I found this little guy and about a thousand of his buddies on our apple and plum trees, and they are voracious eaters. They are incredibly small, maybe about a half inch long. I’ve been searching for anything even remotely similar and have had no luck on identifying this booger. We live in the middle of Oklahoma, if that’s any help for identifying.
We’re spraying for them now to protect our trees.
Your caterpillar is a Unicorn caterpillar that turns into as unusual of moth as the caterpillar is with it’s coloring and ‘horn’ on the back. This family of moths are called the Prominent moths as many of the caterpillars and sometimes the moths have a prominent feature about them.
Here are photos of the moth and other stages of the caterpillar. Notice the angle that the moth sits in when not in flight…
These are found all over North America in deciduous woodlands and shrubby areas. The larvae are known to feed on apple as well as alder, aspen, white birch,cherries, roses, elm, hawthorn, hickory and willow. Sorry yours ended up on your apple. It is noted that the caterpillars in this genus can eject a stream of formic acid several inches from the gland in the hump!
They over winter as larva under leaf litter…so do you have lots of leaves under your apple trees or nearby?
Sorry they were on your apple…if it were me I would move them to a tree of one of the other species that they feed on. If you have that many, my guess is some would be eaten by birds and not survived too long…but then again with the ability of ejecting formic acid…maybe the birds leave them alone!!
Thanks for sharing this insect!