Relatively large Leaf Miner on a spiny vine leaf. It started on the right side and followed the edge of the leaf to the left side, where the pupa seems to be still in place. Charley Eiseman has suggested that this is a Leaf Miner Fly of the family Agromyzidae and probably a species of Phytomyza. If you look closely, you can see the tiny black dots within the trail that is probably fly excreta.
Forest floor, about 5 km up Mt. Huitepec, west of San Cristobal de Las Casas, Chiapas, Mexico.