Published September 10, 2022 Uncategorized2 Comments
Gall Week 2022 ends tomorrow, so I looked around this past week to see what I could see. The fallen leaves of a Mockernut (Carya tomentosa) in Green-Wood proved particularly fruitful. With oaks, the main gall-inducers are tiny wasps. For hickories, it’s Caryomyia genus flies and Phylloxera genus aphids. This one seems to be Caryomyia cynipsea. When I put this up on iNaturalist, this was the third observation of this species (anywhere)Here’s another new species, at least for me: Caryomyia eumaris. This is the first New York state observation on iNaturalist.
Galls are created when the inducer’s chemistry re-engineers the plant’s chemistry. The gall itself is abnormal plant growth, which can occur on the leaf, stem/branch, flower, fruit, etc, depending on the species of inducer involved. Inducer larvae grow up inside the gall, which provides protection (at least some protection; there are plenty of parasitic wasps happy to look for a home like this) and food.
Thank you for sharing your gall photos and expertise. Your photo in the past years ago helped me identify a gall on a bush I had. I started reading your posts since then and have enjoyed them. Thanks for posting your descriptive observations.
Backyard and Beyond 
Thank you for sharing your gall photos and expertise. Your photo in the past years ago helped me identify a gall on a bush I had. I started reading your posts since then and have enjoyed them. Thanks for posting your descriptive observations.
Glad I could help!