American Dagger

Wonderful! Reading the description of the larva of this species by David Wagner in his book "Caterpillars of Eastern North America," I think this is a good match: "Caterpillar is densely covered with white or pale yellow hairs (early and middle instars more yellow), with a pair of diverging thin black lashes on A1 and A3 (first and third abdominal segments), a single tuft of black hairs on A8. Head smooth and shiny black."