 48:1-147.