Paleacrita vernata
(Peck, 1795)
Spring Cankerworm, Spring Cankerworm Moth
Paleacrita vernata is a geometrid known as the spring cankerworm. Males have functional and from February to late May, while females are wingless and climb tree trunks to lay . The are defoliators of deciduous trees and shrubs, with documented feeding on Acer, Ulmus, Betula, Prunus, and Quercus . The species has been observed using flax as a secondary , indicating broader host flexibility than previously recognized.
Pronunciation
How to pronounce Paleacrita vernata: //pæliːˈækrɪtə vɜrˈneɪtə//
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Identification
Males have 11–18 mm in length; females are wingless and must climb vegetation to reach -laying sites. Males in late winter and early spring, distinguishing them from the related fall cankerworm (Alsophila pometaria), which emerges in autumn.
Images
Habitat
Deciduous forests and woodlands; agricultural areas where cultivated flax is present; urban and suburban environments with ornamental and hardwood trees.
Distribution
North America from the Atlantic Ocean west to Alberta, Texas, and California. Documented in Canadian provinces including Alberta, Manitoba, and Saskatchewan, and in the northeastern United States.
Seasonality
males active from February to late May. Winter and early spring ; present following hatch in spring.
Diet
feed on leaves of various deciduous trees and shrubs, especially Acer, Ulmus, Betula, and Prunus . Oaks (Quercus) are also affected. Has been documented feeding on flax (Linum usitatissimum) as a secondary .
Life Cycle
Females climb tree trunks to lay . Eggs hatch into that feed on foliage. First larvae disperse using threads that catch wind, allowing aerial transport to host plants. occurs in soil; emerge the following late winter or early spring. One per year.
Behavior
descend from the on threads when disturbed and can climb back up these threads. Homeowners use sticky around tree trunks to intercept climbing wingless females before -laying.
Ecological Role
Defoliator of deciduous trees; can cause significant tree damage during years. Serves as for various and .
Human Relevance
Considered an occasional pest of ornamental and forest trees. Sticky traps are used as a control measure. Documented as a potential pest of flax .
Similar Taxa
- Alsophila pometaria (Fall Cankerworm)Also has wingless females and similar larval , but emerges in autumn rather than late winter/spring.
- Phigalia strigataria (Small Phigalia)Nearly identical , geographic range, and temporal distribution; also has wingless females and wind-dispersing first .