This is a pest of California Live Oaks. The adult oakworm moth is tan-to-gray colored with a wing span of about an inch. It lays white eggs twice a year that turn reddish or brown before hatching. The first hatch is in November and overwinters on the leaves, growing and eating more as the weather warms. At full size, the larva is about an inch long with a yellowish green body, dark stripes down the side and large brown head. Outbreaks occur every eight to ten years in the Bay Area. In late March or April, look for little green pellets (droppings) falling from oak trees. A second generation of eggs hatches in mid to late summer. Trees may suffer no permanent damage beyond being unsightly. If you cannot tolerate the worms and their mess, further treatment methods are outlined in the UC Pest Note on California Oakworm.