Found on grapevines in Southeastern Arizona
This is the Achemon Sphinx caterpillar. The caterpillars can be green or reddish brown.
They are found over most of the US and Mexico. The larvae do feed on grape leaves, Virginia creeper, and Ampelopsis (porcelain vine) plants. The caterpillars lose their tails in the last stage before it turns into a pupa. They pupate in the soil.
The adults feed on nectar from flowers. The adults can be seen at dusk feeding…looking kind of like hummingbirds.