eggs are inserted singly near the edge of young leaves of oak and chestnut before the leaves have fully opened. Eggs hatch in 7 to 15 days. The mine is a narrow, linear passage extending toward the leaf margin. This early stage of the mine is usually obliterated as the mine is enlarged and often causes a characteristic fissure to form eventually in the leaf. Immediately following the serpentine stage, the mine broadens to form a large, somewhat inflated blotch. Larva usually sweeps in small circles of 5 mm or more radius in feeding, with its anal end functioning as a pivot. The final outline of the mine often results from a series of these semicircles marked by a series of fine, concentric curved lines. The blotch becomes full depth and semitransparent. Consequently, the larva and its dark frass may be easily observed. After feeding for 7 to 10 days the larva drops to the ground and burrows into the soil as deep as 12 inches. A relatively tough oval cocoon measuring approximately 3 mm long and 2 mm in diameter is spun of silk and small particles of soil. The larva diapauses inside this cocoon for several months and pupates in winter. After emerging from the ground, the pupa remains quiescent for an indefinite period until final ecdysis can be performed. Rather soon after emerging from the pupal shell, the adult is capable of flight
(1) [Randy Hardy]