American Dagger Moth
Acronicta americana (Harris)
Primarily silver maple but occasionally other maples including boxelder
Damage and Diagnosis
Life History and Habits
The adult stage is a moderately large (wingspan of about two inches) brown moth named after a dagger-like marking on the forewing. After emerging from the overwintering pupa, adult moths are present through much of spring and lay eggs on the newly emerged foliage of maple. The eggs hatch in late spring and larvae feed throughout the summer. In early fall they crawl down the tree trunk in search of pupation sites and may be encountered dozens of yards from the host tree at this time. Finding a suitable sheltered spot they spin a dense silken cocoon and pupate within it. There is one generation per year.
Other dagger moths can be found in the region, including the poplar dagger moth (A. leporina L.), that feeds on poplar, willow and birch. Habits and general appearance of the caterpillars are generally similar.
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