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Maple Spanworm

Ennomos magnaria

Ennomos magnaria, commonly known as the Maple Spanworm Moth, is a species of moth belonging to the family Geometridae. Geometridae means “earth measurer,” and the caterpillars are fondly nicknamed “inchworms,” “loopers,” and “spanworms” because of their gait. The Maple Spanworm Moth has a wingspan of about 2 inches, with wings that are held at a ~45 degree angle when at rest. Its wings are characterized by shades of brown, tan, and white, and have a distinctive pattern that resembles an autumn leaf.

A fun fact about this species is that its caterpillars have an unusual method of moving – they do not have legs on their middle segments, so they arch their bodies and “loop” forward. The caterpillars of Geometer moths are often called “inchworms,” “loopers,” or “spanworms” due to their characteristic looping gait. The Maple Spanworm Moth can be found throughout North America, with a preference for deciduous forests. It is a nocturnal species and is most active during the late summer and early fall.

 

Habitat
deciduous forests, woodlands, and suburban areas with mature trees
Scientific Name
Ennomos magnaria
Wing Span
43mm to 60mm
General Size
Average
Wing Color
yellow
yellow
Marking's Color
brown
brown
Markings Pattern
Spots

Characteristics describe the physical and behavioral traits that distinguish a species from others. This section helps readers identify and differentiate between similar species, aiding in species identification and reducing the chance of misidentification.

Identifying Characteristics

  1. Unevenly scalloped wings

  2. Redder near wing edges

  3. Speckled with tiny brown spots

The chart displays the months of the year on the x-axis and observations of a particular species on the y-axis, indicating the time of year when each species is most commonly observed. This chart can assist moth watchers and researchers in predicting the best times and locations to observe specific moth species.

A range map is a visual representation of a species' geographical distribution, and it helps naturalists and field researchers quickly determine if a species is likely to be found in a given area, aiding in identification, conservation, and habitat management efforts.