The gall!

Strolling Riverside Park yesterday, I noticed an unusually mottled leaf.Turning it over I discovered a world! It looked like something from a sci-fi movie. I went back today to take a picture and found that a few other leaves on the same tree had tiny little sci-fi colonies too!Only one leaf was weakened to the point of falling. With the help of iNaturalist, I was able to learn who I was dealing with: a Hackberry Nipplegall Psyllid! In plainer English that's the nymph of a mini-cicada, or rather, the growth the hackberry is induced to produce around it.Apparently it's not harmful to the tree - not surprising when you consider that this particular insect can live only in this kind of tree. But word is that this isn't just a two-species condominium. There's a particular kind of parasitic wasp that lays its eggs only in the nymphs inside these galls... and then there's whatever fungi are lacing the leaf veins and giving the maturest galls I found their Doctor Seussian tufts!