Dasineura aceris

Recognizable damage appeared on the new leaves while they were still curled. Affected leaves turned upwards and developed shallow pouch-like distortions on the leaf blades near the veins. About 20% of the infested leaves continued to grow and enlarge but often became distorted and tattered when growth tensions caused ruptures. When the occurrence was discovered in early July, the size of many of the larvae suggested that first oviposition must have taken place several weeks previously. Although oviposition was not observed, a cluster of unhatched but apparently healthy eggs was located on the upper surface of a partly folded leaf on July 25. The masses of white or pale cream larvae were found throughout the summer, often mixed instar groups of 20 or more in tightly curled leaves. As the leaves became distorted by the formation of the pouches, the larvae could be found in the crevices between the swellings and the larger veins. Late instar larvae were covered with a dense webbing under which pupation took place (Fig. 1).

From the rather preliminary information obtained, Dasineura aceris, in the Sudbury area, emerges in the spring and infests the new leaves of silver maple as they begin to uncurl. Throughout the summer the various stages overlap until the leaves are too well developed for further oviposition.

Rhabdophaga aceris

On Acer saccharinum.

Cecidomyia aceris, n. sp.

Larva on the surface of the leaves of Acer dasycarpum [saccharinum], Ehrhart, (White or Silver Maple), pale or whitish, the alimentary canal appears through the translucent integument as a greenish stripe; often single specimens on the leaf, more frequently in scattering groups of three to a dozen on the same leaf; the leaves become curled and irregularly contorted, but there are no galls; at length, after the maturity of the insect, the leaves become dry and black.

Dasyneura sp.

Acer rubrum

Distorted, rolled leaves bearing cocoons, possibly identical with the preceding [Dasineura rileyana]. Summer.

Rhabdophaga aceris

Acer saccharinum

Free larvae on irregularly curved leaves.

Dasineura aceris

Host: Acer saccharinum

Crumpled leaf
Damage usually occurs on expanding leaves, which grow distorted and crumpled.

Range: Ontario to WI, south to MD and KS