Explanation of Names
DERIDENS: from the Latin "deridere" (to deride, mock, laugh at) - referring to the pattern on the forewings, which looks somewhat like a laughing face when the wings are held together at rest, and is the origin of the common name
Adult: forewing pale gray, heavily shaded with darker gray; antemedial (AM) line black, sometimes clearly edged in white; postmedial (PM) line black, scalloped, and edged in white; AM and PM lines connected about halfway down the wing by black line that crosses median; this line partly surrounds a pale gray area bordering the dark-centered orbicular spot, giving the impression of an eye; reniform spot outlined in white, with a line of black filling; subterminal line jagged and shaded in black along inner edge; brownish-gray shading between subterminal (ST) line and black-dashed terminal line; hindwing light grayish-brown, slightly darker toward outer margin
[adapted from description by Lynn Scott]
United States except southwestern states, plus southern Canada but apparently absent from Alberta
adults fly from May to August in the north; extended season in Florida
larvae feed mostly on leaves of beech; other hostplants include birch, elm, maple, oak
In this series of images, you can see the face changing from one of mostly yellow to more and more black and finally the classic black face with just small yellow triangles left.