lesser maple spanworm moth

not listed

NNR - Unranked

SNR - Unranked

not listed

Lesser maple spanworm moth is a white, small to medium-sized, typical geometer moth. It occurs in the United States east of the Great Plains and in adjacent Canadian provinces. It is common in eastern Minnesota. It is found in deciduous and mixed woodlands and adjacent shrublands and thickets. Larvae feed on the leaves of mostly maple, especially red maple, but also on birch, cherry, poplar, fir, hemlock, and tamarack. Adults are active from June to August.

Adults are white, have a slender body, and have broad wings with a wingspan of 11⁄16″ to 1⅛″ (18 to 28 mm). The sense organs attached to the mouth (palpi) are long and beak-like. They extend forward beyond the eyes. On the male, the antennae are feather-like, with branches on both sides of most segments. On the female they are thread-like, with no branches. The forewings have broken, orangish-brown, antemedial (AM), median, postmedial (PM), and subterminal (ST) lines. Each line widens into a spot at the leading (costal) margin. The PM line is the most complete and continues onto the hindwing. On some individuals only the spots on the costal margin are visible.

The caterpillar is about ¾″ long and green with white or yellowish lines.

Wingspan: 11⁄16″ to 1⅛″ (18 to 28 mm)

Deciduous and mixed woodlands and adjacent shrublands and thickets.

One generation per year: June to August

Adults are active at night and will come to lights. The wings are held flat when at rest.

Leaves of mostly maple, especially red maple, but also birch, cherry, poplar fir, hemlock, and tamarack.

Sources

4, 21, 24, 27, 29, 30, 71, 75, 82.

Common

This species was first classified as Itame pustularia then Macaria pustularia. In 2008 it was moved to the genus Speranza, then moved back to the genus Macaria in 2015.

Macaria pustularia (lesser maple spanworm moth)

Macaria pustularia (lesser maple spanworm moth), at the hedgerow at Barnes Prairie, Racine Co., Wisconsin. Photo taken on July 6, 2020.

Butterfly/moth on basil leaf. About 1/2" in size.

Location: Barnes Prairie, Racine Co., WI

Macaria pustularia (lesser maple spanworm moth), at the hedgerow at Barnes Prairie, Racine Co., Wisconsin. Photo taken on July 6, 2020.

Location: Cass County