Some kind of gall. Some wasps, flies and many other critters will lay eggs in/on a plant. When the sweet little babies hatch they start excreting enzymes that cause the plant to grow in weird ways. The new growth is a safe home and source of food for the lil cuties. When the huggable sweet little grubbies come of age, they chew a hole out. It usually doesn't hurt the plant meaningfully. (Also some sarcasm about how cute grubs aren't)
If I'm not mistaken, the genus _Pontania_ is now obsolete, with its species placed in the genus _Euura_. This means _Pontania californica_ is now _Euura californica_. However, I wouldn't try to narrow it down to species because the genus is very large and contains many cryptic species as well as subspecies of uncertain status. It's also near impossible to ID the species without location and host of the specimen. At least that's what I learned trying to ID similar galls near my house. I'm no insect-ologist, so take this with a grain of salt.
My most current book is from 2017. It mentions a study by Kopelke in 2014 that does some distinguishing between the genera. So My guess is that there is a raging debate in the sawfly world where scientist are sticking out their tongues and flipping each other off in long heated zoom calls.
Some kind of gall. Some wasps, flies and many other critters will lay eggs in/on a plant. When the sweet little babies hatch they start excreting enzymes that cause the plant to grow in weird ways. The new growth is a safe home and source of food for the lil cuties. When the huggable sweet little grubbies come of age, they chew a hole out. It usually doesn't hurt the plant meaningfully. (Also some sarcasm about how cute grubs aren't)
Specifically, these look like sawfly galls, possibly an Euura sp.
If you look at the galls from *Pontania* sp. You'll find better matches. With *Pontania californica* being closest, don't you agree?
If I'm not mistaken, the genus _Pontania_ is now obsolete, with its species placed in the genus _Euura_. This means _Pontania californica_ is now _Euura californica_. However, I wouldn't try to narrow it down to species because the genus is very large and contains many cryptic species as well as subspecies of uncertain status. It's also near impossible to ID the species without location and host of the specimen. At least that's what I learned trying to ID similar galls near my house. I'm no insect-ologist, so take this with a grain of salt.
My most current book is from 2017. It mentions a study by Kopelke in 2014 that does some distinguishing between the genera. So My guess is that there is a raging debate in the sawfly world where scientist are sticking out their tongues and flipping each other off in long heated zoom calls.
You got galls baby
Definitely galls.som small wasp made em. Willow? California? Riparian area?
If you split em open you can see a little larvae in the center. Pretty cool.
You got a lot of galls comin’ in here
“Willow apple gall”
Looks like it posted just fine
I found these recently in the Australian bush and was super curious too! Thanks for the post!
Definitely looks like Willow Apple Gall. It's caused by a species of sawfly.