The fungus that causes maple leaf blister overwinters in bud scales and attacks developing leaves early in spring. Lesions are a mix of lighter brown to black. If you choose to contribute, you may go to and click on the yellow “donate” button. Compared with maple anthracnose, the spots are more rounded in shape and contain small, raised blisters. Naturally Curious is supported by donations. Orange-headed, metallic blue-winged adult moths will emerge in the spring, leaving their leaf homes behind.īecause leaves have produced most of the sugar they are going to produce by late summer, the feeding behavior by the moth larvae that occurs from August until leaf fall isn’t a threat to the health of the tree unless complete defoliation occurs for three consecutive years or more. When September comes, the larvae are mature and descend to the ground, carrying their homes with them as they move into the topsoil to pupate. Poster to help identify some leaf, trunk and root diseases of sugar maples. It is this feeding that causes the “punch holes.” As the larva grows, it cuts larger and larger discs to form its case. They take two of these discs and fasten them together with silk, forming a protective case around themselves as they consume additional tissue between the leaf veins. A bit later in the summer the larvae start using their mandibles to cut out round discs of leaf tissue. One of the easiest ways to differentiate Norway maple from sugar maple is to cut the petiole (or leaf stalk) or vein and if a milky substances oozes out, it is a Norway maple.
The mines are barely discernible, as the larvae are so small at this stage.
At the beginning of the summer, leafcutter larvae hatch and begin mining tissue between the upper and lower layers of maple leaves. The Maple Leafcutter Moth ( Paraclemensia acerifoliella) is the hole-punching culprit. This time of year it looks like someone has visited every other Sugar Maple (and to a lesser extent, Red Maples and birches) leaf with a hole punch.
0 kommentar(er)
