At this point, late in the season, you have lost this crop of hops. Be prepared to deal with the problem from the outset next year.
Till the soil a couple times this fall to expose larvae to birds and predator insects.
Next year: (1) Spreading a line of diatomaceous earth around the base of young plants sets up a barrier to larvae. Diatomaceous earth, the fossilized, abrasive remains of prehistoric sea life, literally lets you draw a line in the dirt thats deadly to any larvae that pass over. (2) Scatter bran or corn meal mixed with Bacillus Thuringiensis and molasses on the soil surface to attract and kill caterpillars. Neither of the above are harmful to humans or other warm blooded animals.